D-Link DI-206 User Manual

Rev. 04 (July 2000)

6DI206….04

Printed in Taiwan

DI-206

ISDN Router

User’s Guide

RECYCLABLE

Copyright Statement

Copyright ©2000 D-Link Corporation

No part of this publication may be reproduced in any form or by any means or used to make
any derivative such as translation, transformation, or adaptation without permission from D­Link Corporation/D-Link Systems Inc., as stipulated by the United States Copyright Act of

1976.

Trademarks

D-Link is a registered trademark of D-Link Corporation/D-Link Systems, Inc.

All other trademarks belong to their respective owners.

FCC Warning

This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to Part
15 of the FCC Rules. These limits are d esi gned to provide reason able protection again st harmful interference in
a residential installation. This equipment generates, uses, and can radiate radio frequency energy and, if not
installed and used in accordance with the inst ructions, may cause harmful interference to radio communications.
However, there is no guarantee that interference will not occur in a particular installation. If this equipment does
cause harmful interference to radio o r t elevision reception, which can be determined by turning t he equipment
off and on, the user is en couraged to try to correct th e interference by one or more of the following measures:

• Reorient or relocate the receiving antenna.

• Increase the separation between the equipmen t and receiver.

• Connect the equipment into an outlet on a circuit different from that to which the receiver is connected.

• Consult the dealer or an experienced radio/TV technician for help.

Shielded interface cables must b e used in order to comply with emission l i mits.

You are cautioned that changes or modifications not expressly approved by the party responsible for compliance
could void your authority to operate the equipment.

This device complies with part 15 of the FCC Rules. Operation is subject to the following two conditions: (1)
This device may not cause harmful interference, and (2 ) this device must accept any interference received,
including interference that may cause undesired operation.

CE Mark Warning

This is a Class B product. In a domestic environment, this product may cause radio interference in which case
the user may be required to take adequate measures.

Limited Warranty

Hardware:

D-Link warrants each of its hardware products to be free from defects in workmanship and materials under normal use and
service for a period commencing on the date of purchase from D-Link or its Authorized Reseller and extending for the length of
time stipulated by the Authorized Reseller or D-Link Branch Office nearest to the place of purchase.

This Warranty applies on the condition that the product Registration Card is filled out and returned to a D-Link office within
ninety (90) days of purchase. A list of D-Link offices is provided at the back of this manual, together with a copy of the
Registration Card.

If the product proves defective within the applicable warranty period, D-Link will provide repair or replacement of the product.
D-Link shall have the sole discretion whether to repair or replace, and replacement product may be new or reconditioned.
Replacement product shall be of equivalent or better specifications, relative to the defective product, but need not be identical.
Any product or part repaired by D-Link pursuant to this warranty shall have a warranty period of not less than 90 days, from
date of such repair, irrespective of any earlier expiration of original warranty period. When D-Link provides replacement, then
the defective product becomes the property of D-Link.

Warranty service may be obtained by contacting a D-Link office within the applicable warranty period, and requesting a
Return Material Authoriza tion (RMA) number. If a Reg istration Card for the product in question has not been returned to
D-Link, then a proof of purchase (such as a copy of the dated purchase invoice) must be provided. If Purchaser's circumstances
require special handling of warranty correction, then at the time of requesting RMA number, Purchaser may also propose
special procedure as may be suitable to the case.

After an RMA number is issued, the defective product must be packaged securely in the original or other suitable shipping
package to ensure that it will not be damaged in transit, and the RMA number must be prominently marked on the outside of
the package. The package must be mailed or otherwise shipped to D-Link with all costs of mailing/shipping/insurance prepaid.
D-Link shall never be responsible for any sof tw are, firmware, information, or memory data of Purchaser contained in, stored
on, or integrated with any product returned to D-Link pursuant to this warranty.

Any package returned to D-Link without an RMA number will be rejected and shipped back to Purchaser at Purchaser's
expense, and D-Link reserves the right in such a case to levy a reasonable handling charge in addition mailing or shipping
costs.

Software:

Warranty service for software products may be obtained by contacting a D-Link office within the applicable warranty period.
A list of D-Link offices is provided at the back of this manual, together with a copy of the Registration Card. If a Registration
Card for the product in question has not been returned to a D-Link office, then a proof of p urchase (such as a copy of the dated
purchase invoice) must be provided when requesti ng warranty service. The term "purchase" in this software warranty refers
to the purchase transaction and resulting license to use such software.

D-Link warrants that its software products will perform in substantial conformance with the applicable product
documentation provided by D-Link with such software product, for a period of ninety (90) days from the date of purchase from
D-Link or its Authorized Reseller. D-Link warrants the magnetic media, on which D-Link provides its software product,
against failure during the same warranty period. This warranty app lies to purchased software, and to replacement software
provided by D-Link pursuant to this warranty, but shall not apply to any update or replacement which may be provided for
download via the Internet, or to any update which may otherwise be provided free of charge.

D-Link's sole obligation under this software warranty shall be to replace any defective software product with product which
substantially conforms to D-Link's applicable product documentation. Purchaser assumes responsibility for the selection of
appropriate application and system/platform software and associated reference materials. D-Link makes no warranty that its
software products will work in combination with any hardware, or any application or system/platform software product
provided by any third party, excepting only such products as are expressly represented, in D-Link's applicable product
documentation as being compatible. D-Link's obligation under this warranty shall be a reasonable effort to provide
compatibility, but D-Link shall have no obligation to provide compatibility when there is fault in the third-party hardware or
software. D-Link makes no warranty that operation of its software products will be uninterrupted or absolutely error-free, and
no warranty that all defects in the software product, within or without the scope of D-Link's applicable product documentation,
will be corrected.

D-Link Offices for Registration and Warranty Service

The product's Registration Card, provided at the back of this manual, must be sent to a D-Link office. To obtain an RMA
number for warranty service as to a hardware product, or to obtain warranty service as to a software product, contact the
D-Link office nearest you. An address/
telephone/fax/e-mail/Web site list of D-Link offices is provided in the back of this manual.

Wichtige Sicherheitshinweise

1. Bitte lesen Sie sich diese Hinweise sorgfältig durch.

2. Heben Sie diese Anleitung für den spätern Gebrauch auf.

3. Vor jedem Reinigen ist das Gerät vom Stromnetz zu trennen. Vervenden Sie keine Flüssig- oder Aerosolreiniger. Am
besten dient ein angefeuchtetes Tuch zur Reinigung.

4. Um eine Beschädigung des Gerätes zu vermeiden sollten Sie nur Zubehörteile verwenden, die vom Hersteller zugelassen
sind.

5. Das Gerät is vor Feuchtigkeit zu schützen.

6. Bei der Aufstellung des Gerätes ist auf sichern Stand zu achten. Ein Kippen oder Fallen könnte Verletzungen
hervorrufen. Verwenden Sie nur sichere Standorte und beachten Sie die Aufstellhinweise des Herstellers.

7. Die Belüftungsöffnungen dienen zur Luftzirkulation die das Gerät vor Überhitzung schützt. Sorgen Sie dafür, daß diese
Öffnungen nicht abgedeckt werden.

8. Beachten Sie beim Anschluß an das Stromnetz die Anschlußwerte.

9. Die Netzanschlußsteckdose muß aus Gründen der elektrischen Sicherheit einen Schutzleiterkontakt haben.

10. Verlegen Sie die Netzanschlußleitung so, daß niemand darüber fallen kann. Es sollete auch nichts auf der Leitung
abgestellt werden.

11. Alle Hinweise und Warnungen die sich am Geräten befinden sind zu beachten.

12. Wird das Gerät über einen längeren Zeitraum nicht benutzt, sollten Sie es vom Stromnetz trennen. Somit wird im Falle
einer Überspannung eine Beschädigung vermieden.

13. Durch die Lüftungsöffnungen dürfen niemals Gegenstände oder Flüssigkeiten in das Gerät gelangen. Dies könnte einen
Brand bzw. Elektrischen Schlag auslösen.

14. Öffnen Sie niemals das Gerät. Das Gerät darf aus Gründen der elektrischen Sicherh eit nur von authorisiertem
Servicepersonal geöffnet werden.

15. Wenn folgende Situationen auftreten ist das Gerät vom Stromnetz zu trennen und von einer qualifizierten Servicestelle zu
überprüfen:

a – Netzkabel oder Netzstecker sint beschädigt.
b – Flüssigkeit ist in das Gerät eingedrungen.
c – Das Gerät war Feuchtigkeit ausgesetzt.
d – Wenn das Gerät nicht der Bedienungsanleitung ensprechend funktioniert oder Sie mit Hilfe dieser Anleitung keine

Verbesserung erzielen.
e – Das Gerät ist gefallen und/oder das Gehäuse ist beschädigt.
f – Wenn das Gerät deutliche Anzeichen eines Defektes aufweist.

16. Bei Reparaturen dürfen nur Orginalersatzteile bzw. den Orginalteilen entsprechende Teile verwendet werden. Der
Einsatz von ungeeigneten Ersatzteilen kann eine weitere Beschädigung hervorrufen.

17. Wenden Sie sich mit allen Fragen die Service und Repartur betreffen an Ihren Servicepartner. Somit stellen Sie die
Betriebssicherheit des Gerätes sicher.

18. Zum Netzanschluß dieses Gerätes ist eine geprüfte Leitung zu verwenden, Für einen Nennstrom bis 6A und einem
Gerätegewicht grßer 3kg ist eine Leitung nicht leichter als H05VV-F, 3G, 0.75mm2 einzusetzen

Table of Contents

NTRODUCTION

I

Product Features............................................................................................................................1

Applications for your DI-206 .........................................................................................................3

Internet Access.............................................................................................................................................3

Network Address Translation (NAT)...........................................................................................................3

LAN-to-LAN Enterprise Connections.........................................................................................................3

Telecommuting Server.................................................................................................................................3

What This Manual Covers..............................................................................................................3

What This Manual Doesn’t Cover..................................................................................................4

Other Resources .............................................................................................................................4

Packing List....................................................................................................................................5

Additional Installation Requirements .............................................................................................5

NSTALLATION

I

Ordering Your ISDN Line...........................................................................................................................6

The DI-206 Front Panel.................................................................................................................6

The DI-206 Rear Panel...................................................................................................................7

................................................................................................1

.................................................................................................6

Telephone Features........................................................................................................................8

Installation and Initial Configuration ............................................................................................8

A Warning on Connection Cables................................................................................................................9

Step 1 - Setting up the Console....................................................................................................................9

Step 2 - Connecting the Console to the Router............................................................................................9

Step 3 - Connecting an ISDN Line to the Router.......................................................................................10

Step 4 - Connecting a Telephone or Fax Machine to the Router...............................................................10

Step 5 - Connecting Ethernet Cables to the Router.................................................................................... 10

Step 6 - Powering Up Devices for Initial Configuration ............................................................................12

Step 7 - Initial Configuration of the Router ...............................................................................................12

Step 7 - Configuring the LAN Port............................................................................................................13

Step 8 – Plugging in All Devices...............................................................................................................15

ONFIGURATION AND MANAGEMENT

C

...............................................................16

Console Program Main Menu......................................................................................................16

System Information.......................................................................................................................17

Interface Configuration................................................................................................................18

LAN...........................................................................................................................................................19

ISDN..........................................................................................................................................................19

Network Configuration.................................................................................................................21

IP Stack Configuration...............................................................................................................................22

IP Static Route...........................................................................................................................................25

IP Networking............................................................................................................................................26

Router Advertisement ................................................................................................................................26

SNMP Agent Configuration..........................................................................................................26

SNMP Community Configuration .............................................................................................................27

SNMP Trap Manager Configuration..........................................................................................................28

SNMP Authenticated Trap.........................................................................................................................28

Advanced Functions .....................................................................................................................29

Remote Access Configuration....................................................................................................................29

DHCP Configuration .................................................................................................................................38

Filter Configuration ...................................................................................................................................42

Multiple Home Configuration....................................................................................................................47

Static ARP..................................................................................................................................................49

NAT Configuration....................................................................................................................................50

Telnet/Discovery Enable............................................................................................................................60

DNS Configuration....................................................................................................................................61

Radius Configuration .................................................................................................................................63

Multi-Link PPP Configuration...................................................................................................................63

Admin Configuration....................................................................................................................65

System Maintenance.....................................................................................................................66

System Status.............................................................................................................................................66

Statistics.....................................................................................................................................................67

Runtime Tables..........................................................................................................................................70

Log and Trace............................................................................................................................................ 73

Diagnostic..................................................................................................................................................77

Software Update.........................................................................................................................................80

System Restart............................................................................................................................................81

Factory Reset.............................................................................................................................................82

System Settings Backup/Restore................................................................................................................82

PROM S

SING TELNET

U

YSTEM CONFIGURATION

System Configuration.................................................................................................................................85

TCP/IP Parameters Configuration..............................................................................................................86

System Reset..............................................................................................................................................86

Software Update.........................................................................................................................................87

EEPROM Factory Reset............................................................................................................................88

Execute Bootload ............................................................................................................... ........................88

...................................................................85

..............................................................................................90

Telnet Configuration.....................................................................................................................90

Using Telnet via LAN ................................................................................................................................90

Using Telnet via ISDN...............................................................................................................................90

System Timeout .........................................................................................................................................91

SING

U

RADIUS A

UTHENTICATION

.................................................................92

Installing a RADIUS Server..........................................................................................................92

Configuring the DI-206 for RADIUS Authentication...................................................................92

Adding Users to the RADIUS Database.......................................................................................93

PPENDIX

A

ROUBLESHOOTING

A - T

.................................................................94

Some Common Problems With the DI-206...................................................................................94

None of the LEDs are on when you power up the router...........................................................................94

Connecting the RS-232 cable, cannot access the console program............................................................94

Problems With the ISDN Line.......................................................................................................94

Problems with the LAN Interface..................................................................................................94

Can’t PING any station on the LAN..........................................................................................................94

PPENDIX

A

B - IP C

ONCEPTS

..........................................................................96

IP Addresses.................................................................................................................................96

IP Network Classes....................................................................................................................................96

Subnet Mask..................................................................................................................................97

PPENDIX

A

IP Protocol Numbers....................................................................................................................98

IP Port Numbers ...........................................................................................................................98

C – IP P

ROTOCOL AND PORT NUMBERS

.........................................98

PPENDIX

A

PPENDIX

A

PPENDIX

A

Configuration File Example.......................................................................................................102

NDEX

I

.........................................................................................................104

ECHNICAL SPECIFICATIONS

D - T

E – C

F – C

OUNTRY

ONFIGURATION FILE

ID N

UMBERS

.....................................................99

.........................................................101

............................................................102

Introduction

Congratulations on your purchase of a D-Link DI-206 series remote access router
with integrated Ethernet hub and ISDN T/A. No larger than an ordinary modem,
your router offers inexpensive yet complete telecommunications and internetworking
solutions for your home or branch office. It is ideal for everything from Internet
browsing to receiving calls from Remote Dial-in Users and making connections to
other LANs via Remote Nodes.

Distinguishing features of the DI-206 include support for a full range of networking
protocols, including TCP/IP (Transmission Control Protocol/Internet Protocol, also
known as IP).

This complete solution also includes remote dial-in user support, an Internet single­user account (Network Address Translation) option, extensive network management
capabilities, and solid security features.

DI-206 ISDN Remote Router

Product Features

The DI-206 router is packed with features that give it the flexibility to provide a
complete networking solution for almost any small to medium-sized office
environment.

Ease of Installation

Your DI-206 is a self-contained unit that is quick and easy to install. Physically, it
resembles an external modem; however, it is a combination ISDN router and 10
Mbps Ethernet hub, and it uses twisted-pair Ethernet cables to connect to the host
network.

Built-in Hub

As a 10 Mbps Ethernet hub, your DI-206 provides six ports for connecting standard
Ethernet devices. Five ports are designed for connecting network end nodes—single­user computers, servers, bridges, other routers, etc.—through standard “straight­through” twisted-pair cables; the sixth is wired for making an “uplink” connection to
another hub or switch through the same type of straight-through cable used to
connect end nodes.

ISDN Basic Rate Interface (BRI)

Using a standard S/T the DI-206 supports DSS1 ISDN switches. The two ISDN B­channels can be used independently for two destinations, or they can be bundled
together for one high-bandwidth connection supporting bandwidth-on-demand.

1

DI-206 ISDN Remote Router

ISDN Leased Line

If the router is set up for an ISDN leased line, it can automatically initialize the
leased-line connection each time it is powered up.

Standard Phone Jacks

The router is equipped with two standard phone jacks for connecting telephones, fax
machines, or modems. This allows the ISDN line to be used for voice as well as data
calls.

Dial On Demand

The Dial On Demand feature allows a DI-206 to automatically place a call to a
Remote Node whenever there is traffic coming from any workstation on the LAN
(Local Area Network) to that remote site.

Bandwidth On Demand

Your DI-206 supports bandwidth up to 128 kbps over a single ISDN BRI line. It
incorporates MLPPP (Multi-Link PPP) to bundle two B channels over a BRI line. In
addition, the router dynamically allocates bandwidth between the two B channels,
increasing or decreasing bandwidth as needed to allow for greater efficiency in data
transfer. It supports BAP (Bandwidth Allocation Protocol) and BACP (Bandwidth
Allocation Control Protocol) to manage the number of links in the multi-link bundle.

Full Network Management

The DI-206 incorporates SNMP (Simple Network Management Protocol) support
and menu-driven network management via an RS-232 or Telnet connection.

RADIUS (Remote Authentication Dial In User Service)

The RADIUS feature allows you to use a central external Unix or NT-based server
to support thousands of users.

PPP Security

The DI-206 supports PAP (Password Authentication Protocol) and CHAP
(Challenge Handshake Authentication Protocol).

RIP-1/RIP-2

Your DI-206 supports both RIP-1 and RIP-2 (Routing Information Protocol versions
1 and 2) exchanges with other routers.

DHCP Support (Dynamic Host Configuration Protocol)

DHCP (Dynamic Host Configuration Protocol) allows IP addresses to be
automatically and dynamically assigned to hosts on your network.

2

Data Compression

The DI-206 incorporates Stac data compression and CCP (Compression Control
Protocol).

Networking Compatibility

The DI-206 is compatible with remote access products from other companies such as
Ascend, Cisco, and 3Com. Furthermore, they support Microsoft Windows 95 and
Windows NT remote access capability.

Applications for your DI-206

Some applications for the DI-206 include:

Internet Access

Your DI-206 supports TCP/IP protocol, which is the language used for the Internet.
It is also compatible with access servers manufactured by major vendors such as
Cisco and Ascend.

DI-206 ISDN Remote Router

Network Address Translation (NAT)

For small office environments, the DI-206 allows multiple users on the LAN to
access the Internet concurrently through a single Internet account. This provides
Internet access to everyone in the office for the price of a single user.

NAT address mapping can also be used to link two IP domains via a LAN-to-LAN
connection.

LAN-to-LAN Enterprise Connections

The DI-206 can dial to or answer calls from another remote access router connected
to a different LAN. The DI-206 supports TCP/IP and has the capability to bridge any
Ethernet protocol.

Telecommuting Server

The DI-206 allows Remote Dial-in Users to dial in and gain access to your LAN.
This feature enables users that have workstations with remote access capabilities,
e.g., Windows 95, to dial in using an ISDN terminal adapter (TA) to access the
network resources without physically being in the office.

What This Manual Covers

This manual is divided into eleven parts.

3

DI-206 ISDN Remote Router

Chapter One, “
implemented in the DI-206 as well as product features.

Chapter Two, “
installing the router.

Chapter Three,
explanations for the console program that is used to setup and configure the
router.

Chapter Four, “
PROM program, an abbreviated version of the console program that is used
to download new software into the router in case of problems with the
console program.

Chapter Five, “
configure the router.

Chapter Six, “
use a RADIUS server to manage user authentication and centralize
passwords.

Appendix A, “
up the router and suggests solutions.

Introduction,”

Installation,”

“Configuration and Management,”

PROM System Configuration

Using Telnet

Using RADIUS Authentication

Troubleshooting

describes many of the technologies

is designed as a step-by-step guide to

,” provides information on the

,” describes how to setup and use telnet to

,” describes how to setup and

,” describes some common problems setting

provides detailed

Appendix B, “
recommendations for setting up an IP network on your LAN.

Appendix C, “
IP settings.

Appendix D, “
DI-206 ISDN router.

Appendix E, “
be entered when setting up the ISDN line on the router. These numbers
have no relation to the International Country Codes used by your telephone
company.

Regardless of the application, it is important that you follow the steps outlined in
Chapter 2, “
then refer to other chapters of the manual depending on your specific installation
requirements.

Installation

IP Concepts

IP Protocol and Port Numbers

Technical Specifications

Country ID Numbers

,” to correctly connect your DI-206 to your LAN. You can

,” gives detailed explanations and

What This Manual Doesn’t Cover

This manual assumes that you know how to use your computer and are familiar with
your communications software. If you have questions about using either one, refer to
the manual for the product.

,” lists many commonly used

,” a list of specifications about the

,” lists country ID numbers which must

Other Resources

For more information about your DI-206 check the following sources:

4

Quick Start Guide.

♦

DI-206 ISDN Remote Router

Support disk containing

♦

RouteMan

, a Windows-based configuration program.

Packing List

Before you proceed further, check all items you received with your DI-206 against
this list to make sure nothing is missing. The complete package should include:

One DI-206 ISDN router.

♦

One power adapter.

♦

One RS-232 cable.

♦

One unshielded twisted-pair (UTP) cable.

♦

One frequently asked questions (FAQ) and application notes diskette.

♦

One Quick Installation Guide.

♦

User’s Guide

♦

This

.

Additional Installation Requirements

In addition to the contents of your package, there are other hardware and software
requirements you need before you can install and use your router. These
requirements include:

An ISDN line.

♦

Ethernet connection(s) to your computer(s).

♦

A computer equipped with an RS-232 port and communications software

♦

configured to the following parameters:

VT100 terminal emulation.

◊

9600 baud.

◊

No parity, 8 data bits, 1 stop bit.

◊

After the router has been successfully connected to your network, you can make
future changes to the configuration using a Telnet client application.

5

DI-206 ISDN Remote Router

Installation

This chapter outlines how to connect your DI-206 to your LAN and ISDN line. Refer
to the diagrams below to identify all of the ports on your device when you make
connections.

Ordering Your ISDN Line

If you do not have an ISDN line installed already, we suggest that you order it from
your telephone company as soon as possible to avoid the long waiting period
common when ordering a new line. Use the information in this section to place the
order. If you have already installed your ISDN line, you can check the following
section to make sure that you can use all the features of your DI-206.

Contact your local telephone company’s ISDN Ordering Center.

1.

Make sure DSS1 switches are available since these are the only switch types

2.

currently supported by the DI-206.
When the telephone company installs your ISDN line, be sure to obtain the

3.

following information:

ISDN switch type.

◊

ISDN telephone number(s).

◊

The DI-206 Front Panel

Names and descriptions of your router’s front panel LEDs are given below:

POWER

plug the power adapter into a suitable AC outlet.

— Comes on as soon as you connect the router to the power adapter and

TEST
ISDN – LINK

interface and it has been successfully initialized.

ISDN – B1

channel is making or receiving a call.

— Should be blinking if the router is functioning properly.

— Indicates that the router has an ISDN line connected to the ISDN

and

— On if there is an active ISDN session on that channel or if that

B2

6

DI-206 ISDN Remote Router

ETHERNET – COL

when two devices have attempted to transmit at the same time.

ETHERNET – Uplink

when a connection to an Ethernet device is detected. The indicator blinks when a
transmission is received from the device, and shines yellow when the device has
been partitioned, that is, temporarily isolated from the LAN because of excessive
collisions (partitioning is a required capability of all Ethernet hubs).

PHONE – 1
PHONE – 2

— Lights up when standard phone port 1 is in use.
— Lights up when standard phone port 2 is in use.

The DI-206 Rear Panel

— Shines yellow when a collision occurs on the LAN, that is,

and 1 through 5— Each of these indicators shines green

POWER

— This socket is an 18 volt, 750mA power input jack. If the power adapter
included with the router has been lost or misplaced, please ensure that the
replacement adapter meets both the voltage and amperage requirements.

CONSOLE

– This 9-pin RS-232 port is used for connecting a console or PC
running a terminal emulation program. It provides out-of-band management
capabilities for the initial setup and configuration of the router.

PHONE 1

and 2 – These normal telephone jacks can be used to connect telephones
or fax machines to the router for use over the ISDN lines. Plug telephone devices
into these jacks as you normally would into a telephone wall socket.

– This socket is used to connect the ISDN line to either an NT-1 or directly to

ISDN

the ISDN wall jack, depending on the type of service delivered by your phone
company.

ETHERNET

– The six Ethernet ports function as a normal 10 Mbps 10BASE-T

Ethernet hub.

Uplink

•

– This port is used to connect the router to another hub using a

straight-through twisted-pair cable.

Ports 1x to 5x

•

– These five ports can be used to connect end-stations to

the router using straight-through cables.

7

DI-206 ISDN Remote Router

Telephone Features

Up to two telephones can be attached to the DI-206 router via the Phone 1 and
Phone 2 telephone jacks located on the rear of the router. The router enables the
attached telephones to have a number of features which may or may not be found on
normal telephones and are described below. Additional features which must actually
be configured are described in the
section of this manual.

Interface Configuration

–

ISDN

sub-menu

♦ Hold

– This feature is very similar with and can work in conjunction with call

waiting as defined in the

Interface Configuration

this manual. Press Flash 0 to place someone on hold (

–

ISDN

Flash

is a very brief

sub-menu section of

hanging up of the phone). Press Flash 2 to take the caller off hold.

♦ Hold (and pick up from another location)

- Telephones connected to the
router can be put on hold by pressing Flash 71, 72, 73, or 74. Press the same
number to take the caller off hold and speak from another phone on your
telephone network.

♦ Call forwarding

– If you wish to forward incoming calls to a different
telephone, press *77* and then the phone number you wish to forward the call
to. All incoming calls will automatically be forwarded to the phone number
entered. Press #77# to cancel call forwarding.

♦ Three-person conference call

– To use this feature, conference calling must be
enabled by the telephone company. After this is done, pick up a phone and place
a call. After connected, press Flash 0 (refer to

s

Configuration – ISDN

ub-menu section of this manual) and dial the second

call waiting

in the

Interface

number. After connected, press flash 3 to speak to both parties at the same time.
Press Flash 0 to hang up with the first party called. Press flash 1 to hang up with
the second party called.

♦ Call transfer

– To transfer a call to the other phone jack on the router: if using

Phone 1, press flash 20. If using Phone 2, press flash 10.

Installation and Initial Configuration

This section discusses the different connections that can be made to the router when
setting it up.

Initially, you will only wish to connect the console to the router in order to configure
the other ports. Once that is complete, you will need to turn off the power to the
router and plug in the connection cables to the other devices. Next, power on the
other devices. When they have finished powering up, power on the router. Each of
these steps is described in detail in the sections below. Please skip any setting
adjustments that do not apply to your configuration needs.

8

For the initial configuration of your DI-206, you must use an RS-232 console
connection, either to a computer running serial communications software or to a
serial data terminal.

After the router has been successfully installed and the initial configuration is
complete, you can continue to modify settings through the console, or you can
change configuration settings through a remote Telnet connection or through a web
browser. See the chapters entitled “

Telnet”

for detailed instructions on using Telnet to configure your DI-206.

A Warning on Connection Cables

ISDN and Ethernet cables are very similar to each other. It is important that you use
the correct cable for each connection; otherwise, your router could be damaged.

Before connecting or disconnecting an RS-232 cable between two devices, turn both
devices off to avoid any chance of damaging them.

DI-206 ISDN Remote Router

Configuration and Management”

and “

Using

Step 1 - Setting up the Console

The initial setup of the DI-206, requires connecting a console to the 9-pin RS-232
Diagnostic port on the router’s rear panel. A serial cable is supplied with the
router in order to make this connection. A console can be a terminal, such as a
VT-100, or a normal PC running terminal emulation software (such as Microsoft
HyperTerminal, included with Windows). The terminal emulation software needs
to be configured to the following parameters:

VT100 terminal emulation

◊

9600 baud

◊

No parity, 8 data bits, 1 start bit, 1 stop bit

◊

No flow control

◊

Step 2 - Connecting the Console to the Router

A serial cable is included in the DI-206 package. To connect this cable, plug its
nine-pin connector into the 9-pin RS-232 Diagnostic port on the router’s rear panel,
then connect the other end to the serial port on the rear of your computer or data
terminal.

Please make sure both machines are turned off before making this connection.
After the connection is made, first power on the console. If you are using a PC, run

the terminal emulation software at this time. After the PC and the terminal emulation
software are up and running, power on the router.

9

DI-206 ISDN Remote Router

Using the Console

The Console Program is the interface that you will be using to configure your DI-

206. Several operations that you should be familiar with before you attempt to
modify the configuration of your router are listed below:

♦ Moving the Cursor

Within a menu, use <tab> and arrow keys to navigate

through different information fields.

♦ Moving Forward to Another Menu

the current one, use <tab> or arrow keys to position the cursor on the sub­menu item and press <Enter> to view the selected sub-menu.

♦ Entering Information

There are two types of fields that you will need to fill
in. The first requires you to type in the appropriate information. The second
gives you choices to choose from. In the second case, press the space bar to
cycle through the available choices. Upon configuring all fields the sub-menu,
position the cursor on SAVE and press <Enter> to save, or position the cursor
on EXIT to cancel.

♦ Refresh Screen

Console screens are notorious for becoming garbled. When

this happens, simply press <Ctrl> + <R> to refresh the contents of the screen.

Step 3 - Connecting an ISDN Line to the Router

Your phone company will provide an S/T interface into your home or office. Plug
the ISDN line from the router directly into the ISDN wall socket provided by your
phone company.

To move forward to a sub-menu below

Step 4 - Connecting a Telephone or Fax Machine to the Router

You can connect a regular telephone, fax machine, or modem to your router to be
used for analog calls. Note that the router’s other functions all work the same
whether you connect an analog device or not.

To connect an analog device, just plug one end of the device’s cord into one of the
sockets on the back of the router marked PHONE 1 or PHONE 2.

To have incoming calls directed to a device on a PHONE jack, you must enter the
telephone number for the phone in the console program under the

Configuration, ISDN

submenu.

Step 5 - Connecting Ethernet Cables to the Router

Your DI-206 has six ports for connecting 10BASE-T Ethernet devices to form a
LAN. The jacks for ports 1 through 5 are wired to let you connect network end nodes
(computers, servers, bridges, other routers, etc.) using standard “straight-through”
EIA (Electronic Industries Association) Category 3 or higher twisted-pair cables.
The jack for the sixth port is labeled Uplink and is wired to let you connect to

Interface

10

DI-206 ISDN Remote Router

another 10Mbps Ethernet or dual-speed hub using a straight-through cable, or an end
node using a cross-wired cable.

Please refer to the following chart when deciding on the type of cable necessary for a
given connection:

DEVICE PORT

USED

Normal

Router Server (or PC) Straight-Through (||)

Uplink

DEVICE BEING

CONNECTED

Hub or
Switch

Hub or
Switch

Server (or PC) Crossover (X)

PORT

TYPE

Normal Crossover (X)
Uplink Straight-Through (||)

Normal Straight-Through (||)
Uplink Crossover (X)

CABLE TO USE

The figure below shows how to make an Ethernet connection between the router and
a network end node.

Important Notes on Ethernet Connections

Observe the following rules when connecting devices with twisted-pair Ethernet
cables:

For both end-node and uplink connections, use only EIA Category 3 or higher-

•

grade twisted-pair data cables with RJ-45 plugs. In almost all cases, only
standard straight-through cables are needed.

Make sure no cable is more than 100 meters (328 feet) long.

•

When uplinking two hubs together with a straight-through cable, use an

•

uplink-type jack at one end, and an end-node-type jack at the other.
If uplinking more than two hubs together, observe the 5-4-3 rule: no signal, in

•

order to go from one end node to another, must ever pass through more than
five twisted-pair cables, four repeaters (that is, hubs), and three uplink cables.

11

DI-206 ISDN Remote Router

This is the maximum signal path in twisted-pair Ethernet. Also be sure never
to allow a signal loop to form.

Note that you can connect an end node through the Uplink jack, but to do so
you must use a cross-wired cable or cable converter.

Step 6 - Powering Up Devices for Initial Configuration

Plug in the included 18V DC, 750 mA power adapter into the power jack on the
router’s rear panel.

You should have now connected the RS-232 cable to the console, the ISDN phone
line, one or more Ethernet cables, and the power adapter.

At this point in the installation process you can now power up the console computer,
run the terminal emulation software (if necessary), and then power up the DI-206.

Step 7 - Initial Configuration of the Router

After the console is properly connected and both devices are powered on as
described in the preceding sections, you should see the router run through the power
on self test (POST). Finally, it will arrive at the logon screen shown below. If the
login screen does not appear, press <Ctrl> + <R> to refresh the screen.

12

DI-206 ISDN Remote Router

To log on to the router, use the factory set username and password “Admin”
(without the quotes). Please note that the user name and password are case-sensitive.

Upon entering the username and password (using the <tab> key to jump to the next
field), position the cursor on OK and press <Enter>. You will then see the following

Main Menu

:

Step 7 - Configuring the LAN Port

Preparing the router for connection to a LAN only requires enabling the LAN port,
enabling IP networking, assigning the LAN port an IP address and enabling Telnet
(if necessary). After the LAN port is configured, all other features on the router can
be configured remotely through the LAN by using the included Windows-based
Router Configuration Utility or Telnet. Regardless, the router can always be
configured using a console connected to the RS-232 Console port.

To configure the LAN:

13

DI-206 ISDN Remote Router

1. The LAN port must be enabled in the

Choose

♦

Position the cursor over the State item and press <space bar>. The State will

♦

change from

Position the cursor on the SAVE option at the bottom of the screen and press

♦

Interface Configuration, LAN.

Disable

to

Enable

.

<Enter> to save the new setting.

Choose Exit in the sub-menus to return to the

♦

2. Enable IP Networking

Choose

♦

Position the cursor over the third item IP Networking and press <space

♦

bar> to

Position the cursor on the Save option at the bottom of the screen and press

♦

Network Configuration, IP Configuration.

Enable

it.

<Enter> to save the new setting.

Interface Configuration

Main Menu

sub-menu.

.

3. Assign an IP address to the LAN port in the
of the

♦

Main Menu

Still in

Network Configuration, IP Configuration

above, choose

Enter a valid IP address for the LAN in the first item. You may also enter a

♦

.

IP Stack Configuration, LAN.

Network Configuration

submenu from Step 2

Netmask if you wish. For more information about IP Addresses and Subnet
masks, please refer to Appendix B, “

Position the cursor on the Save option at the bottom of the screen and press

♦

IP Concepts

.”

<Enter> to save the new setting.

Choose EXIT in the sub-menus to return to the

♦

Main Menu

.

4. Enable the Telnet/Discovery function on the router.

From the

♦

Choose the Telnet/Discovery Enable option and then

♦

Position the cursor on the Save option at the bottom of the screen and press

♦

Main Menu

choose

Advanced Functions

.

Enable

Telnet State.

<Enter> to save the new settings.

sub-menu

Choose Exit in the sub-menus to return to the

♦

14

Main Menu

.

The router can now be accessed via the LAN by Telnet, the Web-based DI-206
Router Configuration Utility (included with the router) and other SNMP
management applications.

If you have any questions regarding the settings you made or other settings in the
submenus, please refer to the next chapter “

Step 8 – Plugging in All Devices

You can now plug in and power on all other devices connected to the router. Do not
power on the router yet.

The router is now able to use the LAN ports.
The router must be further configured in order to get the built-in ISDN modem to

function properly, to perform other routing functions, and to manage your IP
network. This can now be done by using the console, the included Web-based
Configuration Utility or Telnet.

DI-206 ISDN Remote Router

Configuration and Management

.”

For more information about configuring or managing the router, please refer to the
next chapter, “

Configuration and Management

.”

15

DI-206 ISDN Remote Router

Configuration and Management

After the initial startup (POST) test, the router will prompt you for login and
password. This is the opening page of the router’s out-of-band configuration
program, called the Console program. The Console program is stored in the Flash
memory chips in the router and the settings are written in EEPROM chips in the
router. It is the most basic level for configuring and managing the router and the
network to which it is connected.

If you’re starting the router for the first time, the default login and password is
“Admin” – the login and password are case-sensitive, alphanumeric characters.

Note that once you are in the
minutes, the router will automatically log you out. Your first endeavor should be to
increase the ‘timeout’ time by adjusting the appropriate value in the

Information

The router can also be configured remotely through a LAN or ISDN connection by
using the included Router Configuration Utility or Telnet. However, if you wish to
do this, the console program must first be used to initially configure the relevant port
on the router. Please see
this manual for more detailed information.

sub-menu.

Step 7 - Initial Configuration of the Router

Console Program Main Menu

The

Main Menu

is shown below.

Main Menu

, if there is no activity for more than 5

System

on page 12 of

16

DI-206 ISDN Remote Router

As mentioned earlier, your first endeavor should be to increase the automatic
timeout. Enter the

System Information

window to do this. You will see this screen:

System Information

This menu contains administrative and system-related information.

The above parameters are described as follows:

• System Description –

• System Object ID –

This is the enterprise-specific MIB Object ID indicating this

type of router.

• System Up Time –

Shows how long the router has been running since the last

power off or reset.

• System Contact –

Enter the name of the department or individual responsible for

maintaining the router.

This is a non-changeable, short description of the product.

17

DI-206 ISDN Remote Router

• System Name –

Give the router a descriptive name for identification purposes.

• System Location –

• Console/Telnet Display Timeout in Minutes(0..90) –

to automatically logoff from the console menu after a given idle time. Enter a
timeout time between 0 and 90 minutes. Zero specifies no timeout.

• System MAC Address –

• ISDN Switch Type

that the DI-206 can communicate with. The DI-206 currently supports only the
DSS1 switch type.

Interface Configuration

The second item on the
is used to configure the LAN and ISDN interfaces:

Enter the geographic location of the router.

This is a security measure

The physical address of this router.

– The type of ISDN switch used by the telephone company

Main Menu

is the

Interface Configuration

screen, which

18

LAN

DI-206 ISDN Remote Router

The parameters are described below:

ISDN

• Description –

This is a user-defined, 32-character identifier used to name the

LAN.

• Operation Mode –

• State –

This is a toggle, to

The LAN port is 10BASE-T only.

Disable

or

Enable

the LAN interface.

The parameters are described below:

• Description –

This is a user-defined, 32-character identifier used to name the

ISDN.

19

DI-206 ISDN Remote Router

• Switch Type –

This parameter defines the type of ISDN service used. Currently,

the DI-206 only supports DSS-1 type ISDN lines.

• B1

and

B2 Channel Usage –

This defines whether the ISDN line is a leased line
or a normal switched line. If you are not using a leased line connection, set this
item to Switch.

• Country ID –

This field needs to contain the country parameter. Without this
information, the router cannot establish a connection. A list of country ID
numbers is located in Appendix E, “

• ISDN Data –

This field must contain the incoming telephone number for data

Country ID Numbers

.”

calls. In other words, it is your ISDN line’s data phone number.

• A/B Adapter 1

• Phone 1

and

and 2 – Enter the telephone numbers for your voice/analog lines.

2 Call Waiting

– If you have applied for and received call waiting
capabilities for your ISDN voice lines, you must enable these settings in order for
the call waiting feature to function.

There are 4 special operations for using call waiting (

flash

means a very brief
hanging up of the phone. In other words, for the first option below, flash 0, click
the hang up button on your phone very quickly and then press the number 0 on
your telephone’s keypad):

Flash 0 – disconnect the first phone call established.
Flash 1 – disconnect the second phone call established.
Flash 2 – switch between the two phone calls.
Flash 3 – speak to both parties simultaneously (if conference calling is enabled by

your phone company).

• POTS Lines

– [Plain Old Telephone Service]. Enables or disables phone calls on

the Phone 1 and Phone 2 jacks on the rear of the router.

• Global Reception

– When this is enabled, the Phone 1 and Phone 2 jacks will
receive all phone calls directed to them by the telephone company’s switch. When
disabled, the router will check incoming calls to the Phone 1 and 2 jacks against
the telephone numbers specified in the A/B Adapter 1 and 2 fields above.

• Block Outgoing CLID

– When this is enabled, your ISDN data phone number
and voice phone numbers will never be sent out when trying to establish a
connection. Thus, even if sites being called have Caller ID, they still won’t be
able to know your phone number.

• Inbound Authentication

– This defines the authorization protocol that will be
used when accepting a dial-in connection. The choices are Password
Authentication Protocol [

CHAP

[

] or

None

. PAP and CHAP do not provide a screen for users to manually

PAP

], Challenge Handshake Authentication Protocol

enter their Username and Password – instead, this data must be entered into the
dialing software before placing the call. Make sure the device dialing in is using

20

DI-206 ISDN Remote Router

the same protocol as defined here. The
wish dial-in users or networks to identify themselves or be subject to security.

• Call Bumping

– This setting only takes effect when both B channels are
connected and using multi-link PPP. If this is the case and call bumping is
enabled, when you receive an outgoing voice call, the second B channel will be
dropped (with all traffic being moved to the first B channel) and the voice call
will be received. If disabled, both B channels will continue their data
transmissions uninterrupted and the voice call will be ignored.

• State

– Enables or disables the ISDN port.

Network Configuration

IP protocol configuration and static routes are configured in the

Configuration

sub-menu. This menu is shown below:

None

setting may be used when you do not

Network

Select IP Configuration and the following screen opens:

21

DI-206 ISDN Remote Router

IP Stack Configuration

The network interface IP address, mask and protocols are specified in the

Configuration

submenus. The screens for both the LAN and ISDN interfaces are

shown below:

IP Stack

22

The parameters are described below:

DI-206 ISDN Remote Router

• IP Address –

This is the IP address for the router on the network to which this

interface is connected.

• Netmask –

This is a 32-bit bit mask that shows how the IP address is to be
divided into network, subnet and host parts. The netmask has ones in the bit
positions in the 32-bit address which are to be used for the network and subnet
parts, and zeros for the host part. The mask should contain at least the standard
network portion (as determined by the address's class), and the subnet field
should be contiguous with the network portion.

• Forwarding (LAN) –

This enables or disables communications between this

router and other router(s) on the LAN.

• State (ISDN) –

This is a link method between this interface and adjacent

router(s). The methods are described:

AUTO –

1.

This obtains and utilizes the IP address assignment from your ISP

(Internet Service Provider).

DISABLE –

2.

IP STACK –

3.
value of the parameter,

UNNUMBER –

4.

This disables this interface.

This enables this interface, and the IP address used will be the

IP Address

.

This utilizes a method of connecting this router with adjacent
routers, without having to define an IP network prefix between them. The
adjacent routers must have

UNNUMBER

capability too.

• RIP Routing Protocol –

This is a distance vector routing protocol. RIP is an
Internet standard Interior Gateway Protocol defined in RFC 1058 and RFC 1723.
Routing information is sent periodically (each 30 seconds, or triggered by
topology change) to an adjacent router. The adjacent router must be using the
same protocol. Setting this to

RIPV1&V2

will give the router the ability to make

routing information exchanges with any adjacent router.

23

DI-206 ISDN Remote Router

• RIP Routing Mode

– This parameter allows the router to specify the extent to

which it partakes in the RIP on this port. The options are described below:

None

1.

– The router will not participate in any RIP exchange with adjacent

routers.

Listen

2.

– The router will incorporate routing information from adjacent

routers, but will not send its own routing table.

Talk

3.

– The router will send adjacent routers its own routing table, but will

not incorporate routing information from them.

Both

4.

– The router will incorporate routing information from adjacent routers,

and will send adjacent routers it’s own routing table.

• IP Multicasting –

This feature enables or disables the router’s ability to route IP
Multicast packets from one interface to another (for example, from the LAN ports
to the ISDN port). IP Multicasting is a bandwidth-saving method for transmitting
data to more than one host. IP Multicasting is often used when sending/receiving
audio or video data. When IP Multicasting is enabled, the router will search its
multicast forwarding table and depending on the result of the search will either
forward the packet or add the group to the table. If IP Multicasting is disabled, all
multicast packets received by the router will be dropped, effectively limiting
multicasting to the LAN. The router can also perform DVMRP if this feature is
enabled (see Multicast Protocol below), which allows the DI-206 to share
multicast information with other routers, enabling IP multicasting over the ISDN
port.

• Multicast Protocol –

If this parameter is set to None, the router will only use the
Internet Group Management Protocol (IGMP), if IP Multicasting is enabled
above. This effectively limits multicast data to the local network. If set to
DVMRP (Distance Vector Multicast Routing Protocol), the router will also use
this protocol to share its multicast information with other routers (much like RIP),
in effect, enabling multicasting on the WAN (ISDN) port.

• IGMP Version –

Configures the router to use either IGMP version 1 or 2. A
major difference between the two is that version 2 allows the router to
communicate multicast information with other routers (via the ISDN port), even
if the other router isn’t using DVMRP.

• DHCP Client (LAN)

– This feature allows the LAN port to be assigned an IP
address from a DHCP server other than the one in the router. This feature should
be enabled only for special configurations (such as the presence of a cable modem
on the LAN) where you wish the router to work with a device on the network that
must act as a DHCP server. Otherwise, this feature should be kept disabled.

• RIP Spoofing (ISDN)

– This feature should only be enabled if you have more
than one router on your network and this router is providing your WAN
connection. In this case, if the WAN connection is dropped due to inactivity and
this feature is enabled, RIP packets will be sent to the other routers on the
network telling them that data can still be sent to the WAN via this router.
Otherwise, the other routers will learn that the WAN link has been disconnected
and will no longer forward packets destined for the WAN to this router, causing

24

IP Static Route

A static route is a permanent entry in the routing table. Static routing provides a
means of explicitly defining the next hop router for a particular destination network
IP address. Each static route entry also allows for a metric (a.k.a. hop count) to be
specified.

DI-206 ISDN Remote Router

the packets to be dropped before Bandwidth on Demand has a chance to
reestablish the WAN connection.

The parameters are described below:

• IP Address

depending on the netmask) and pairs it with a gateway.

• Netmask

– This mask shows how the destination IP address is to be divided into
network, subnet and host parts. The netmask has ones in the bit positions in the
32-bit address which are to be used for the network and subnet parts, and zeros
for the host part.

• Gateway

– This is the adjacent next hop router, for which the packets, arriving to
this router with this destination IP address, will be forwarded.

• Hops

– This is an associated RIP metric that may have its value set between 1
and 15, inclusive. A metric value higher than 15 (such as 16) means that the
network is unreachable.

• Intf

– This is the network interface containing the gateway that the packets will

be forwarded through.

• State

– This enables/disables a particular entry.

IP Static Route Examples

– This specifies the destination network IP address (or a host,

The IP Static Route Table shown in the

IP Static Route

screen above has the first

three entries configured for common implementations of static routing.

25

DI-206 ISDN Remote Router

The first entry assumes that ISDN1 has a connection to the Internet and defines the
default next hop router. If you use this router to connect to the Internet it is very
important that you create an entry here that defines the default next hop router as
your ISP. This configuration is also commonly used when RIP exchanges with other
Internet routers (on ISDN1) are disabled.

The second entry shows how to configure static routes when there is another router
on the LAN. The IP Address shown (202.12.125.0) is the network address for a
branch office, for example. The Gateway Address (210.172.23.1) is the IP address to
the LAN port on another router on the LAN that maintains an ISDN connection to
the branch office.

The third entry is an example of an enterprise ISDN connection (through telephone
lines) to another router, at a branch office for example. The IP Address is the
network address of the branch office. The Gateway Address is the IP Address of the
ISDN port on the branch office router. This configuration assumes there is a modem
on ISDN2 maintaining a dial-up connection to the branch office.

IP Networking

Under the

IP Configuration

connect or disconnect this router from the entire IP network.
When IP Networking is disabled, all routing functions are stopped. The only IP

Address the router will act on is its own, via Telnet for example.

Router Advertisement

When this option is enabled, the router will periodically send out ICMP packets that
announce itself on the network. These ICMP packets are utilized by the Windows 98
or later operating system, which will automatically update the default gateway
setting on the computer in which it is installed.

SNMP Agent Configuration

The Simple Network Management Protocol (SNMP), defined in STD 15, RFC 1157,
is a protocol governing the management and the monitoring of IP network devices
and their functions. The DI-206 supports the use of SNMP to acknowledge
communication between management stations and itself. Basically, the DI-206,
when connected to the network, acts as an SNMP agent, a software process that
responds to queries using SNMP to provide status and statistics about the router.

sub-menu, the IP Networking function can toggle to

Following is a description of how to configure the DI-206 for SNMP management.

26

DI-206 ISDN Remote Router

From the

Main Menu

SNMP Agent Configuration

SNMP Community Configuration

Select and enter the

SNMP Community Configuration

following configuration screen:

, select

SNMP Agent Configuration

menu, shown above.

. This will bring you to the

sub-menu. You will see the

The parameters are described below:

• SNMP Community String

– This community string is a user-defined identifying
name used to group together some arbitrary set of SNMP application entities
managed by the network manager.

• Access Right

– This element of the set {

Read Only, Read/Write

} is called the

SNMP access mode. If the SNMP Community String has an Access Right of

Read/Write
set

, and

Access Right is

, then that Community String is available as an operand for the

trap

operations. Otherwise, if the Community String’s corresponding

Read Only

, then it is available as an operand for the

get

operations only.

27

get

and

,

trap

DI-206 ISDN Remote Router

• Status

setting the string to

Invalid

– This validates or invalidates the use SNMP Community String, by

Valid

is the same as removing the string, however, the string remains so as to be

validated at an appropriate time.

SNMP Trap Manager Configuration

From the

Manager

SNMP Agent Configuration

sub-menu. You will see the following configuration screen:

or

Invalid

. Note that setting the use of the string to

menu, select and enter the

SNMP Trap

The parameters are described below:

• IP Address –

Management Station. The DI-206 router will send SNMP traps to these addresses.

• SNMP Community String –

name used to group together some arbitrary set of SNMP application entities
managed by the network manager. Traps will be sent to the IP Address (previous
parameter) as long as the corresponding Community String, in the Management
Station’s trap manager software, is the same.

• State –

This validates or invalidates the use of the SNMP Community String, by

setting the use of the string to

Invalid

is the same as removing the string, however, the string remains so as to be

validated again at an appropriate time.

SNMP Authenticated Trap

Returning to the
authentication failure trap message being sent to the Management Station by the
router. When an SNMP packet with an invalid community name is received, it will
be dropped. If this parameter is enabled, a trap will be sent to the network manager;
if this parameter is disabled, no trap will be sent.

Enter the IP address of the host who will act as an SNMP

The community string is a user-defined identifying

Valid

SNMP Agent Configuration

or

Invalid

. Note that setting the string to

menu, you can

Enable

or

Disable

an

28

Advanced Functions

DI-206 ISDN Remote Router

The

Advanced Functions

settings and is shown below:

Remote Access Configuration

The

Remote Access Configuration

dial-out connections over the ISDN line. An ISDN line has a D channel for
establishing connections and two B (Bearer) channels, which transmit and receive
the actual signals, whether voice or data. The two B channels can support two
independent remote connections or be banded together using Multi-link PPP to
implement Bandwidth on Demand (configured separately in the

Configuration

menu, the last item in the

menu contains most of the more complex configuration

menu is used to set up the router for dial-in and

Multi-Link PPP

Advanced Functions

window).

The B-Channels can also carry voice and fax calls, which are routed to the telephone
jacks located on the rear of the router. Please note, however, that the DI-206 can
maintain only two connections at a time via the two B channels, whether the
connections are voice, data, dial-in users, remote networks or a combination thereof.

Remote Operation Overview

The DI-206 is very flexible and can be configured for a variety of remote
connections. Since configuring the router can be quite complex - depending on the
number and type of remote connection(s) you wish to implement – we have
described some of the basic functions and procedures below.

Dial-In User Connections

Dial-in users are defined as a single user on a computer, such as a person working at
home, who dials into the office to use network resources. In almost all cases, a Dial­In User Profile needs to be set up for each user who will dial in to the router so the
router can tailor the connection for each user. Once this is done, the remote user will

29

DI-206 ISDN Remote Router

be able to use network resources as if he were connected locally. When the user dials
into the DI-206, the call comes into the D-channel and after answering the phone, the
DI-206:

1. Identifies the Username and Password using the authentication protocol defined in the

Configuration, ISDN

enter it into his dialing software before dialing.

2. Checks the Username and Password against those defined in the Dial-In User Profiles and
Remote Network Profiles.

3. Assuming a matching Dial-In User Profile is found, the router may configure the IP a ddress of
the remote station (as defined in the Dial-In User Profile).

4. Configures a dial-in Interface (a virtual circuit) to handle the connection.

5. Establishes the connection on whichever B-channel (p hysical port) is open by mapping the di al-in
interface to that port.

6. In the case where the Dial-In User does not need to supply a Username and Password (Auth Type
is set to
IP address.

None

in the

submenu. The dial-in user is not prompted for this information, but must

Interface Configuration

Remote Network Connections

Remote networks are defined as other networks (LANs) that have WAN connections
using a router, Internet server, network modem or similar device (in this document
however, we will assume the remote device is a router). In almost all cases, a
Remote Network Profile needs to be set up for each network that will connect to the
DI-206 via the ISDN lines. The Remote Network Profiles are necessary for the
router to identify and tailor the connection to the remote network’s router. Once this
is done, a connection between the two routers can be made and computers on each
network can communicate with each other.

Interface

submenu) the remote computer must have its own

Dial-In Network Connections

A dial-in network connection is very similar to a dial-in user connection. When the
remote router dials into the DI-206, the call comes into the D-channel and after
answering the phone, the DI-206:

1. Identifies the Username and Password using the authentication protocol defined in the

Configuration, ISDN

2. Checks the Username and Password against those defined in the Dial-In User Profiles and
Remote Network Profiles.

3. Assuming a matching Remote Network P rofile is found, the router may configur e the IP add ress
of the remote station (as defined in the Remote Network Profile).

4. Configures the specified
defined in the
connection.

5. Establishes the connection on whichever B-channel (p hysical port) is open by mapping the di al-in
interface to that port.

Interface Configuration

submenu.

ISDN Interface

(a virtual circuit) using the co nfiguration par ameters

menu and the Remote Network Profile to handle the

Dial-Out Network Connections

Interface

Dial-out network connections are much different than dial-in connections.
When a packet on the LAN reaches the router, the DI-206 will:

30

DI-206 ISDN Remote Router

1. Check its routing table to try to identify where this packet should go. It looks for two variables in
the routing table, Gateway address and Interface. There are four possible results:
I. In the case where the destination resides in the same IP network on the LAN, the routing

engine never acts on the packet and it is sent directly to the destination through the built-in
hub.

II. In the case where the destination resides on a different IP network on the LAN (which can

happen when Multiple Home Configuration is set up), the router will send out an ARP
request to obtain the MAC address of the destination computer (or router) and deliver the
packet. Note that defining Static ARPs can speed up delivery since the router won’t need to
send out an ARP request.

III. In the case where the router finds a match in the routing table (which includes IP Static

Routes), it uses the Gateway address and Interface numbers to identify the correct Remote
Network Profile to use to dial out. From the Remote Network Profile, the router gets the
telephone number and other information and dials out, establishes a connection and delivers
the packet. If you have a connection to the Internet, it is very important that you define the
default next hop router in the
(see the
This is because if a user on your LAN makes a request to download a web page for the first
time, for instance, since it is the first time, the DI-206 will not have any record of the web
page’s IP address. If no default next hop router is defined, the request will be dropped and
the user will get a ‘Destination Unreachable’ error message. However, if a default next hop
router is defined in the IP Static Routes, the DI-206 will pass this request on to the ISP (the
request will go through) and the user will receive the web page.

IP Static Routes

IP Static Routes

section of this manual for more detailed configuration information).

submenu of the console program as your ISP

IV. In the case where there is no match for the destination IP address in the routing table, and no

default next hop router is defined, the packet will be dropped and no action will be taken.

The

Remote Access Configuration

submenu is shown below. All items in the

submenu are described as follows.

31

DI-206 ISDN Remote Router

Dial Configuration

You can configure the two ISDN interfaces on your DI-206 to dial-out only when a
packet is forwarded to that interface, and hang up after all data has been transferred
and the link is idle. This can be used to lower the cost of an unpopular link or used
as a backup link to your ISP. This feature is commonly called “Dial on Demand”.
ISDN interfaces can also be configured here to receive calls from dial in users and
other networks, called “Remote Access”. Please note however, that in all cases, after
configuring the ISDN Links in the
further configured in the
submenu.

Dial Configuration

Dial-In User Profile

submenu, they must be

submenu or

Remote Network Profile

Dial In IP Pool

The dial in IP pool allows you to define a range of IP addresses that will be reserved
for and assigned to dial-in users.

The items are described as follows:

32

DI-206 ISDN Remote Router

• IP Address

• Range

ISDN Link 1

This submenu contains a number of settings (shown below) which allow you to
configure the router to dial out.

– This is the first IP Address that will be assigned to a dial-in user.

– This is the number of IP Addresses that can be assigned. In the window

shown above, dial-in users will be assigned the IP Addresses 170.100.200.1 or

170.100.200.2 (only two are necessary since the router used in the examples has
only two ISDN ports).

The parameters are described below:

• Dial Retry Time –

next dial attempt.

• Dial Retry Count –

router will make when trying to establish a connection on this interface.

• Call Back Delay –

remote user is called back.

Dial-In User Profile

The Dial-In User Profile is used to configure the DI-206 for single users (for
example a person working at home) to dial in to the router and gain access to the
network. At least one User Profile must be configured for each user who will dial in
(in conjunction with Dial Configuration settings). Please note that WAN connections
to computers on other networks must be defined in the
submenu.

Up to eight users can be set up to dial in to the router. However, more dial-in users
can be accommodated by using a Radius server as described in the

This is the time (in seconds) the router will wait before the

This is the specified maximum number of dial attempts the

This is the time (in seconds) the router will wait before a

Remote Network Profile

Radius

33

DI-206 ISDN Remote Router

Configuration

section of this manual. Please note that when a Radius server is being

used, the Dial-in User Profiles will be disabled.
The

Dial-In User Profile

submenu appears below:

Select a dial-in user from the screen above.

The parameters in the above window are described as follows:

• Name –

The maximum length is 64 characters. This username is for password
challenges (authentication). The user dialing in must supply this username in
order to be allowed access to the router.

• Password –

• Rem CLID

This is the password associated with the above Name field.

– Remote Caller ID. This is the telephone number of the Remote
User and is used for security. When a phone number is entered in this field, the
router will make sure that the incoming call is coming from the same phone
number as the one defined here. In other words, the remote user can only be

34

DI-206 ISDN Remote Router

calling from the telephone number defined here, otherwise the call will not be
accepted. This function is disabled if the field is left blank.

• Default IP –

This is the IP address that will be assigned to the dial-in user when
the IP Address Supply setting below is set to Default. Assigning an IP address to
the remote computer ensures that the IP address does not clash with other IP
addresses on your network.

• IP Address Supply –

This field defines how the remote user will obtain an IP

address. The choices include:

Default
Dynamic
None

• Call Back –

– Uses the Default IP address defined above,

- Taken from the Dial In IP pool, or

- The remote user supplies his own IP Address.
This field determines if the router will allow call back to the Remote

Dial-In User upon dial-in. If this option is enabled, the router will be able to call
back to the Remote Dial-In User if they request it. In such a case, the router will
disconnect the initial call from this user and dial back to the specified call back
number. The default is no call back.

• Phone Number Supplied by –

Router

• Phone Number –

If

is selected above, then this phone number is usually

Toggle between

Router

provided by the person who initially set up the router. If

and

Caller

Caller

.

is selected, you

must enter the phone number that will be called back yourself.

• Idle Time –

packets have gone through the router. This setting will trigger the router to
disconnect this interface when it is reached.

• State –

Enables or disables this User Profile.

Remote Network Profile

The Remote Network Profile is used to configure the router for ISDN connections to
other networks. In practice, the DI-206 will either dial-out to or receive incoming
calls from another router, the ‘gateway’ to the other network.

This is the elapsed time (in seconds) since the last valid or active

35

DI-206 ISDN Remote Router

Select the desired entry from the screen above:

The parameters in the above window are described as follows:

• Remote Name

– Name for the remote network that the DI-206 is being set up to

connect with.

• Direction –

Dial-[In], dial-[

Out

], or [

Both

]. This field defines whether the router
on the other network will dial-[In] to the DI-206 to establish a connection, the DI­206 will dial-[

Both

[

] ways.

Out

] to the other network, or a connection can be established

When this is set to In, the DI-206 will only establish a connection with the other
network by receiving calls on the ISDN port specified in the Interface field below.
Also, the incoming calls will be subject to the Name, Password and Rem CLID
fields in the Incoming section below.

36

DI-206 ISDN Remote Router

When this is set to

Out

, the router will only make calls on the ISDN interface
specified in the Interface field below. Also, the outgoing calls will be subject to
the Name, Password and Phone Number fields in the Outgoing section below.

When set to

Both

, the dial in and dial out conditions described above will both be

observed.

• Interface

– ISDN Link 1 [

ISDN L1

] or ISDN Link 2 [

ISDN L2

]. This field is
used to assign a remote network to a logical (virtual) interface called a virtual
circuit. More than one remote network can be configured to use the same
interface, but they cannot be connected at the same time. Thus, if you wish to
have two WAN connections operate simultaneously, make sure they are
configured on different interfaces. On the other hand, if you have two dial-out
remote network profiles but wish to keep one line always open for dial-in users,
make sure the two dial-out profiles use the same interface. In this case, the two
profiles will share the same interface; the second one using it after the first one’s
idle time has expired and it has relinquished it.

• Phone -

This is the telephone number that will be dialed to make the outgoing

connection.

• Idle Time –

This is the elapsed time (in seconds), of inactivity, that will trigger

the router to disconnect this interface.

• Set Peer IP as Default Gateway –

When enabled, this feature sets the IP address
of the remote device as the default gateway (default next hop router) for all
packets not found in the routing table. This option should be enabled for the
ISDN circuit (ISDN1 or ISDN2) that is used to connect to the Internet. Also, if
the Peer IP is set as the default gateway here, you still need to define a static
default route in the

Network Configuration, IP Static Route

submenu, but you
don’t need to designate a gateway IP address for the static route (the routers will
automatically negotiate and adjust the gateway IP setting accordingly). And also
make sure that the Remote IP Address in the

Remote Networks Profile

is set to

0.0.0.0. Note that only one ISDN circuit should be connected to the Internet, and
only one ISDN circuit (the same one) should be the default gateway.

• Incoming

• Name

– The maximum length is 64 characters. This username is for
password challenges (authentication). The user dialing in must supply this
username in order to be allowed access to the router.

• Password

• Rem CLID

– This is the password associated with the above Name field.

– Remote Caller ID. This is the telephone number of the Remote
User and is used for security. When a phone number is entered in this field,
the router will make sure that the incoming call is coming from the same
phone number as the one defined here. In other words, the remote user can
only be calling from the telephone number defined here, otherwise the call
will not be accepted. This function is disabled if the field is left blank.

• Call Back

– This field determines whether the router calls back after

receiving a call from this Remote Network Profile. If this option is enabled,

37

DI-206 ISDN Remote Router

• Outgoing

the router will disconnect the initial call and call back to the phone number
that you provide. Note that this field will be valid only if the Direction setting
above is

Both

.

• Name

– The maximum length is 64 characters. Spaces and punctuation are
not usually accepted. This username is for password challenges
(authentication) which are automatically handled by the router when dialing
out. The DI-206 will use PAP and CHAP (whichever works) to make the
connection.

• Password

• Remote IP Address

– This is the password associated with the above Name field.

– This is the IP address that will be assigned to the dial-in
network when the IP Address Supply setting below is set to Default. Assigning an
IP address to the router dialing in ensures that the IP address does not clash with
other IP addresses on your network. For dial out connections utilizing dial on
demand, the IP address of the remote router needs to be entered here so the router
knows which remote network to establish a connection with to deliver the packet.

• IP Address Supply

– This field defines how the router will assign an IP address

to a device dialing in. The choices include:

Default
Dynamic
None

• Multi-Link PPP

– Uses the Remote IP address defined above,

- Taken from the Dial In IP pool, or

- The remote user supplies their own IP Address.
– Enables/disables multi-link PPP on this port. Individual ISDN

ports can be set to join the MLPPP bundle by enabling Multi-Link on each port.
When enabled, the port will join the MLPPP bundle. Please note that the DI-206
contains only one MLPPP bundle. All ports taking part in MLPPP, even the first
or primary port which initially establishes the connection, must have Multi-Link
enabled. The ISDN port that first established the connection is the Primary ISDN
Port and will not disconnect due to a BOD Low Threshold event, but is subject to
Dial on Demand (DOD) settings.

• Compression

standard using a 4:1 compression scheme. When enabled, the router will try to
use Stac compression on the designated ISDN port whenever possible. If the
destination device is not capable of using Stac compression, the two devices will
still communicate, albeit without using Stac compression. When disabled, Stac
compression will never be used on this port.

• State

Select Connect Test at the bottom of the screen to test if your setup is correct.

DHCP Configuration

The DI-206 Router implements the Dynamic Host Configuration Protocol (DHCP),
which allows the entire IP network to be centrally managed by the router. It does this
by assigning IP addresses and configuration parameters to hosts as they are powered

– Enables or disables Stac compression. This is an industry

– Enables or disables this Remote Network Profile.

38

DI-206 ISDN Remote Router

on and come onto the network. This can be a great help for network administration
since many administrative tasks such as keeping track of each computer’s IP address
are handled by the router. The DI-206 can implement DHCP in one of the two ways
shown below:

DHCP Server Configuration

When acting as a DHCP server, the DI-206 will manage many of the IP network
parameters. The DI-206 will never assign a broadcast or network IP addresses to
hosts, even if such an address is included in the specified range. The following is the

DHCP Server Configuration

screen:

Dynamic IP Pool

The
can set on the hosts. Please note that the Dynamic IP Pool cannot be enabled when
the DHCP Agent feature is enabled.

Dynamic IP Pool

screen shown below contains the parameters that the router

39

DI-206 ISDN Remote Router

The parameters are described below:

• IP Address –

This is the base (starting) address for the IP pool of IP addresses to

be assigned.

• Range –

This is the range of contiguous, IP addresses, above the base IP Address
above. In the above example, the IP addresses assigned host computers as they
come onto the network would be 202.93.47.1, 202.93.47.2 … 202.93.47.100.

• Netmask –

This mask informs the client, how the destination IP address is to be
divided into network, subnet and host parts. The netmask has ones in the bit
positions in the 32-bit address which are to be used for the network and subnet
parts, and zeros for the host part.

• Gateway –

This specifies the Gateway IP Address that will be assigned to and
used by the DHCP clients.

• Lease Time –

This specifies the number of hours a client can lease an IP address,
from the dynamically allocated IP pool. The maximum value is 65535 and a
value of 0 means the lease is permanent.

• DNS IP –

This specifies the Domain Name System server, used by the DHCP
clients using leased IP addresses, to translate hostnames into IP addresses or vice­versa.

• WINS IP –

This specifies the IP address of the Windows Internet Naming
Service server. This server has software that resolves NetBIOS names to IP
addresses.

• Domain Name –

This is the common suffix, shared by networked hosts, used to

represent a common network domain.

• State –

This enables or disables the dynamic IP Pool function.

40

Static IP Pool

DI-206 ISDN Remote Router

The Static IP Pool configuration functions in much the same way as the Dynamic IP
Pool configuration. The only difference is that a particular IP address can be
assigned to a particular host. This is used for hosts such as servers that need to have
static IP addresses to function properly or to make them accessible to remote users.
The host is identified by the MAC address of its NIC, which must be entered on this
screen.

Select an entry from the screen above and press <Enter>. The following screen
appears:

The parameters above are described below:

• IP Address –

This is the static IP address to be assigned.

• MAC Address –

This specifies the physical address of the particular host that

will receive the above IP address.

41

DI-206 ISDN Remote Router

All other parameters (Netmask, Gateway, DNS IP, WINS IP, State, & Domain
Name) are identical to those in

DHCP Relay Agent

The DHCP Relay Agent feature allows the DI-206 to act as a go-between for a
remote DHCP server assigning IP addresses to local clients. This can be useful if
you wish to have all IP addresses in your company, including those in branch offices,
assigned from a DHCP server centrally located at your headquarters, for example.

Dynamic IP Pool

screen in the previous section.

Items are described as follows:

• DHCP Server IP Address –

When a local computer powers up and sends a DHCP request for an IP address,
the DI-206 will forward the request to the address specified here.

• Time Threshold –

since the host began requesting an IP address. If the value define here is
exceeded, the relay agent will not pass along the request from the host.

• State

Filter Configuration

Your DI-206 uses filters (configurable at two layers) to screen packet data, and apply
a routing decision. There are two methods for configuring filters: you can configure
a filter at the network layer (IP filter) to restrict access between networks and reduce
unnecessary internetwork traffic; and you can configure a filter at the data-link layer
(a general filter) to provide a protocol independent filter.

Good knowledge of network protocols is required to configure a specific filter
appropriately. It is important for the router to operate correctly, therefore, necessary
packets must be allowed to pass through the filters. In other words, do not attempt to
configure filters on a utilized router unless you understand what you are doing.

This is the IP address of the remote DHCP server.

This specifies the maximum amount of time (in seconds)

– Enables or disables the DHCP Relay Agent function.

The following section describes how to configure the router filter parameters.

42

Configuring a Filter Set

DI-206 ISDN Remote Router

Under the

Advanced Functions

menu, select

Filter Configuration

following screen:

The three sub-menus are described as follows:

• Filter State of Interface

– This is used to choose the default, routing decisions

for packets, not meeting the criteria for specific filters.

. You will see the

• Layer 2 Filter

Foreknowledge of the specific protocol, used on the interface (LAN or WANs), is
needed to make effective use of this filter.

• IP Filter

things, prohibit specific packets from entering the LAN. Alternatively, you can
set up filters that allow certain types of IP packets to enter the LAN.

Filter State of Interface

The

Filter State of Interface

have not met the corresponding criteria, to forward or drop packets.

– This is a data-link layer (protocol independent) filter.

– This is an IP protocol specific filter, allowing you to, among other

sub-menu lets you disable a filter, or, for packets that

43

DI-206 ISDN Remote Router

Each decision on handling packets is described below:

Layer 2 Filter

1.

2.

Disable
Forward

Will not apply a filter.

–

This allows the routing of a packet, even though it has not met the

–

criteria of the corresponding filter.

3.

Drop

This drops (doesn’t allow routing for) a packet that has not met the

–

criteria for the corresponding filter.

The

Layer 2 Filter

sub-menu contains a protocol independent (data-link layer) filter.
Foreknowledge of the specific protocol used on the interface (LAN or WANs) is
needed to make effective use of this filter.

Select an entry above and then press <Enter>. The following screen appears:

44

The parameters of a filter are described below:

DI-206 ISDN Remote Router

• Name –

This is a 12 character (maximum), alphanumeric, user-defined name,

used to identify the filter.

• Direction –

This defines the direction of the frame relative to the Interface

parameter below.

• State –

This is used to choose the routing decision applied to the frame. The three

decisions are described:

1. forward

This allows the routing of the frame, if it has met the criteria of the

–

corresponding filter.

2. drop –

This drops (doesn’t allow routing for) a specific frame that has met

the criteria of the corresponding filter.

3. disable –

• Interface –

This does not apply the protocol independent filter.

This applies the filter to a specific interface, either LAN or one of the

ISDN interfaces.

• Offset –

This defines the reference byte for the Length parameter (described
below). The Offset is the number of bytes (octets) from the beginning of the first
byte of the frame header, immediately after the preamble. The range of the offset
parameter is from 0 to 255 octets. The first byte in a packet has an offset 0.

IP Filter

• Length –

This is the number of bytes (octets) from 0 to 8 to compare from the

offset value (the Offset reference byte).

• Value –

This is a 16 digit, hexadecimal field, defining the actual bit values used

to compare with the frame data, at the specified (Offset) position.

• Mask –

This is a 16 digit, hexadecimal bit mask, used as an operand in the bit-

wise AND operation that will be applied to the Value parameter.

The IP Filter is specifically an IP protocols filter, allowing you to, among other
things, firewall your network, prohibiting specific packets from entering or going out

45

DI-206 ISDN Remote Router

from your network. It is necessary to have good knowledge of IP protocol before
effectively configuring this filter.

Select an entry above and then press <Enter>. The following screen appears:

The IP Filter parameters are described below:

• Name –

This is a 12 character (maximum), alphanumeric, user-defined name,

used to identify the filter.

• Direction –

This defines the direction of the packet relative to the Interface

parameter below.

• State –

This is used to define the routing decision applied to the packet. The three

routing decisions are described:

1. forward

This allows the routing of the packet, if it has met the criteria of

–

the corresponding filter.

46

DI-206 ISDN Remote Router

2. drop –

This drops (doesn’t allow routing for) a specific packet that has met

the criteria of the corresponding filter.

3. disable –

• Interface –

This does not apply the IP filter.

This applies the filter to a specific interface, LAN or one of the ISDN

interfaces.

• Protocol Type –

This is a protocol identifier, as assigned by the Internet
Assigned Numbers Authority (IANA). The values of this identifier are described
in RFC-1700. This router supports the following:

1

– This is Internet Control Message (ICMP), defined in RFC 792.

6

– This is Transmission Control (TCP), defined in RFC 793.

17

– This is User Datagram (UDP), defined in RFC 798.

• Src IP –

• Src Netmask –

This is the source address in the IP header of this packet.

This mask is bit-wise AND’d with the source IP address and bit­wise AND’d with the IP address of the incoming interface. The two results are
then compared.

• Src Port –

This is the source port , in the TCP or UDP header, of the packet.

• Src Port Operation –

Src Port

(the

• Dst IP –

parameter) value, of the TCP or UDP header.

This is the destination address in the IP header of the packet.

• Dst Netmask –

bit-wise AND’d with the IP address of the incoming interface. The two results are
then compared.

• Dst Port –

This is the destination port, in the TCP or UDP header, of the packet.

• Dst Port Operation –

port (the

• ICMP Type –

Dst Port

This is the type field, in the ICMP header, used to identify a

particular ICMP message.

• ICMP Code –

This is the code field, in the ICMP header, used to further specify

the ICMP type.

• TCP Flag –

This is a hex number, representing the six flag bits in the TCP

header. The value range is from 0 to 3F.

Multiple Home Configuration

This comparison operation is applied to the source port

This mask is bit-wise AND’d with the destination IP address and

This comparison operation is applied to the destination

parameter) value, of the TCP or UDP header.

Besides the IP address assigned to the LAN interface in the

Network Configuration

menu, the LAN may have up to 3 additional IP interfaces. These additional IP
interfaces are referred to as MIP1 to MIP3. This type of configuration is known as a
multiple home configuration.

47

DI-206 ISDN Remote Router

Multiple Home can be demonstrated by this example:
A company has 625 users (computers) all connected to one physical network using

Ethernet. However, the company only has one Class C IP network address,

202.100.160.0. This network address will only support 254 users. To solve the
shortage of IP address problem and to plan for future growth, the company applies
for and receives two more Class C IP network addresses, 203.101.161.0 and

204.102.162.0. This gives the company a total of 254 x 3 = 762 IP Addresses, which
it assigns to the computer users, with a few left over for future needs. Due to the
nature of IP networks, however, the users in one IP network domain (202.100.160.0,
for example) cannot communicate with users on a different IP domain
(203.101.161.0). Multiple home solves this problem. When you register the
additional IP network addresses in the Multiple Home Configuration menu on the
router, the router will route data between the three IP networks using the single
LAN.

In this router, multiple home configurations only apply to the LAN interface.

48

The parameters are described below:

DI-206 ISDN Remote Router

Static ARP

• IP Address

• Routing Protocol

– This is a network IP address of a separate IP network on the LAN.

– This is the same as in the

Network Configuration

screen
section. Keep in mind that these exchanges are made with adjacent routers on the
LAN, if present.

• IP Multicasting

– This enables/disables IP multicasting on the IP network you

are defining.

All other parameters (Netmask, Routing Mode, Multicast Protocol and IGMP
Version) are identical to those in the

Configuration, ISDN

screen section.

Network Configuration, IP Stack

This special function is intended to speed up the process of finding a host's Ethernet
(MAC) address from its network address, and provides a special condition – any
other host acting as an impostor by using the same IP address as the legitimate host,
will be ignored by this router.

Basically, when a packet comes into the router from the ISDN line and is destined
for a host on the LAN, the router will use information defined here to immediately
send the packet to the host rather than send out an ARP request to find the host’s
MAC address.

Select an entry above and then press <Enter>. The following screen appears:

49

DI-206 ISDN Remote Router

The parameters are described as follows:

• IP Address –

for.

• MAC Address –

owner of the IP address.

• State –

NAT Configuration

Network Address Translation (NAT) is a routing protocol that allows your network
to become a
does this by changing the IP address of packets from a
the Internet to a
Internet) and vice versa.

NAT has two major benefits. First, NAT allows many users to access the Internet
using a small number or even a single global IP address. This can greatly reduce the
costs associated with Internet access and also helps alleviate the current shortage of
Internet IP addresses. Secondly, the NAT process creates a firewall which hides your
local network from Internet users, providing a degree of security to your Internet
connection.

This is the IP address of the host you wish to define a static ARP

This is the physical address of the host that is the authorized

This toggles enable and disable.

private

network that is isolated from, yet connected to the Internet. It

local

IP address usable on your private network (but not on the

global

IP address usable on

To be successfully implemented, NAT should be used only when the majority of
network traffic remains on the local network. In cases where a large percentage of
network traffic is destined for the Internet, NAT can adversely affect the speed and
performance of your Internet connection. Also, your network servers such as ftp
servers, web servers or mail servers will probably need to be assigned

static

NAT IP
addresses so their IP addresses remain consistent. This issue will be further
discussed later.

50

Network Address Port Translation (NAPT) is a subset of NAT where many local IP
addresses and their TCP/UDP port numbers are translated to a single global IP
address and it’s TCP/UDP port number. In this document, the term NAT will refer to
both NAT and NAPT unless otherwise stated.

NAT can work in conjunction with DHCP. Thus, if both are enabled and properly
configured, the DHCP server in the DI-206 will assign local IP addresses to
computers on your network.

How NAT Works

In the most common NAT configuration, your network uses local IP addresses that
are not valid on the Internet. Internet (global) IP addresses are unique, with no two
devices have the same IP address. The local IP addresses can be freely assigned to
computers on your network by your network administrator (within guidelines
defined later in this chapter and in Appendix B,
manually or by using DHCP. The ISDN port on the router is assigned a globally
unique IP Address that IS valid on the Internet, since it will be sending and receiving
data directly to the Internet and is therefore part of it. Please study the example
diagram below carefully.

“IP Concepts”

DI-206 ISDN Remote Router

). This can be done

Single

Global

IP Address

176.220.22.1

ISDN

Router

192.168.100.2

Port

NAT

Translator

LAN
Port

Local IP

192.168.100.1

192.168.100.3

WAN

192.168.100.4

LAN

192.168.100.5

Please note that in the above diagram, the Gateway IP address settings for the local
PC’s needs to be set to 192.168.100.1, the LAN IP address of the router.

NAT manipulates the IP addresses in packet headers on a one-to-one basis. An
outgoing data packet (a packet originating from a computer on the local LAN and
destined for a computer outside the private network) will have its IP address
translated as shown below.

51

DI-206 ISDN Remote Router

In the Outgoing Data Packet above, the
translated by NAT. The

Destination IP Address

outside the private network, on the Internet for example. And the

Source IP address

is the IP address of a computer

is the IP address that is

Data

portion of the
packet is the information payload borne by the packet, for instance a request to view
a web page.

The router logs the changes made to the IP header in its NAT table. The NAT table
enables the router to send replies back to the local computer as shown below.

In the Inbound Data Packet above, the
is translated by NAT. The
the private network. And the

Source IP Address

Data

Destination IP Address

is the IP address that

is the IP address of a computer outside

portion of the packet is the information payload

borne by the packet, for example, the contents of a web page.
The actual information in the NAT table depends whether the router is implementing

NAT or NAPT.

NAT

This section discusses the NAT protocol as opposed to NAPT, which is discussed in
the next section.

NAT is the initial protocol set forth by RFC 1631 and provides a means in which
private networks can communicate with the Internet by using a small number of IP
addresses. In our discussion, we will use the example IP addresses listed in the table
below and the network diagram shown on page 51.

Global IP Addresses
(for use with NAT)

200.100.50.1 192.168.100.2

200.100.50.2 192.168.100.3

200.100.50.3 192.168.100.4

200.100.50.4 192.168.100.5

200.100.50.5 192.168.100.6

Local IP Addresses
(assigned to computers
on the local network)

192.168.100.7

192.168.100.8

192.168.100.9

192.168.100.10

52

DI-206 ISDN Remote Router

Please note that in the above table there are 9 users on the local network using 5
global IP addresses to access the Internet.

When a packet on the local network arrives at the router and needs to be sent to the
Internet, NAT will change the source IP address (for example 192.168.100.2) to a
global address (200.100.50.1, for example). If this packet generates a reply (as for
example, a request to view a web page will), NAT will change the destination IP
address on the reply packet back to the local IP address for delivery to the machine
on the local (stub) network.

The difference between static and dynamic NAT is that once the five global
addresses are manually assigned when using static NAT, they will never change. The
only way to change them is by using the console program to manually reassign them.
When using dynamic NAT, the router will map a local IP address to a global IP
address whenever a request is made. Since there are only 5 global IP addresses in the
example above, there can only be 5 mappings at any one time. In other words, much
like static NAT, only 5 local machines can access the Internet at any one time.
However, contrary to static NAT, the router will discard the mapping between the
global and local IP addresses after a certain length of time (which is quite long so
rarely happens), or after the session is finished (an example of a session is when
requesting a web page, the entire page has completed downloading). The most
common implementation of NAT is to define a range of dynamic addresses to be
used by hosts, but assign static addresses to your servers if you wish for them to be
accessible from outside your network.

Setting Local IP Addresses

When implementing NAT and thus creating a private network that is isolated from
the Internet, you can assign any IP addresses to host computers without problems.
However, the Internet Assigned Numbers Authority (IANA) has reserved the
following three blocks of IP Addresses specifically for private networks:

It is recommended that you choose local IP addresses for use with NAT from the
private network IP addresses in the above list. For more information on address
assignment, refer to RFC 1597,
1466,

Guidelines for Management of IP Address Space

Class Beginning Address Ending Address

A 10.0.0.0 10.255.255.255
B 172.16.0.0 172.31.255.255
C 192.168.0.0 192.168.255.255

Address Allocation for Private Internets

.

and RFC

53

DI-206 ISDN Remote Router

Configure NAT/NAPT

The first screen shows the complete NAT table that is defined by the network
manager:

For any NAT entry, you must configure two different screens. The first one is
accessible by positioning the cursor over the name field and hitting <Enter> (in the
window shown above, this corresponds to the field ‘Branch1’). After configuring the
NAT options in the Name field, you must save the changes, EXIT, and position the
cursor over the NAT IP Pool to configure variables there.

Name Field Configuration Screen

The configuration screen for the name field appears as follows:

54

The parameters are described as follows:

DI-206 ISDN Remote Router

• Name –

This is a 12 character, alphanumeric, user-defined name, used to identify

the network address translation.

• Global Interface –

This is the interface corresponding to the Global IP and
Range parameters, in the NAT table, to form unique IP address[es], known to the
outside (regional or Internet) routers, on this interface.

• Local Interface –

This is the interface corresponding to the Local IP and Range
parameters, in the NAT table, to form local IP address[es], known only to this
interface and the network within.

• Translation Mode –

Static NAT –

This offers four types of NATs.

Maps one global IP address to one local IP address. After all
global IP addresses are assigned, they will remain static. This option may be
necessary for email, web, ftp servers, etc. where static IP addresses are
essential for operation.

Dynamic NAT –

Maps one global IP address to one local IP address. Global
IP addresses will be dynamically reassigned to different local IP addresses if
not currently being used. This allows a larger number of users to use a small
number of IP addresses.

Static NAPT –

One to one mapping of UDP/TCP port numbers to let
packets with specific UDP/TCP port numbers enter the local IP domain. The
NAPT map table will not age. This option may be necessary for email, web,
ftp servers, etc. where static port numbers are essential for operation. Setting
the global port number to 0 opens port numbers 1024 to 65535 for the
designated local IP address, creating a

visible computer

. This allows a
computer to be freely accessed by other computers on the Internet, which is
necessary for some applications to function correctly when using NAPT,
including Microsoft NetMeeting, CUSeeMe, etc.

55

DI-206 ISDN Remote Router

Dynamic NAPT -

NAPT map table will age. This option allows many hosts to use a single,
globally unique IP address, and thus will only be used on outbound packets.

• State –

NAT IP Pool Configuration Screen

Enables or disables this NAT configuration.

Now you must select, enter, and configure the NAT IP Pool from the

Configuration

sub-menu, shown below.

Dynamic NAT

This screen (below) is how the NAT IP Pool appears, if Dynamic NAT was chosen
for the Translation Mode parameter. Each entry, in this configuration, can be used to
map multiple, contiguous global addresses and local addresses to each other.

One to one mapping of UDP/TCP port numbers. The

NAT

The parameters are described below:

• Global IP –

An IP Address that is globally unique and valid on the Internet. It is
the base, global address for the global addresses that will be recognized by the
interface in the Global Interface parameter.

• Range –

This is the range of contiguous, global addresses above (and including)

the base Global IP.

• Local IP –

An IP Address that is only used in the stub domain since it is not
unique. It is the base, local address for the local addresses that will be recognized
by the interface in the Local Interface parameter.

• Range –

This is the range of contiguous local addresses above (and including) the

base Local IP.

• State –

This toggles enable/disable for this NAT entry.

56

Dynamic NAPT

This screen (below) is how the NAT IP Pool appears, if Dynamic NAPT was chosen
for the Translation Mode parameter. Each entry, in this configuration, can be used to
map a single global address and multiple, contiguous local addresses to each other.

DI-206 ISDN Remote Router

Static NAT

All of the parameters are the same as in Dynamic NAT, except the Global IP is a
solitary, global address.

• Global IP

– This is a single, globally unique IP Address of the global interface
(the interface to which it is assigned, in this case, one of the ISDN interfaces) that
is valid on the Internet.

This screen (below) is how the NAT IP Pool appears, if Static NAT was chosen for
the Translation Mode parameter. Each entry in this configuration is used to map a
single global IP address a single local IP address.

57

DI-206 ISDN Remote Router

The parameters are described as follows:

Static NAPT

• Global IP

– This is a single, global IP Address that is valid on the Internet, or on
the same subnet of the global interface.

• Local IP

• State

– This is a single, local IP Address that is not valid on the Internet.

– Enables or disables this entry.

This screen (below) is how the NAT IP Pool appears, if Static NAPT was chosen for
the Translation Mode parameter. Each entry in this configuration can be used to map
a global address and port to a local address and port. Notice that the global address
will be the external IP address of the global interface.

The parameter not explained in the previous sections is described as follows:

• Port –

This is a destination port number used by TCP and UDP to de-multiplex

incoming IP packets.

In the above example, incoming packets with the global destination IP Address
(211.11.22.3) and global destination TCP/UDP port (21) will be translated to a
packet with the local destination IP Address (1.1.1.5) and local TCP/UDP port (21).

Port 21 is assigned to FTP servers. Please see Appendix D for more commonly
assigned port numbers, or RFC 1700 for a more complete list.

Configure NAPT for Special Aps

Some applications programs that are used over the Internet such as Microsoft
NetMeeting, Diablo, CU See Me and Xwindows send information to a certain port
number or within a specified range of port numbers. The exact port number used is
specific to the application. However, if you find that you are having trouble using an

58

DI-206 ISDN Remote Router

application over the Internet and you are using NAPT, you may need to exempt
certain port numbers from the NAPT port translation process. Please refer to the user
guide for the program to find out whether it transmits and receives data only through
specified IP port numbers. In order for these programs to work with NAPT, the IP
port numbers required by these applications must be entered in the Configure NAPT
for Special APs screen shown below.

In the above window, position the cursor on any of the numbered name fields and
press <Enter>. This will take you to the NAPT configuration screen for special
applications shown below.

The fields in the above window are described as follows:

• Protocol

–

UDP

or

TCP

. This field designates the type of packets that will be

acted on.

• Start Port

– Some applications can only send data over a certain range of port

numbers. Thus, all port numbers in the specified range must be exempt from the

59

DI-206 ISDN Remote Router

NAPT port translation process. This field defines the beginning range of the port
numbers to be exempted from the NAPT port translation process.

• End Port

excluded from the NAPT process (see Start Port above).

• Connection Type

run the special application and send a request to the application server on the
Internet. This outgoing request to join a Diablo server, for example, is used to
trigger the exemption process for the incoming data.

In the example for the game Diablo shown in the above screen, if a packet is sent out
on the TCP port number 6112 (a request by a local user to a Diablo server on the
Internet to join a group game), all incoming packets on the UDP port 6112 (game
data) will not be translated by NAPT.

Please keep in mind that the user will always initiate use of the special application.
Thus, the first entry should always have the Connection Type of Outgoing Control.
Also, since the defined port number or range of port numbers will be mapped to the
user who triggered the outgoing control, all incoming data will be sent to that user.
Consequently, only one user can use the special application at a time.

Telnet/Discovery Enable

– This field defines the last port number in the range of numbers

Outgoing Control

–

Incoming Data

or

. The user must initially

The fields in the above window are described as follows:

• Telnet State

- This feature enables or disables the router’s ability to be

configured over the LAN using telnet.

• Discovery Function

– Enabling this feature allows the router to be auto-

discovered by D-Link SNMP management software and the included Windows-

60

RouteMan

.

based configuration software called

DNS Configuration

The DI-206 router has a built in recursive DNS server. The maximum amount of
memory that will be used by the router’s Domain Name Server is 64Kb which
averages out to be about 800 entries. In other words, up to 800 domain names and
their associated IP Addresses can be stored, which can significantly speed up access
to those domains. The routers DNS table will age out about every 24 hours, ensuring
that the most frequently accessed domains consistently benefit from the improved
access times provided by using the routers own DNS.

The IP Addresses for domain names not stored in the router must be acquired from a
DNS server on the Internet. Thus, if you are using DNS, make sure you also specify
an IP Address to a DNS server in the Forward DNS queries to field.

DI-206 ISDN Remote Router

The items in the above submenu are described as follows:

• DNS Server State

• Lookup Host Table

– Enables or disables recursive DNS on this router.

– Enables or disables DNS to reference up to eight host

names defined in the Host Table shown below.

• DNS Domain Name

– The domain name suffix in which the router resides, to be

appended to the host name defined in the host table.

• Forward DNS queries to

– A large server dedicated to resolving domain names
on the Internet. This field should contain the IP Address for the DNS closest to
you.

• DNS Cache State –

When this item is enabled, the router will add the domain

names and IP Addresses it retrieves from DNS replies to it’s DNS cache.

61

DI-206 ISDN Remote Router

Host Table

The host table allows the router to recognize host names on the network. Up to eight
host names can be entered in the table. Your network servers, especially your mail
server should be defined here. Leftover places in the table can be assigned to
individual hosts to speed up routing.

In the example below, the host name “ctsnow” is combined with the domain name
defined in the
produce “ctsnow.dlink.com”. The mapping in the example of “ctsnow.dlink.com” to
the IP Address of 11.1.1.3 is only valid for computers which set the DI-206 router as
their DNS server.

DNS Configuration

submenu above (in this case, “dlink.com”) to

Items are described as follows:

• IP –

• Host Name –

• State –

The IP address for the host.

The host name used by the host.

Enables or disables entry.

62

Radius Configuration

Radius is an authentication protocol where passwords are stored on a Radius server.
Radius allows large numbers of passwords to be stored in a centralized location.
Before instituting Radius, please setup and install a Radius server on the LAN.

DI-206 ISDN Remote Router

Items in the above submenu are described as follows:

• RADIUS State –

Enables or disables Radius. When enabled, all settings in the

Dial-in User Profile are disabled.

• Type –

Refers to the type of external password protocol. Currently, only Radius

is supported.

• Server IP Address –

This is the IP Address of your UNIX or NT-based Radius

server.

• Port –

The port number for the Radius server. The standard port number

specified by RFC 1700 is 1812 (shown above).

• Key –

This is a shared secret used to identify the router as a valid Radius client.

The Radius authentication service works for dial-in users only. Thus, when Radius is
enabled, passwords for dial-in users will no longer be checked in the

profile

. Instead, the authentication request will be passed on to the Radius server.

dial-in user

Remote networks (routers) dialing into the router will still be authenticated using the

remote network profile

.

Multi-Link PPP Configuration

Multi-link PPP (MLPPP) is a standard (RFC 1990 and RFC 1717) for inverse
multiplexing, a method of combining individually dialed channels into a single,
higher speed data stream. MLPPP is an extension of PPP that supports the ordering

63

DI-206 ISDN Remote Router

of data packets across multiple channels. Although MLPPP can be implemented on
any WAN device, it was the rapid emergence of ISDN BRI as a cost efficient higher
bandwidth alternative to modems which has driven the evolution and acceptance of
MLPPP. Typically MLPPP is used to combine the speed of two ISDN BRI B­Channels to get 128Kbps of virtual capacity.

Before implementing MLPPP on the DI-206, please ensure that your ISP or the
device to which you are connecting supports, and is configured for MLPPP.

MLPPP can be implemented in two ways, dynamically through the use of the
Bandwidth on Demand (BOD), and statically. BOD causes the second ISDN port to
place a call and add bandwidth to the ISDN connection when the BOD High
Threshold is exceeded for the Add Bandwidth Delay period. Bandwidth can also be
subtracted when ISDN throughput falls below the BOD Low Threshold and Subtract
Bandwidth Delay parameters. Thus, BOD economizes MLPPP by maintaining only
the bandwidth needed.

A static implementation of MLPPP is achieved when BOD is disabled but the ISDN
ports have Multi-Link enabled. In this case, when the two ISDN ports have
established a connection, the router will check to see if they are connected to the
same source and whether the source supports MLPPP. If both conditions are met, the
router will automatically bundle the two links together as an MLPPP connection.

Choosing

Items in the

• Bandwidth on Demand

Multi-Link PPP Configuration

Multi-Link PPP Configuration

– Enables or disables BOD. When enabled, BOD will

displays the following screen:

window are described as follows:

manage the implementation of MLPPP using the parameters defined in this
window.

• BOD Criteria

– Either TX, RX or

TX+RX

, where

TX

is Transmit and RX is
Receive. The parameter defined here is used when monitoring the BOD High
Threshold and BOD Low Threshold.

64

DI-206 ISDN Remote Router

• BOD High Threshold (%)

– (0 to 100) The throughput value as a percentage of
total bandwidth which will cause the next ISDN port having Multi-Link PPP
enabled to dial up and add bandwidth to the connection. This value, however,
must be constantly exceeded for the time designated in the Add Bandwidth Delay
field before the next ISDN port dials out.

• BOD Low Threshold (%)

– (0 to 100) The throughput value as a percentage of
total bandwidth which will cause the highest numbered ISDN port in the MLPPP
bundle to hang up, thus subtracting bandwidth from the connection. Before
actually hanging up however, the throughput must be below this value for the
time designated in the Subtract Bandwidth Delay field.

• Add Bandwidth Delay (sec)

– (0 to 300) The amount of time in seconds the
router will wait and sample the BOD Criteria before adding bandwidth once the
throughput exceeds the BOD High Threshold. This prevents costly bandwidth
from being unnecessarily added due to temporary bursts in traffic.

• Subtract Bandwidth Delay (sec)

– (0 to 300) The amount of time in seconds the
router will wait and sample the BOD Criteria before subtracting bandwidth once
the throughput falls below the BOD Low Threshold. This prevents bandwidth
from being unnecessarily subtracted due to temporary lulls in traffic.

The example Multi-link PPP settings shown in the

Multi-Link PPP Configuration

window above assumes that ISDN 1 and ISDN 2 each have a 64kbps connection
configured to dial up to the Internet. When ISDN 1 receives a packet destined for the
Internet it will dial the ISP and establish a connection. If the total throughput on
ISDN 1 (

TX + RX

) ever exceeds 80% of the 64kps (51.2kps), the router will sample
the line for an additional 5 seconds. If the traffic continuously exceeds 80% for the 5
second delay time, ISDN 2 will dial up and add bandwidth to the connection.
Assuming sustained traffic of 70kps, MLPPP will balance the traffic on the two
ISDN ports so they are handling roughly 35kps each. If the traffic on ISDN 1 +
ISDN 2 falls below 20% of the 128kps connection (25.6kps) for more than 10
seconds, ISDN 2 will hang up and all traffic will be handled by ISDN 1.

For the above configuration to work, both ISDN ports need to have been properly
setup to establish dial-out PPP connections, and have Multi-Link enabled. Also note
that ISDN 1, being the B-channel that initiated the call in the MLPPP bundle and
thus the primary link, is not subject to the BOD Low Threshold parameter and will
never hang up due to BOD considerations. The primary link can, however, be
subject to Dial on Demand (DOD) settings, and could thus disconnect if Dial on
Demand is enabled and the Idle Time parameter is met. Dial on Demand settings are
located in the

Advanced Functions, Dial Configuration

submenu.

Admin Configuration

This feature allows you to define two names and two passwords, respectively, for
logging in to the router for configuration and management, and is shown below:

65

DI-206 ISDN Remote Router

Please note any changes made here as they are necessary for logging into the console
program.

System Maintenance

Your console program includes many useful tools for maintaining your device.
These tools include updates on system status, upgrades to the system software,
analysis, diagnostic tools and more. This section will describe how to use these tools
in greater detail.

The

System Maintenance

sub-menu appears as follows:

System Status

The
as follows:

System Status

submenu displays key information about the router and appears

66

Statistics

DI-206 ISDN Remote Router

Counter

Under the

Statistics

submenu, counter tables are displayed for LAN, ISDN B1, and

ISDN B2:

This feature displays some of the counters contained in MIBII and the proprietary
MIB. The table is updated every 5 seconds, and the counter table can be reset by
performing a system reset on the router. Note that performing a system reset clears
ALL tables in the router, including the routing table.

LAN Counter Table

67

DI-206 ISDN Remote Router

• Tx Packets –

The total number of valid packets transmitted by the router since

the last reset.

• Tx Bytes –

• Tx Discard Packets –

• Tx Error Packets –

The total number of bytes transmitted by the router.

The number of packets dropped by the router.

The number of invalid packets transmitted by the router.

This hardware counter shows the sum of Collisions, Abort and Underrun packets.

• Tx Collision Packets –

The number of packets sent out of the router that collided
on the line. Some collisions are inevitable due to the shared nature of Ethernet.
Excessive collisions show excessive utilization of the network.

• Tx Abort Packets –

When the router transmits a packet and a collision occurs,
the router will wait a random period and try to retransmit the packet. If a collision
occurs 16 times in a row, the transmission will be aborted and be logged by this
counter. An aborted packet shows extremely heavy utilization of the network.

• Tx Underrun Packets –

Runt packets. The number of packets transmitted by the
router that are less than the allowed 64 octets minimum length. Underrun packets
occur due to jam signals generated by collisions, backpressure, etc.

• Rx Packets –

The number of valid packets received by the router.

• Rx Bytes –

The total number of bytes contained in the valid packets received by

the router.

• Rx Unknown Packets –

The number of packets received by the router that were

of an unsupported protocol.

• Rx Discard Packets –

• Rx Error Packets –

The number of packets dropped by the router.

The number of invalid packets received by the router. This
hardware counter shows the sum of CRC, FAE, Overrun, MPA and DFR error
packets.

• Rx CRC Packets –

The number of packets received that failed the CRC

checksum test.

68

DI-206 ISDN Remote Router

• Rx FAE Packets –

Frame Alignment Error. The number of packets received that

does not end on a byte boundary and the CRC does not match.

• Rx Overrun Packets –

The number of packets received that exceed the 1518
octet maximum length imposed on Ethernet packets. Overrun packets are
generated by some proprietary software applications.

• Rx MPA Packets –

Missed Packet. This is a count of packets intended for the
router, but at the time, the router could not receive the packet (usually due to the
temporary lack of receive buffers).

• Rx DFR Packets –

Deferred Packets. This is a count of incidents where CRS
(carrier signal lost) and COL both occur at the same time. These two events
happen simultaneously as a result of jabber (produced by faulty networking
equipment, usually NIC’s).

ISDN Counter Table

• Tx Packets –

The total number of valid packets transmitted by the router since

the last reset.

• Tx Bytes –

• Tx Discard Packets –

• Tx Error Packets –

The total number of bytes transmitted by the router.

The number of packets dropped by the router.

The number of invalid packets transmitted by the router.

This hardware counter shows the sum of Collisions, Abort and Underrun packets.

• Tx Underrun Packets –

Runt packets. This counter shows the number of packets
transmitted by the router that are less than the allowed 64 octets minimum length.
Underrun packets occur due to jam signals generated by collisions, backpressure,
etc.

• Tx Lost CTS Packets –

The number of Clear To Send packets that were lost by

the router.

• Rx Packets –

The total number of packets received by the router.

69

DI-206 ISDN Remote Router

• Rx Bytes –

• Rx Unknown Packets –

The total number of bytes contained in packets received by the router.

The number of packets received by the router that were

of an unsupported protocol.

• Rx Discard Packets –

• Rx Error Packets –

The number of packets dropped by the router.

The number of invalid packets received by the router. This
hardware counter shows the sum of NOA, Abort, CRC, Overrun, CD Lost,
Framing and Parity error packets.

• Rx NOA Packets –

Non-Octet Alignment. This counts the number of packets
received by the router that did not end on a byte boundary. The receipt of a
misaligned packet will generate a single NOA event regardless of the number of
misaligned octets in the packet.

• Rx Abort Packet –

The number of packets that were dropped due to user
generated breaks in the transmission that occurred while a packet is being
received.

• Rx CRC Packets –

The number of packets received that failed the CRC

checksum test.

• Rx Overrun Packets –

The number of packets received that exceed the 1518
octet maximum length imposed on Ethernet packets. Overrun packets are
generated by some proprietary software applications.

• Rx CD Lost Packets –

• Rx Framing Error Packets –

• Rx Parity Error –

Runtime Tables

The

Table

Carrier Detect Lost. This counts the number of Carrier

Detect packets that were lost by the router.

Packets with framing errors can occur on the
ISDN port only when using HDLC in sync mode. This parameter counts the
number of lost start/stop flags.

The number of times parity errors occurred on the line.

Runtime Tables

submenu features

IP Routing Table, ARP Table

, and

PPP

:

70

IP Routing Table

The IP Routing Table gives you a snapshot of the IP routing table. Table entries will
expire after the Age value in the table counts down to zero seconds (except for
entries for the router itself which have an age value of zero but will never expire).

DI-206 ISDN Remote Router

• IP Address –

This is the destination, network IP address from an incoming

packet.

• Netmask –

This mask is received from RIP exchanges and internal calculations,

as the router learns.

• Gateway –

This is the next-hop router for which the packet, with destination IP

Address and qualifying Netmask, will be forwarded.

• If –

This is the outgoing interface for which the acceptable, routing packet will be

forwarded.

• Hops –

This is the remaining hop-count.

71

DI-206 ISDN Remote Router

ARP Table

• Age –

This is the time-to-live (TTL) value.

The ARP Table maps the IP address with a MAC address.

PPP Table

• IP Address –

• MAC Address –

This is the network layer IP address.

This is the data link MAC address.

The PPP Table allows you to display the interface and link status for either ISDN
Link 1 or ISDN Link 2 from the

PPP Status

sub-menu.

• Interface –

The desired interface.

• Link Down –

The present link status.

72

Log and Trace

This feature files events and errors that occurred and allows individual packets to be
captured in a buffer. These items are to help D-Link technical support personnel
identify problems that may be affecting your router. If problems occur with your
router, D-Link technical support personnel will guide you through the use of these
features.

DI-206 ISDN Remote Router

Event/Error Log

Log Configuration

73

DI-206 ISDN Remote Router

This option allows you to enable or disable the Event/Error log and begin recording
events.

View Log File

This displays the Event/Error Log file shown below:

The parameters are described as follows:

• Code –

A special code for categorizing events. Some codes include:

0 Cold Start
1 Link Change
2 Tx Abort
3 Rx Abort
4 Connect/Disconnect
5 NAT Request
6 DHCP Request

74

DI-206 ISDN Remote Router

Trace Buffer

• Port –

• Time –

• Data –

The interface on which an event occurs.

Tick-times denoting when events occurred.

Data that helps technical support personnel evaluate the event.

This feature captures packets in a buffer to help D-Link technical support personnel
identify problems with your router.

Trace Buffer Configuration

The parameters are described as follows:

• Interface –

Select

LAN, ISDN B1

, or

ISDN B2

.

75

DI-206 ISDN Remote Router

• Direction –

• State –

Enables or disables the Trace buffer feature

Select In,

Out

, or

Both

.

View Trace Buffer

Displays the header of packets captured in the buffer.

The contents are described as follows:

• Interface

• Time

• Data

– This is the interface from which the packets were captured.

– In clock ticks. The time the packet was captured.

– The contents of the header of the packet.

Packet Triggered Last Call

This feature allows you to see the packet that caused the last call to be made.

76

Diagnostic

DI-206 ISDN Remote Router

This feature tests the connection between the router and connected peripherals on a
given interface. Please note that if Telnet is used to access the router, only the Ping
Test diagnostic is available from the menu below.

Connection Test

This feature tests a dial-out ISDN connection.

The parameters are described as follows:

• Interface –

• Phone Number –

The ISDN B-channel to be tested.

The phone number that will be dialed by the ISDN Interface.

Please ensure that a modem answers the phone on the other end.

77

DI-206 ISDN Remote Router

Ping Test

• Connection Test –

Position the cursor over this item and press <Enter> to begin
the test. The router will dial the phone number defined above, try to establish a
valid link with the answering ISDN device and hang up. This test can only be
performed if the Interface is disabled in the

Interface Configuration, ISDN

submenu.

• Dial Out

– Press <Enter> to begin the test. The router will dial the phone number
above and negotiate a connection with the answering device. In order for this test
to work, a Remote Network Profile must be created for the connection.

• Hang up

– Press <Enter> to hang up after Dialing Out.

This test makes sure there is an IP network connection to a particular IP address.

The parameters are described as follows:

• IP Address –

• Count –

• Delay (10ms) –

• Start Ping Test -

Loopback Test

The loopback test is used to test the path ISDN network between your phone
company’s switch and the router.

This is the IP Address of the device that the router will attempt to

reach. The router will check it routing table and try to locate the IP Address.

The number of pings (packets) that will be sent. A value of 0 will cause

pings to be sent continuously.

The amount of time in 10 millisecond intervals between each

ping in the Count.

Press <Enter> or <Return> to begin the test.

78

Press <Enter> on the screen above.

DI-206 ISDN Remote Router

System LAN

• Phone Number –

Enter your own phone number here to establish a connection

between your ISDN B1 and B2 channels.

• Packet Length

– [1 to 1500 bytes]. This field allows you to define different sized

data packets to test the ISDN line.

• Start Test -

Press <Enter> or <Return> to begin the test.

The System LAN test is used to diagnose the LAN port. It can only be run if the
LAN port is disabled in the

Interface Configuration

79

submenu.

DI-206 ISDN Remote Router

System ISDN

This test diagnoses the ISDN ports. It can only be run if the ISDN port is disabled in
the

Interface Configuration

submenu.

Software Update

New routing software can be downloaded from a TFTP server.
If you do not have a TFTP server on your LAN, you can use the included Router

Configuration Utility to upgrade the software. This Windows-based utility has a
built-in TFTP emulator enabling you to use the computer (connected to the LAN and
running the Configuration Utility) to upload the new software to the router.

80

DI-206 ISDN Remote Router

This is the same Software Update configuration information contained in the

Software Update

section in the “

PROM System Configuration”

chapter. The

parameters are described in that section.
Perform a System Restart after configuring these settings begins the software update

procedure.

System Restart

The system restart function enables you to reset the DI-206 without powering off.
Some setting changes require a system restart in order for them to take effect.

A system restart will not affect the router’s settings, but will clear all tables
including the routing table and all SNMP counters and tables. It is also used to
initiate a software update.

81

DI-206 ISDN Remote Router

Factory Reset

Performing a factory reset erases all settings and tables. All configuration changes
ever made to the router will be deleted. The router will be set to the factory defaults
it was shipped with and will no longer have an IP address.

Please make sure you wish to wipe out all settings and configure the router from
scratch before you perform a factory reset

System Settings Backup/Restore

The backup and restore system settings functions are used to backup the router
settings. The files created by these processes are different than configuration files or
software update files that are used in the
defined here can be used as a backup for all the router settings and can be used to
configure another DI-206 with exactly the same settings, or as a backup before you
make major changes to the configuration.

Software Update

submenu. The files

82

Backup System Settings

Items in the window are described below:

DI-206 ISDN Remote Router

• Remote IP Address

wish to store the settings file.

• TFTP Time Interval

If the router doesn’t receive a response (ACK) from the TFTP server within the
time interval defined here, it will assume the request has been dropped and send
another.

• File Name

settings file.

Restore System Settings

– This is the IP address of the TFTP server on which you

– The time between requests to occupy TFTP server time.

– Specifies the complete path and filename on the TFTP server for the

Items in the window are described below:

83

DI-206 ISDN Remote Router

• Remote IP Address

– This is the IP address of the TFTP server on which you

wish to restore the system settings file.

• TFTP Time Interval

– The time between requests to occupy TFTP server time.
If the router doesn’t receive a response (ACK) from the TFTP server within the
time interval defined here, it will assume the request has been dropped and send
another.

• File Name

– Specifies the complete path and filename on the TFTP server for the

settings file.

84

PROM System Configuration

The PROM program is run before the normal console (runtime) configuration
program in the router’s Flash Memory. Thus, the PROM System Configuration can
be used if there are problems with the router’s console program.

Specifically, the PROM Configuration program has procedures to initialize the
administration parameters and the LAN IP address of the router in order to allow the
console software in the router’s flash memory to be replaced if it has been damaged
or deleted.

DI-206 ISDN Remote Router

To enter the
procedure. The following menu will appear:

System Configuration

PROM System Menu

, press Ctrl+C during the Router’s POST

The parameters are described as follows:

85

DI-206 ISDN Remote Router

• Hardware Revision –

• Boot PROM Firmware Version –

router.

• MAC Address –

This is the physical address for this router.

TCP/IP Parameters Configuration

This is the version ID of hardware used in this router.

This is the version ID of firmware used in this

System Reset

The parameters are described as follows:

• Interface –

The LAN interface must use Ethernet/Fast Ethernet and is displayed

here. This setting cannot be adjusted.

• IP Address –

• Subnet Mask –

This is the router’s IP Address for the LAN interface.

This mask shows how the LAN is to be divided into network,

subnet, and host parts.

• Default Gateway –

This is the default gateway for the LAN. If this router will be

the default gateway for the LAN, then the address should be 0.0.0.0.

• Send BootP request upon power up –

If set to

Yes

, when the router boots up, it
will attempt to acquire the path to the image file, the TFTP server IP Address and
the routers own IP Address.

The system reset function enables you to reset the DI-206 without powering off.
Some setting changes require a system reset in order for them to take effect.

A system reset will not affect the router’s settings, but will clear all tables including
the routing table and all SNMP counters and tables. It is also used to initiate a
software update.

86

Software Update

The Software Update option is used to change the software in the flash memory of
the router. This is the runtime software that is configured by the console and is used
to setup the router and is described in full in the preceding chapter.

The runtime software should only be updated if you are encountering problems with
your current runtime software or you are certain your runtime software is lacking
functionality contained in a more recent version.

Downloading new software will only replace the runtime software and will not affect
any configuration settings you have made. Upon running the new software, the
router will be configured exactly as you had it before downloading the new software.

The runtime software (image file) must be stored on a TFTP server and accessed via
the LAN.

DI-206 ISDN Remote Router

Items listed in the above menu are described as follows:

• Software Update Control –

• Software Update Mode –

This toggles disable and enable.

This specifies downloading the image file from a

Network server on the local LAN.

• Boot Protocol –

TFTP

and

TFTP

•

This setting is for a local network download and has two options

BootP&TFTP

A File Transfer Protocol. Using this setting assumes all other items

–

.

on this screen have been filled out.

BootP&TFTP

•

BootP is run first and sends your router IP Addresses for the

–

TFTP server and the router, and tells the router the path to the software
update (image file). Then TFTP will be used to download the image file.

• Boot Server IP Address –

This specifies the IP address of the server to be used

to download the image file.

• Boot File Name –

This specifies a complete path and filename on the TFTP

server. If you choose to use a configuration file, this setting must show the path

87

DI-206 ISDN Remote Router

and filename to the configuration file. If you are not using a configuration file,
this must show the path and filename to the software update image file.

• Last Boot Server IP Address –

download an image file. This is for reference only.

• Last IP Address –

Again, this is for reference only. The LAN port must have an IP address in order
to access the TFTP server via the LAN network.

• Update Software from Configuration File –

software update procedure will try to access a configuration file located at the
path defined in the above Boot File Name. Please ensure that the path and file
name of the image file is listed in the configuration file. If set to No, the update
procedure will try to find an image file at the Boot File Name path. Please see
Appendix F, “

After the parameters are set in the
EXIT, and perform a System Reset or Execute Bootload to begin the software
download process.

After the new runtime software has been downloaded, the router will automatically
start up using the new software with the Software Update Control setting
to avoid a downloading loop.

EEPROM Factory Reset

This shows the last boot server used to

This shows the last IP address used for the LAN interface.

Yes

or No. If

screen, SAVE the changes,

Configuration File”

Software Update

Either

for more information about configuration files.

Yes

, the

Disabled

Performing a factory reset erases all settings and tables. All configuration changes
ever made to the router will be deleted. The router will be set to the factory defaults
it was shipped with and will no longer have an IP address.

Please make sure you wish to wipe out all settings and configure the router from
scratch before you perform a factory reset.

Execute Bootload

Choosing this option accepts the changes made in the PROM program and begins
the router’s startup sequence.

88

DI-206 ISDN Remote Router

Executing a bootload can also begin the Software Update procedure, if enabled.

89

DI-206 ISDN Remote Router

Using Telnet

The DI-206 router can be configured and managed using telnet. Telnet accesses the
same built-in configuration program as the RS-232 Diagnostic port console
connection. As such, all settings that can be adjusted through the console can also be
configured using Telnet.

Telnet Configuration

In order to use telnet, the DI-206 router must first be configured using a console
connected to the RS-232 Diagnostic port. Depending on the placement of the
management station using telnet, the initial configuration requirements for the router
are as follows:

Using Telnet via LAN

Preparing the router for management by telnet over the LAN only requires enabling
the LAN port, enabling telnet, and assigning the LAN port an IP address. To do this:

1. Connect a console to the RS-232 Diagnostic port on the front panel of the router
and run a terminal emulation program (for more information, see

Console to the Router

2. Enable the LAN port in the

3. Assign an IP address to the LAN port in the

4. Enable Telnet in the

5. Connect the router to the LAN.

The router can now be accessed via the LAN by the included Windows-based
Configuration program, Telnet and SNMP management applications. For more
detailed information regarding these procedures, please refer to the

Router

refer to the

Using Telnet via ISDN

section of this manual. For more information about the submenus, please

Setting Up the Console

and

Interface Configuration

Advanced Functions

Configuration and Management

sections of this manual).

sub-menu.

Network Configuration

submenu.

section of this manual.

Connecting the

sub-menu.

Connecting the

Preparing the router for management by telnet over ISDN lines requires more initial
configuring of the router via the console.

To do this, you must configure an ISDN port for dial-in users. Please refer to the

Interface Configuration, ISDN

submenu section of this manual.

90