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Megabit Modem CRA-C

User Manual

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Manual Number: 425-613-150-02

Megabit Modem CRA-C User Manual P/N 425-613-150-02 Revision 02 May 1998

Technologies, Inc. and shall not be modified, used, copied, reproduced or disclosed in whole or in part without the written consent of PairGain.

PairGain is a registered trademark, and Megabit Modem is a trademark of PairGain Technologies, Inc.

Other product names mentioned in this manual are used for identification purposes only and may be trademarks and/or registered trademarks of their respective companies.

The information in this publication is believed to be accurate in all respects. However, PairGain Technologies cannot assume responsibility for any consequences resulting from the use thereof. The information contained herein is subject to change. Revision to this publication or new additions to it may be issued to incorporate such changes.

ii Megabit Modem CRA-C User Manual

FCC NOTICE

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 designed to provide reasonable protection against harmful interference when the equipment is operated in a commercial environment. This equipment generates, uses, and can radiate radio frequency energy and, if not installed and used in accordance with this instruction manual, may cause harmful interference to radio communication.

However, there is no guarantee that interference will not occur in a particular installation. If this equipment does cause harmful interference to radio or television reception, which can be determined by turning the equipment off and on, the user is encouraged to try to correct the interference by one or more of the following measures:

•

Reorient or relocate the receiving antenna.

•

Increase the separation between the equipment 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.

Any changes or modifications not expressly approved by the grantee of this device voids the user’s authority to operate the equipment.

Megabit Modem CRA-C User Manual iii

DECLARATION OF CONFORMITY

Manufacturer’s name and address:

declares that

Product name:

conforms to the following

Standards:

Application of Council Directives:

I, the undersigned, hereby declare that the equipment specfied above conforms to the above directives and standards.

Signature:

PairGain Technologies, Inc. 14402 Franklin Ave

Tustin, CA 92780-7013 U.S.A.

Megabit Modem CRA-C

EN55022 (1987), EN50082-1 (1992), EN60950 (1994)

89/336/EEC, 73/23/EEC

Roy Stephens, Director of Quality Assurance

Place: Date:

iv Megabit Modem CRA-C User Manual

Tustin, CA, U.S.A. March 16, 1998

USING THIS MANUAL

This manual helps you:

understand the features of the PairGain® Megabit Modem™ CRA-C

•

and how the unit operates as a component within a network install the Megabit Modem CRA-C

•

configure your unit to operate within the network

•

contact PairGain if you need additional help

•

Three types of messages with icons appear in the text:

Notes inform you of special circumstances.

Cautions indicate the possibility of damage to equipment.

Warnings indicate the possibility of personal injury.

Megabit Modem CRA-C User Manual v

Using This Manual

vi Megabit Modem CRA-C User Manual

CONTENTS

ABOUT THE MEGABIT MODEM CRA-C __________________ 1

INSTALL THE MEGABIT MODEM CRA-C_________________ 7

CONFIGURE AND VIEW STATUS________________________ 17

About Rate Adaptive Transmission..................................... 2

Rate Adaptation.............................................................. 2

Reach, Data Rate, SNR Margin,

and Noise Environment............................................ 4

Unpack and Inspect the Shipment....................................... 7

Identify LEDs and Connectors............................................ 9

Front Panel..................................................................... 9

Rear Panel....................................................................11

Install the Megabit Modem CRA-C ..................................12

Connect to the ADSL Line ........................................... 12

Connect to the Data Network ........................................ 13

Power Up and Check LEDs .............................................. 16

Connect to an ASCII Terminal.......................................... 17

How to Log On and Navigate the Menus .......................... 19

How to Configure a Remote Unit...................................... 23

Configure System Settings................................................ 24

Configure ADSL Transceiver ........................................... 26

Configuration ............................................................... 26

Reset ADSL Transceiver .............................................. 29

Configure the Bridge/Router............................................. 30

Configure as a Bridge................................................... 31

Configure as a Router................................................... 34

Configure SNMP..........................................................38

Reset the Ethernet Bridge.............................................40

View Status ...................................................................... 41

System Information ...................................................... 41

ADSL Transceiver Status.............................................. 42

Ethernet Bridge Statistics.............................................. 48

Log Out............................................................................49

Megabit Modem CRA-C User Manual vii

Contents

NETWORK AND MANAGEMENT OVERVIEW____________ 51

MAC Layer Bridging and Spanning Tree Protocol............51

Static IP Routing............................................................... 53

Megabit Modem CRA-C IP Addresses..........................59

Management Protocols...................................................... 61

SNMP...........................................................................61

Megabit Modem CRA-C SNMP Agent .........................62

MIB and Trap Support.................................................. 63

Network Configuration and Image Code Download ..........64

BOOTP.........................................................................64

TFTP ............................................................................66

Encapsulation Protocols....................................................66

TECHNICAL SPECIFICATIONS _________________________ 67

TECHNICAL ASSISTANCE______________________________ 69

World-Wide Web..............................................................69

FTP ..............................................................................69

LIMITED WARRANTY _________________________________ 71

GLOSSARY____________________________________________ 73

viii Megabit Modem CRA-C User Manual

ABOUT THE MEGABIT MODEM CRA-C

The PairGain® Megabit Modem™ CRA-C uses Asymmetric Digital Subscriber Line (ADSL) technology to provide, on a single pair telephone line, a multi-megabit Ethernet connection between the subscriber and the service provider. The Megabit Modem CRA-C transmits data up to 3.16 Mbps from a service provider and receives data up to 1.08 Mbps from a subscriber. The Megabit Modem CRA-C is rate adaptive; its speed is adjusted to the maximum attainable data rate depending on distance and line condition. Additionally, ADSL technology allows ordinary telephone service to coexist with the high-speed data service on the same wire pair.

The rate-adaptive Megabit Modem allows the service provider to deliver the best possible data rate for any subscriber. Typically, a subscriber closest to the provider receives the highest data rate available, while subscribers farther away receive data at a lower transmission rate.

The Megabit Modem CRA-C has field-proven Carrierless Amplitude-modulation and Phase-modulation (CAP) line coding. The 2-dimensional, 8-state Trellis coding with Viterbi decoding and the Reed-Solomon forward-error-correction provide robust transmission in harsh environments.

Use the Megabit Modem CRA-C for application solutions, particularly those requiring high-speed transmission to the subscriber, such as:



Internet access



remote Local Area Network (LAN) access



telecommuting small office or home office

•

Other features of the Megabit Modem CRA-C include:



embedded Simple Network Management Protocol (SNMP) agent



IEEE 802.1d transparent MAC level bridging with Spanning Tree protocol support



static IP routing to provide secure access to the Internet



BOOTP and TFTP to download software



10BASE-T Ethernet port for connection to an Ethernet LAN



line port for Rate-adaptive ADSL single-pair connection console port for maintenance and management

•

Megabit Modem CRA-C User Manual 1

About the Megabit Modem CRA-C

Use the Megabit Modem CRA-C with these other PairGain products:

Megabit Modem CRA (at subscriber site)

•

S1 Network Interface Device (network interface at subscriber site)

•

About Rate Adaptive Transmission

The following definitions are useful for understanding the operation of the Megabit Modem:

Bit Error Rate (BER) is the ratio of received bits that are in error

•

relative to the total number of bits received, measured over time. For example, 10

bits received.

Signal to Noise Ratio (SNR) is the ratio (typically expressed in dB) of

•

the received signal power to the received noise power. It is a measure of the quality of the transmission. The theoretically achievable BER can be extrapolated from the measured SNR.

Margin (SNR margin) is the amount of degradation in SNR that the

•

system can tolerate under the current conditions and still achieve a

-7

BER. A margin of 6 dB, for example, would mean that the SNR can degrade by 6 dB and still provide a performance of 10 PairGain Megabit Modem CRA-C has a margin configuration option that defaults to 6 dB, but may be set anywhere between -3 dB to 9 dB.

-7

BER means that on average one error occurs per

-7

BER. The

Reach is the longest loop length that the system can support with

•

a given margin and a BER of less than 10

-7

at the given data rate.

Rate Adaptation

With PairGain's rate adaptive technology, the Megabit Modem CRA-C can automatically adjust to the fastest speed possible, given the transmission distance and line conditions. Alternatively, the provider can manually set the modem to a specific rate. The available data rates are:

downstream (transmit) rates: 3.168 Mbps, 2.528 Mbps, 2.208 Mbps,

•

1.888 Mbps, 1.568 Mbps, 1.248 Mbps, 928 Kbps, 608 Kbps upstream (receive) rates: 1.080 Mbps, 944 Kbps, 808 Kbps, 672 Kbps,

•

536 Kbps, 400 Kbps, 264 Kbps, 82.66 Kbps

2 Megabit Modem CRA-C User Manual

About the Megabit Modem CRA-C

The Megabit Modem CRA-C can be set to any one of three modes that determine how the data rate is selected. It is important to note that rate adaptation occurs only during startup. The Megabit Modem CRA-C will not change its data rate while the link is up. The three startup modes are:

Full startup always:

•

the highest upstream and downstream data rates it can support under the current line conditions, with a margin greater than or equal to the configured margin. This is done during every ADSL startup attempt. The system will always attempt a full startup where it will set a transmission rate up to the maximum specified. It determines this rate by assessing the signal quality data (line length and noise conditions, for example) and the margin configuration setting. It then comes up in the highest available rate based on this information.

In the full startup mode, the system figures out

Session startup:

•

rates set during a previous full startup, rather than re-assessing the signal quality data. In this mode the system performs a full startup upon every powerup or reset and would also revert back to a full startup attempt when a session startup is not successful for 30 seconds.

Fixed data rate:

•

programs both the upstream and the downstream data rates using the Transceiver Configuration Menu. The user can select from available data rates shown above. Another configuration parameter is the startup SNR margin that is also configurable using the Transceiver Configuration Menu. The system will attempt to come up to the programmed data rates with a margin greater than or equal to the configured margin. Failure to complete startup with the desired margin results in repeated attempts to accomplish it.

When a connection is lost in any mode (the cable disconnected, for example), the system attempts reconnection as if it has been reset.

In session startup mode, the system uses the data

In a fixed-rate mode (fixed data rate), the user

Megabit Modem CRA-C User Manual 3

About the Megabit Modem CRA-C

Reach, Data Rate, SNR Margin, and Noise Environment

The maximum transmission rate of the Megabit Modem CRA-C is determined by distance, SNR margin, and the condition of the line (wire gauge, condition noise environment). Figure 1 shows the relationship between reach and data rate for a given set of conditions. The plots can be used to determine the achievable reach at a given data rate, or they may be used to determined the achievable data rates at a given distance. In all of the cases except the no noise case, a margin of 6 dB was allocated above the SNR that provides a Bit Error Rate (BER) of 10

These line conditions fall within the range of the plots shown in Figure 1:

no noise (0 dB margin)

•

low noise (−140 dBm-Hz Additive White Gaussian Noise (AWGN))

•

24 ISDN lines in the same binder group

•

24 HDSL lines in the same binder group

•

24 ADSL lines in the same binder group

•

10 T1 lines in an adjacent binder group

•

-7

one T1 line in the same binder group

•

The performance shown is "typical" for PairGain Megabit Modem CRA products. Due to variations in environment and test setup, PairGain does not guarantee performance to the figures shown.

One of the configuration options in the Megabit Modem CRA-C is the startup margin setting. This setting defaults to 6 dB but may be set from

-3 dB to 9 dB. The modems will attempt to come up at the programmed margin setting. Setting the margin high allows for a cushion against changing line conditions and impulse noise. Setting the margin low provides less protection but allows the modems to come up at a higher data rate (if in the rate-adaptive modes) or at a longer loop length (if in the fixed data rate mode). The default setting of 6 dB is recommended and provides an overall BER better than 10 less than 10

4 Megabit Modem CRA-C User Manual

-10

. Reducing the setting to 0 dB will only provide a BER of

-7

and is not recommended.

About the Megabit Modem CRA-C

Figure 1.

Megabit Modem CRA-C User Manual 5

Reach for a Rate Adaptive ADSL Megabit Modem

About the Megabit Modem CRA-C

6 Megabit Modem CRA-C User Manual

INSTALL THE MEGABIT MODEM CRA-C

Install the Megabit Modem CRA-C using these sections:

For information about this topic Go to page

Unpack and inspect the shipment 7 Identify LEDs and connectors 9 Install the Megabit Modem CRA-C 12 Power up and check LEDs 16

Unpack and Inspect the Shipment

Upon receipt of the equipment:

1 Unpack each container and visually inspect it for signs of

damage. If the equipment has been damaged in transit, immediately report the extent of damage to the transportation company and to your sales representative. Order replacement equipment if necessary.

2 Check the contents to the packing list to ensure complete and

accurate shipment. If the shipment is short or irregular, contact your sales representative. If you must store the equipment for a prolonged period, store the equipment in its original container.

The shipping carton contains, in addition to the Megabit Modem CRA-C and this manual, the cables described in Table 1.

Megabit Modem CRA-C User Manual 7

Install the Megabit Modem CRA-C

Table 1.

Cables for Megabit Modem CRA-C

Item Description Function

Straight-through Category 3 cable

Cross-over Category 5 cable

ADSL cable Gray UTP cable

Console cable Flat, silver, eight-wire

Console adapter A rectangular DB-9 (F)

Black unshielded twisted-pair (UTP) cables terminated with RJ-45 connectors.

Yellow UTP cable terminated with RJ-45 connectors.

terminated with RJ-11 and RJ-45 connectors.

cable with RJ-45 connectors at each end.

to RJ-48 adapter with two captive mounting screws.

Connects the Megabit Modem CRA-C Ethernet MDI-X port to a network device with an MDI port.

Connects the Megabit Modem CRA-C Ethernet MDI-X port to a network device with an MDI-X port.

Connects the Megabit Modem CRA-C to the ADSL line.

Plugs into the Console port to connect the Megabit Modem CRA-C to an ASCII terminal. Do not use as a 10BASE-T Ethernet cable.

Optional. Connects the Megabit Modem CRA-C to an ASCII terminal for configuration and viewing status.

Power supply An AC to DC power

supply that plugs into the power outlet.

Do not tamper with the power supply safety prong. It is a critical element for the secondary lightning protection provided within the Megabit Modem CRA-C. If you tamper with the safety prong, you risk serious injury.

8 Megabit Modem CRA-C User Manual

Provides primary power to the Megabit Modem CRA-C and establishes a safety ground.

Install the Megabit Modem CRA-C

Identify LEDs and Connectors

The Megabit Modem CRA-C front panel has LEDs that show status for power and data transmission. The rear panel has external interface connectors and a power switch.

Front Panel

Figure 2 and Table 2 describe the LEDs on the Megabit Modem CRA-C front panel.

Figure 2. Megabit Modem CRA-C Front Panel

Megabit Modem CRA-C User Manual 9

Install the Megabit Modem CRA-C

Table 2.

Front Panel LEDs

LED Mode Description

Power Green Indicates power is on. 10BASE-T

LINK Green

Off

TX Green

Off

COL Green

Off

ADSL

SYNC Solid green

Flashing green Off

STAT Solid green

Ethernet connection up. Ethernet connection down. Transmit activity at port. No transmit activity at port. Collisions occurring on the port. No collisions occurring on the port.

Normal operation. Training in progress. Megabit Modem CRA not synchronized with

Megabit Modem CRA-C. Normal operation.

Flashing green

MAR Solid green

Flashing green

10 Megabit Modem CRA-C User Manual

Test/Alarm condition exists. Margin is above threshold. Margin is below threshold.

Install the Megabit Modem CRA-C

Rear Panel

Figure 3 and Table 3 describe the Megabit Modem CRA-C rear panel features.

Figure 3.

Megabit Modem CRA-C Rear Panel

Table 3.

Rear Panel Components

Name Function

POWER connector 6-pin mini-DIN type port that supplies power to Megabit

Modem CRA-C.

Do not connect any other wall-plug supply to the Megabit Modem CRA-C unit, otherwise, you can permanently damage the unit.

ON/OFF switch Toggle switch used to turn modem ON and OFF. CONSOLE port RJ-45 connector (RS-232 compatible) used to connect an

ASCII terminal for configuring the Megabit Modem(s).

10BASE-T MDI-X port

ADSL port RJ-48 port used to connect the Megabit Modem CRA-C to the

RJ-45 MDI-X (cross-over) port used to connect the Megabit Modem CRA-C to a 10BASE-T port of a data network device.

ADSL transmission line.

Megabit Modem CRA-C User Manual 11

Install the Megabit Modem CRA-C

Complete the steps in the order listed to install the Megabit Modem CRA-C:

connect to the ADSL line

•

connect to the data network

•

Connect to the ADSL Line

The Megabit Modem CRA-C requires a single pair of telephone wires to connect the subscriber to the service provider. One wire is the Tip and the other is the Ring. See Table 4 for pinouts. Connect the Tip and Ring wires to your Megabit Modem CRA-C:

1 Plug the RJ-45 connector of the ADSL cable (gray) into the

ADSL port on the Megabit Modem CRA-C rear panel (Figure 4).

2 Connect the RJ-11 connector to the ADSL line.

Figure 4.

12 Megabit Modem CRA-C User Manual

Connecting to the ADSL Line

Install the Megabit Modem CRA-C

Table 4.

ADSL Pin Assignments for RJ-45 Connector

Pin Signal

1 Not Used 2 Not Used 3 Not Used 4 ADSL (Ring) 5 ADSL (Tip) 6 Not Used 7 Not Used 8 Not Used

Connect to the Data Network

The 10BASE-T MDI-X port connects the Megabit Modem CRA-C to the data network. If the data network has an MDI-X port, use the yellow cross-over Category 3 or better cable. If the data network has an MDI port, use the black straight-through Category 3 or better cable.

Table 5 and Figure 5 show the 10BASE-T Ethernet interface data signals for both MDI and MDI-X configurations.

Table 5.

10BASE-T Interface Control Signals

MDI Pin MDI-X Pin Signal Description

1 3 TD+ Transmit Data (+) 2 6 TD- Transmit Data (-) 3 1 RD+ Receive Data (+) 44- 55- 6 2 RD- Receive Data (-) 77- 88- -

Megabit Modem CRA-C User Manual 13

Install the Megabit Modem CRA-C

Figure 5

14 Megabit Modem CRA-C User Manual

. Straight-through and Cross-over Cable Pinouts

Install the Megabit Modem CRA-C

Connect to the data network using either the black straight-through cable or the yellow cross-over cable:

1 Plug the RJ-45 connector of the Category 3 cable into the

10BASE-T MDI-X connector on the Megabit Modem CRA-C rear panel (Figure 6).

2 Attach the other end of the Category 3 cable to the 10BASE-T

port of your data network.

Figure 6.

Megabit Modem CRA-C User Manual 15

Connecting to the Data Network

Install the Megabit Modem CRA-C

Power Up and Check LEDs

Install the power cable and power up the Megabit Modem CRA-C:

1 Plug the mini-DIN connector on the wall-plug supply into the

power connector on the rear of the Megabit Modem CRA-C, then plug the wall-plug supply into the facility power.

Do not connect any other wall-plug supply to the Megabit Modem CRA-C. If you use another wall-plug supply, you can permanently damage the unit.

2 Turn ON the ON/OFF switch on the rear panel. The unit enters a

self-test mode with the following LED indications:

ADSL STAT LED flashes green

•

ADSL SYNC LED flashes green

•

Power LED lit solid green

•

Allow the Megabit Modem CRA-C approximately 30 to 60 seconds to synchronize with the Megabit Modem CRA at the other end of the ADSL line.

3 Verify the following LED indications (after the self test is

completed):

10BASE-T LINK LED is solid green (when the Ethernet port

•

is connected) ADSL SYNC LED is solid green

•

ADSL STAT LED is solid green

•

ADSL MAR LED is solid green

•

If conditions other than those listed above exist, check the installation. See Table 2 for a description of the front panel indications.

16 Megabit Modem CRA-C User Manual

CONFIGURE AND VIEW STATUS

In this chapter, you configure the Megabit Modem CRA-C or view system status using an ASCII terminal connected to the console port. Go to the following sections:

To complete this task

Connect to an ASCII terminal 17 How to log on and navigate the menus 19 How to configure a remote unit 23 Configure the system settings 24 Configure the ADSL transceiver 26 Configure the Bridge/Router 30 View status 41 Log out 49

Go to page

Connect to an ASCII Terminal

Connect the Megabit Modem CRA-C to an ASCII terminal:

1 Plug the console adapter into the standard 9-pin COM port on

the ASCII terminal and tighten the captive screws until they are snug (Figure 7). (Skip this step if the ASCII terminal has an RJ-48 jack.)

2 Connect one end of the silver console cable to the

console adapter.

3 Connect the other end of the silver console cable to the console

port on the Megabit Modem CRA-C rear panel.

Megabit Modem CRA-C User Manual 17

Configure and View Status

Figure 7. Connecting to an ASCII Terminal

4 Configure these communication settings for the ASCII terminal:

9600 to 19,200 baud

•

no parity

•

8 data bits

•

stop bit

•

flow control to OFF

•

5 Select ANSI for terminal emulation.

18 Megabit Modem CRA-C User Manual

Configure and View Status

How to Log On and Navigate the Menus

This section shows you how to log on and then how to navigate the menu structure. Every console screen has a menu header which displays the time in the upper right corner and the date in the upper left corner.

Through the menus, you can configure a local and a remote modem. The header on each menu screen identifies the modem being monitored or configured:



ATU-C is the ADSL Transceiver Unit (ATU) at the service provider site which is the Megabit Modem CRA-C.



ATU-R is the remote Megabit Modem CRA at the subscriber site

Log on to the Megabit Modem CRA-C:

1 Press the spacebar several times to activate the autobaud feature

and to display the Logon Password screen.

07/2/97 PAIRGAIN TECHNOLOGIES 08:42:36 ATU-C ADSL MEGABIT MODEM TERMINAL 01.01

LOGON PASSWORD>

Megabit Modem CRA-C User Manual 19

Configure and View Status

ENTER

establish a different password, you must type the new password at the LOGON PASSWORD prompt on a subsequent log on.

2 Type your password at the password prompt or press

(factory default password) if you have not customized your password. The Main Menu displays.

07/02/97 PAIRGAIN TECHNOLOGIES 08:43:18 ATU-C ADSL MEGABIT MODEM TERMINAL 01.01

MAIN MENU

1. SYSTEM STATUS AND CONFIGURATION

2. ADSL MENU

3. BRIDGE/ROUTER MENU

4. REMOTE LOGON

Q. LOGOUT

ENTER CHOICE-->

is the factory-default password. If you

ENTER

See the section, "Configure System Settings," to establish a new password.

20 Megabit Modem CRA-C User Manual

Configure and View Status

Figure 8 shows the structure for the Megabit Modem CRA-C menus. Type the number of the menu item you want to view or configure.

Figure 8.

Megabit Modem CRA-C User Manual 21

Megabit Modem CRA-C Menu Structure

Configure and View Status

Table 6 shows the ASCII terminal key functions used to navigate the menus and to select settings.

Table 6.

Keyboard Functions

Key Function

ESC

Restores the parameter to the last saved setting. Applies to parameters where you type a value but not to parameters you toggle.

Ctrl

Goes to Main Menu. Performs a log out from the Main Menu. Returns to the next higher-level menu. Refreshes the current screen.

Toggles between ATU-C and ATU-R menus.

Status Menus and Reports

Clears the current values. Selects the next page. Selects the previous page. Restores previous setting by undoing the last action.

When configuring Megabit Modem CRA-C parameters:

Toggle among predefined optional settings (for example, select



STARTUP OPTION in the ADSL Configuration Menu and then toggle through the choices) as follows:

Type the number of the option.

ENTER

Press the spacebar to select the new setting, then press

Type required information (for example, to change system time, type



ENTER

in the hour, minute, and second as hh:mm:ss) as follows:

Type the number of the option. The screen prompts you to type

specific information. Type the information, following the instructions on the screen,

ENTER

then press

22 Megabit Modem CRA-C User Manual

Configure and View Status

How to Configure a Remote Unit

From the Megabit Modem CRA-C, you can view system parameters and set configuration options for the remote Megabit Modem CRA. The remote console menu header reflects the remote unit as ATU-R. This shows that the console program is physically connected to the unit at the service provider site (ATU-C), but is virtually configuring the unit at the subscriber site (ATU-R).

At the Main Menu, type status menus for Megabit Modem CRA (remote ATU-R).

07/02/97 PAIRGAIN TECHNOLOGIES 08:43:18 ATU-C ADSL MEGABIT MODEM TERMINAL 01.01

MAIN MENU

1. SYSTEM STATUS AND CONFIGURATION

2. ADSL MENU

3. BRIDGE/ROUTER MENU

4. REMOTE LOGON

Q. LOGOUT

ENTER CHOICE-->

for Remote Logon to display the configuration and

The following Remote Logon screen is displayed.

07/02/97 PAIRGAIN TECHNOLOGIES 08:42:28 ATU-R ADSL MEGABIT MODEM TERMINAL 01.01

LOGON PASSWORD>

Optionally, you can press

Ctrl

T at the logon screen or at any menu shown in the menu tree (Figure 8) to toggle between the local and remote Megabit Modems.

Megabit Modem CRA-C User Manual 23

Configure and View Status

Configure the System Settings

This section describes configurable system settings. You can change factory default settings like time and date, or create a password and unique ID for the unit.

1 On the Main Menu, type

Configuration menu.

07/02/97 PAIRGAIN TECHNOLOGIES 08:43:23 ATU-C ADSL MEGABIT MODEM TERMINAL 01.01

SYSTEM STATUS AND CONFIGURATION

1. SYSTEM INFORMATION

2. SYSTEM CONFIGURATION

(M)ain

ENTER CHOICE-->

to display the System Status and

2 Type

07/02/97 PAIRGAIN TECHNOLOGIES 08:54:52 ATU-C ADSL MEGABIT MODEM TERMINAL 01.01

SYSTEM CONFIGURATION

1. CHANGE SYSTEM TIME

2. CHANGE SYSTEM DATE

3. CHANGE PASSWORD

4. FACTORY DEFAULT CONFIGURATION

(R)eturn (M)ain

ENTER CHOICE-->

to display the System Configuration menu.

24 Megabit Modem CRA-C User Manual

Configure and View Status

play

3 Do the following for each system setting option you want

to change:



Type the number of the option you want to configure.



Type the appropriate information for each option as indicated

ENTER

in Table 7 then press

Table 7. System Configuration Options

Type No.

1 Change

2 Change

3 Change

4 Factory

For Option Function

Type the new time in the 24-hour clock format

System Time

System Date

Password

Default Configuration

hh:mm:ss at the prompt. The new time shows in the upper right corner of the screen.

Type the month, day, and year in the mm/dd/yy format at the prompt. The new date shows in the upper left corner of the screen.

Enter a maximum of ei password, do the following:



Type password, press ENTER dis

ENTER



When prompted Please enter the new password, t

ENTER

each character of the password.



When prompted Please retype the password, t

ress

Password accepted.

If you change the default password, write it down and save it in a secure place. You cannot recover the password if it is forgotten.

Resets all ADSL transceiver and Ethernet brid to default. After

ou will reset these values. Select either N (no) or

that

es) to reset. When you select Y, the modem

Y ( restarts. Press the s You must then lo Ethernet brid including the password.

ht characters. To enter a new

and the message Creating user

s. Press

e the new password then press

. An * appears on the screen as you type

e the new password again then

ENTER

. You get this confirmation:

e values

ou type

, a message warns you

acebar several times to autobaud.

in again. All ADSL transceiver and

e values are now at default values,

Megabit Modem CRA-C User Manual 25

Configure and View Status

Configure the ADSL Transceiver

The ADSL menu provides access to set ADSL configuration parameters and to view ADSL performance and alarm status (menu options 1 through 4). See "View Status" (page 41) for more information on options 1 through 4.

Configure parameters for ADSL data transmission in the "Configuration" section that follows. Then, reset the Megabit Modem CRA-C to make the changes effective using the "Reset the ADSL Transceiver" section (page 29).

From the Main Menu, type

07/02/97 PAIRGAIN TECHNOLOGIES 08:44:57 ATU-C ADSL MEGABIT MODEM TERMINAL 01.01

ADSL MENU

1. ADSL PERFORMANCE STATUS

2. 24 HOUR ADSL PERFORMANCE HISTORY

3. 7 DAY ADSL PERFORMANCE HISTORY

4. ADSL ALARM HISTORY

5. ADSL TRANSCEIVER CONFIGURATION MENU

6. FULL ADSL RESET

7. SESSION ADSL RESET

(M)ain

ENTER CHOICE-->

to display the ADSL Menu.

Configuration

Configure ADSL transmission parameters for the Megabit Modem CRA-C (ATU-C) only. The Megabit Modem CRA (ATU-R) uses the parameters specified for the Megabit Modem CRA-C.

Press

Configuration Menu.

05/05/98 PAIRGAIN TECHNOLOGIES 08:51:00 ATU-C ADSL MEGABIT MODEM TERMINAL 01.01

ADSL CONFIGURATION MENU

1. STARTUP OPTION SESSION STARTUP

2. MAX UP DATA RATE 1080

3. MAX DOWN DATA RATE 3168

4. STARTUP SNR MARGIN 6dB

5. MARGIN THRESHOLD 4

6. ES THRESHOLD 100

7. ALARM CONFIGURATION LOF=E MAR=E ES=E SES=E SELF=E

8. TRANSMIT SPECTRUM STANDARD

(C)onfirm (U)ndo (R)eturn (M)ain

ENTER CHOICE-->

26 Megabit Modem CRA-C User Manual

at the ADSL Menu to display the ADSL

Configure and View Status

Do the following for each system setting option you want

to change:

Type the number of the option you want to configure.

•

Select, using the spacebar, or type the appropriate

•

information for each option as indicated in Table 8 then press

ENTER

After you type

transceiver, you are prompted

(Y/N)?

Type Y for yes or N for no. You then return to the

or M and have made changes to the ADSL

Save current settings

ADSL Menu.

Table 8.

ADSL Transceiver Options

Type No.

2* Max Up

For Option

1 Startup

Option

Data Rate

Function

Select one of three startup options using the spacebar. The unit uses the option you select to achieve a transmission rate for the ADSL line at a reboot or if the line is dropped and recovered.

Full startup always

where it will set a transmission rate up to the maximum specified in options 2 and 3 for maximum upstream and downstream data rate. It determines this rate by assessing the signal quality data (line length and noise conditions, for example) and the SNR value set in option 4 for SNR startup margin. It then uses the highest available rate based on this information.

Session startup

full startup to achieve a transmission rate, rather than re-assessing the signal quality data. In this mode, the system performs a session startup upon every powerup or reset and would also revert back to a full startup attempt when a session startup is not successful for 30 seconds. This is the default.

Fixed data rate

rates that you select in options 2 and 3 for maximum upstream and downstream data rates. The system attempts to come up at the programmed data rates with a margin greater than or equal to the configured margin. If the data rates cannot be obtained, then the system will continue to attempt the data rate. If it does not achieve it, sync will not occur.

Select a maximum data rate for the upstream channel (from subscriber to service provider). Use the spacebar to scroll through the available rates.

- System will always attempt a full startup

- Session startup uses the data acquired during a

- At startup, the system attempts only the data

(continued)

Megabit Modem CRA-C User Manual 27

Configure and View Status

ADSL Transceiver Options (continued)

Type

Table 8.

For Option Function

No.

3* Max Down

Data Rate

4 Startup SNR

Margin

5 Margin

Threshold

6 ES Threshold

7 Alarm

Configuration

8 Transmit

Spectrum

* Certain data rate combinations are invalid. If such a combination is selected in fixed

data mode, the modem will change the rates to a valid combination. When such a combination is selected in full startup mode, the modem accepts it, but the actual data rate to be achieved will not match the setting regardless of the line quality.

Select a maximum data rate for the downstream channel (from service provider to subscriber). Use the spacebar to scroll through the available rates.

Press the spacebar to select a startup SNR margin from –3 to 9 dB or NA (don't care about startup SNR margin). The default is 6 dB.

Type a dB value from 0 to 15. The Margin Threshold, in dB, is the excess SNR relative to the SNR at 10

-7

BER operation. When the margin falls below the threshold, this causes an SNR margin alarm and the MAR LED on the front panel to blink. The default value is 4.

Type in a value from 0 to 255 for the ES (errored second) Threshold. If the current 15-minute interval ES exceeds the set value, then this causes an ES alarm. The default is 100.

Configure each alarm as either major or minor alarm or disable the alarm. Enabling alarms affects the ADSL STAT LED, but not the alarm history. The available options for each alarm are (E) for enabled minor alarm, (D) for disabled alarms, and (M) for enabled major alarm.

Type

then press

until you highlight the alarm you

want to configure. Press the spacebar to toggle among the

ENTER

choices listed above and press

to select.

When you disable an alarm, it affects the system ALARM/STATUS LED or alarm relays, but it does not affect the reporting of alarm information in the menu displays.

Select downstream power option of either STANDARD (default) or HI-PERFORMANCE. Unit uses the selected option to set the upper limit of the downstream power spectral density (PSD) during data transmission. PSD for STANDARD is set to -40 dBm/Hz. PSD for HI-PERFORMANCE is set to -34 dBm/Hz for frequencies higher than 220 kHz.

28 Megabit Modem CRA-C User Manual

Configure and View Status

Reset the ADSL Transceiver

When you change any of the options 1 through 4 at the ADSL Menu, Reset the ADSL transceiver to make the changes effective and re-establish the ADSL link.

07/02/97 PAIRGAIN TECHNOLOGIES 08:44:57 ATU-C ADSL MEGABIT MODEM TERMINAL 01.01

ADSL MENU

1. ADSL PERFORMANCE STATUS

2. 24 HOUR ADSL PERFORMANCE HISTORY

3. 7 DAY ADSL PERFORMANCE HISTORY

4. ADSL ALARM HISTORY

5. ADSL TRANSCEIVER CONFIGURATION MENU

6. FULL ADSL RESET

7. SESSION ADSL RESET

(M)ain

ENTER CHOICE-->

Type either Table 9 describes the Reset options.

from the ADSL Menu to Reset the ADSL transceiver.

Table 9. Reset ADSL Transceiver Options

Type

For Option Function

No.

6 Full ADSL

Reset

7 Session ADSL

Reset

Megabit Modem CRA-C User Manual 29

Select this option to reset and set a transmission rate up to the maximum specified in options 2 and 3 of the ADSL Transceiver Configuration Menu. It determines this rate by assessing the signal quality data (line length and noise conditions, for example) and the SNR value set in option 4 of the ADSL Transceiver Configuration Menu.

Select this option to reset and use the data rates acquired during the previous full startup rather than re-assessing the signal quality data and determining new rates.

Configure and View Status

Configure the Bridge/Router

This section describes how to configure the Ethernet interface (bridge) of the modem as either a bridge or a router. Then, configure the management protocol options through the SNMP Configuration menu.

On the Main Menu, type

07/02/97 PAIRGAIN TECHNOLOGIES 08:55:55 ATU-C ADSL MEGABIT MODEM TERMINAL 01.01

BRIDGE/ROUTER MENU

----------------------------------------------------------ETHERNET MAC ADDRESS: 00-20-A7-20-68-F2 10 BASE-T LINK STATUS: LINK UP EBM STATUS: READY

----------------------------------------------------------SELECTIONS 1. BRIDGE/ROUTER CONFIGURATION

2. SNMP CONFIGURATION

3. STATISTICS

----------------------------------------------------------SETTINGS 4. RESET

(M)ain ENTER CHOICE-->

to display the Bridge/Router Menu.

The Bridge/Router Menu shows the MAC address for the unit you are viewing and current 10BASE-T and Ethernet Bridge Mode link status. See "View Status" (page 41) for more information on the Statistics menu.

Through the Bridge/Router Configuration menu, you can configure the Megabit Modem as either a bridge to forward Ethernet data based on MAC addresses or as a router to route Ethernet data based on IP addresses. You must configure both Megabit Modems (local and remote) with the same mode (both as bridges or both as routers).

Bridge mode can be a less secure method of sending data because the desired MAC address is broadcast over the network, but it allows protocols other than IP to be forwarded. Router mode provides security by statically mapping route entries. Routing can prevent eavesdropping and provide broadcast filtering. Select either the "Configure as a Bridge" section (page 31) or the "Configure as a Router" section (page 34).

After you change Bridge/Router Configuration or the SNMP Configuration options, "Reset the Ethernet bridge" (page 40) to make the changes effective.

30 Megabit Modem CRA-C User Manual

Configure and View Status

Configure as a Bridge

Configure Bridge parameters at the Bridge/Router Menu. Bridge configuration options are maintained and restored through the system's local service port and are kept in NVRAM to be used in subsequent initializations.

1 Type

2 Type

07/02/97 PAIRGAIN TECHNOLOGIES 08:54:11 ATU-C ADSL MEGABIT MODEM TERMINAL 01.01

BRIDGE CONFIGURATION MENU

------------------------------------------------------------SETTINGS 1. BRIDGE/ROUTER MODE BRIDGE

2. LOCAL IP ADDR 192.168.240.10

3. LOCAL SUBNET MASK 255.255.255.0

4. BOOT ROUTER IP ADDR 0.0.0.0

5. DEFAULT ROUTER IP ADDR 192.168.240.1

6. SPANNING TREE DISABLE

7. BOOT SERVER IP ADDR 0.0.0.0

8. BOOT MODE LOCAL

9. IMAGE FILE NAME A. IMAGE LOAD MODE LOCAL B. PACKET ENCAPSULATION HDLC

--------------------------------------------------------------

at the Bridge/Router Menu to display the Bridge

Configuration Menu.

, press the spacebar to toggle to Bridge, then press

ENTER

. At the prompt, Save current setting (Y/N), type

Y to display this screen. Ensure the mode setting is Bridge.

(C)onfirm (U)ndo (R)eturn (M)ain

ENTER CHOICE-->

3 Do the following for each Bridge Configuration option you want

to change:



Type the number or letter of the option you want to configure.



Select, using the spacebar, or type in the appropriate information for each option as indicated in Table 10

ENTER

then press

Megabit Modem CRA-C User Manual 31

ENTER

Configure and View Status

Bridge Configuration

Type

Table 10.

For Option Function

No.

2 Local IP Addr Configure for the modem to respond to an application

that uses IP protocol including SNMP and TFTP. The default is 0.0.0.0. You can either type in the address supplied by a system administrator or get the IP address via the boot server when boot mode is set to Network.

3 Local Subnet

Mask

4 Boot Router

IP Addr

5 Default Router

IP Addr

6 Spanning Tree Select either Enable or Disable (default) for

7 Boot Server IP

Addr

8 Boot Mode Select either Local (default) or Network for how the

Determines if a host (TFTP server, SNMP management station, or trap receiver) is on the same local subnet. If it is, the modem sends messages directly to the host. If it is not, the Megabit Modem CRA-C sends messages through a default router. The default is 255.255.255.0

Sets the IP address of the Boot Router used to forward BOOTP requests to the proper BOOTP server. When configured, the modem sends its BOOTP requests directly to this device rather than sending a broadcast packet. The default is 0.0.0.0.

Sets the address of the router which must be used to reach a host (TFTP server, SNMP management station, or trap receiver) located on another network. The default is 0.0.0.0.

Spanning Tree mode. Type the IP address of the TFTP server. The default is

the value of the BOOTP server if you have not configured a different TFTP server address on the BOOTP configuration file.

Megabit Modem CRA-C learns its protocol and network configuration (boot information) during power on or reset. Local Boot configuration is contained in NVRAM. When Network is selected, the Megabit Modem CRA-C learns its configuration over the network via a BOOTP server. It is recommended that the BOOTP server be connected to the same segment as the Megabit Modem CRA-C 10BASE-T port.

(continued)

32 Megabit Modem CRA-C User Manual

Configure and View Status

Table 10.

Type

For Option Function

No.

9 Image File

Name

A Image Load

Mode

Bridge Configuration (continued)

Read-only value. This parameter can be configured only in the BOOTP configuration file and is acquired when Boot Mode and Image Load Mode are set to network. This name must match the name of a file on the TFTP server in order for an image file download to occur.

Specifies how the operational image code is loaded for the Ethernet bridge. The Megabit Modem CRA-C supports both local and remote loading. Local image code is contained in flash devices for local loading of operation code. When loading over the network, use BOOTP (RFC 951) and TFTP (RFC 783) to obtain image files.

Set Local (default) to load the image file from the application sector of the Megabit Modem CRA-C non-volatile device, if valid. The code is valid if the CRC calculated on power-up matches the expected CRC. If it does not, the Megabit Modem CRA-C attempts to get a new image using the TFTP.

Set Network (with local backup) to attempt to download the image file over the network. It first issues a BOOTP request to get the image filename and image server IP address, then it initiates a TFTP session. If the BOOTP fails, the TFTP fails, or the downloaded image is invalid, the image file is loaded using the local image mode.

If no image is loaded after cycling through the TFTP process at least five times, the Megabit Modem CRA-C resets and repeats the process.

B Packet

Encapsulation

Megabit Modem CRA-C User Manual 33

Indicates the format used to encapsulate the Ethernet packets over ADSL. Choices are HDLC (default) and PPP.

Configure and View Status

Configure as a Router

Configure Router parameters at the Bridge/Router Menu. Router configuration options are maintained and restored through the system's local service port and are kept in NVRAM to be used in subsequent initializations.

1 Type

07/02/97 PAIRGAIN TECHNOLOGIES 08:54:33 ATU-C ADSL MEGABIT MODEM TERMINAL 01.01

BRIDGE/ROUTING CONFIGURATION MENU

--------------------------------------------------------------MODE SETTING 1. BRIDGE/ROUTER MODE ROUTER IP STATIC ROUTING DESTINATION SUBNET MASK GATEWAY ADDRESS TABLE 2. DEFAULT 192.168.240.1

3. 192.168.242.0 255.255.255.0 172.16.100.2

4. 0.0.0.0 0.0.0.0 0.0.0.0

5. 0.0.0.0 0.0.0.0 0.0.0.0 LAN PORT CONF. 6. LAN IP ADDR: 192.168.240.10

7. LAN SUBNET MASK: 255.255.255.0 LINE PORT CONF. 8. LINE IP ADDR: 172.16.100.1

9. LINE SUBNET MASK: 255.255.255.0 OTHER CONF. A. BOOT SERVER IP ADDR: 0.0.0.0 B. BOOT MODE: LOCAL C. IMAGE FILE NAME: D. IMAGE LOAD MODE: LOCAL E. PACKET ENCAPSULATION: HDLC

-------------------------------------------------------------- C(o)nfirm (U)ndo (R)eturn (M)ain ENTER CHOICE-->

at the Bridge/Router Menu to display the

Bridge/Routing Configuration Menu.

2 Type

ENTER

, press the spacebar to toggle to Router, then press

. At the prompt,

Save current setting (Y/N)

, type Y to display the screen below. Ensure the mode setting is Router. The following screen shows configuration for a Megabit Modem CRA-C (ATU-C) routed toward a remote Megabit Modem CRA (ATU-R), using IP addresses from the example in Figure 12.

34 Megabit Modem CRA-C User Manual

Configure and View Status

The following screen shows configuration for a Megabit Modem CRA (ATU-R) routed toward a Megabit Modem CRA-C (ATU-C), using IP addresses from the example in Figure 12.

07/02/97 PAIRGAIN TECHNOLOGIES 08:54:33 ATU-R ADSL MEGABIT MODEM TERMINAL 01.01

BRIDGE/ROUTING CONFIGURATION MENU

--------------------------------------------------------------MODE SETTING 1. BRIDGE/ROUTER MODE ROUTER IP STATIC ROUTING DESTINATION SUBNET MASK GATEWAY ADDRESS TABLE 2. DEFAULT 172.16.100.1

3. 0.0.0.0 0.0.0.0 0.0.0.0

4. 0.0.0.0 0.0.0.0 0.0.0.0

5. 0.0.0.0 0.0.0.0 0.0.0.0 LAN PORT CONF. 6. LAN IP ADDR: 192.168.242.1

7. LAN SUBNET MASK: 255.255.255.0 LINE PORT CONF. 8. LINE IP ADDR: 172.16.100.2

9. LINE SUBNET MASK: 255.255.255.0 OTHER CONF. A. BOOT SERVER IP ADDR: 0.0.0.0 B. BOOT MODE: LOCAL C. IMAGE FILE NAME: D. IMAGE LOAD MODE: LOCAL E. PACKET ENCAPSULATION: HDLC

-------------------------------------------------------------- C(o)nfirm (U)ndo (R)eturn (M)ain ENTER CHOICE-->

3 Do the following for each Router Configuration option you want

to change:



Type the number or letter of the option you want to configure.



Select, using the spacebar, or type in the appropriate information for each option as indicated in Table 11 then

ENTER

press

Megabit Modem CRA-C User Manual 35

Configure and View Status

Table 11.

Type No.

For

Function

Option

2 Default Contains the address of the default gateway 3

IP Static

Routing

Table

6 LAN IP

Addr

7 LAN Subnet

Mask

8 Line IP

Addr

9 Line Subnet

Mask

Consists of the Destination, Subnet Mask, and Gateway. Must be configured for the Megabit Modem CRA-C to operate as a static IP router. 0.0.0.0 is the format for each field and the default.

Input the network address of the Megabit Modem CRA-C 10BASE-T port. It is necessary for static IP mapping to function properly. 0.0.0.0 is the format for the field.

Input the subnet mask of the Megabit Modem CRA-C 10BASE-T port. Necessary for static IP mapping to function properly. 0.0.0.0 is the format for the field.

255.255.255.0 is the default. Input the network address of the Megabit Modem

CRA-C ADSL port. Necessary for static IP mapping to function correctly.

Input the subnet of the Megabit Modem CRA-C ADSL port. Necessary for static IP mapping to function correctly. 255.255.255.0 is the default.

Router Configuration

A Boot Server

IP Addr

B Boot Mode Describes the manner in which the Megabit Modem

36 Megabit Modem CRA-C User Manual

Gives the address of the TFTP server. The default is the value of the BOOTP server if you have not configured a different TFTP server address on the BOOTP configuration file.

CRA-C learns its protocol and network configuration during power-on or reset. Supports both local and remote loading of Boot information (IP configuration only). Local Boot configuration is contained in NVRAM. The Megabit Modem CRA-C obtains its configuration using values found in NVRAM when Local (the default) is selected. When Network is selected, the Megabit Modem CRA-C learns its configuration over the network via a BOOTP server.

(continued)

Configure and View Status

Type

For Option Function

No.

C Image File

Name

D Image Load

Mode

Table 11.

Router Configuration (continued)

Read-only parameter. The name must match the name of a file on the TFTP server for an image file download to occur.

ecifies how the Ethernet bridge code is loaded. The

abit Modem CRA-C supports both local and remote

. Local image code is contained in flash devices

loadin for local loadin the network, use BOOTP (RFC 951) TFTP (RFC 783) to obtain ima

Set Local (default) to load the ima

lication sector of the Megabit Modem CRA-C

a non-volatile device, if valid. The code is valid if the CRC calculated on CRC. If it does not, the Me

ts to get a new image via the TFTP.

attem Set Network (with local backu

the ima

uest to get the image filename and image server IP

re address, then it initiates a TFTP session. If the BOOTP fails, the TFTP fails, or the downloaded ima invalid, the ima mode.

If no image is loaded after cycling through the TFTP process at least five times, the Megabit Modem CRA-C resets and repeats the process.

of operation code. When loading over

e files.

e file from the

ower-up matches the expected

abit Modem CRA-C

) to attempt to download

e file over the network. It first issues a BOOTP

e file is loaded using the local image

e is

E Packet

Encapsulation

Megabit Modem CRA-C User Manual 37

Indicates the encapsulation format used to envelope the Ethernet packets over ADSL. Choices are HDLC (default) and PPP.

Configure and View Status

Configure SNMP

Configure SNMP parameters and trap addresses at the SNMP Configuration menu.

1 Type

07/02/97 PAIRGAIN TECHNOLOGIES 08:53:26 ATU-C ADSL MEGABIT MODEM TERMINAL 01.01

SNMP CONFIGURATION MENU

---------------------------------------------------------------

SETTINGS 1. SNMP READ ONLY COMM STRING: public

2. SNMP READ WRITE COMM STRING: private

3. AUTHENTICATION TRAP STATUS: ENABLE

4. TRAP RECEIVER 1 IP ADDRESS: 0.0.0.0

5. TRAP RECEIVER 1 COMM STRING: public

6. TRAP RECEIVER 2 IP ADDRESS: 0.0.0.0

7. TRAP RECEIVER 2 COMM STRING: public

---------------------------------------------------------------

(C)onfirm (U)ndo (R)eturn (M)ain

ENTER C HOICE-->

at the Bridge/Router Menu to display the SNMP

Configuration Menu.

2 Do the following for each SNMP Configuration option you want

to change:



Type the number of the option you want to configure.



Select, using the spacebar, or type in the appropriate information for each option as indicated in Table 12 then

ENTER

press

38 Megabit Modem CRA-C User Manual

Configure and View Status

Table 12.

SNMP Configuration Options

No. For Option Function

1 SNMP Read

Only Comm String

2 SNMP Read

Write Comm String

3 Authentication

Trap Status

Provides the authentication string used for SNMP read-only operations. At the prompt

COMMUNITY STRING:

community string. Typically, use either Public or Private. The read-only community string setting must match the network manager community string setting of Public or Private. The authentication string is required for the Megabit Modem CRA-C to correctly respond to SNMP set and get requests.

Provides the authentication string used for SNMP read-write operations. At the prompt

COMMUNITY STRING:

or Private. The read-write community string setting must match the network manager community string setting of Public or Private. The authentication string is required for the Megabit Modem CRA-C to correctly respond to SNMP set and get requests

Select Disable (default) or Enable for use of authentication error trap generation. The trap is sent to the trap receiver address when an SNMP request is received with an invalid or incorrect community string.

NEW

, type in appropriate

NEW

, type either Public (default)

4 Trap Receiver

1 IP Address

5 Trap Receiver

1 Comm String

Sets the first IP address for the server receiving the trap.

Enter the first string used for trap authentication is entered. Trap Receiver 1 Community String is blank if no trap is being used. The field is case sensitive.

6 Trap Receiver

2 IP Address

7 Trap Receiver

2 Comm String

Megabit Modem CRA-C User Manual 39

Enter the second IP address for the server receiving the trap.

Enter the second string used for trap authentication. Trap Receiver 2 Community String is blank if no trap is being used. The field is case sensitive

Configure and View Status

Reset the Ethernet Bridge

Changes you make to the Ethernet bridge through the Bridge/Router Configuration menus (pages 31 and 37) and SNMP Configuration menu (page 38) write immediately to flash memory when changes are confirmed. However, they do not take effect until the Megabit Modem CRA-C Ethernet bridge is reset. The Reset option causes the bridge to reboot with the new configuration.

Reset the Megabit Modem CRA-C Ethernet bridge:

1 Type

07/02/97 PAIRGAIN TECHNOLOGIES 08:55:55 ATU-C ADSL MEGABIT MODEM TERMINAL 01.01

BRIDGE/ROUTER MENU

----------------------------------------------------------ETHERNET MAC ADDRESS: 00-20-A7-20-68-F2 10 BASE-T LINK STATUS: LINK UP EBM STATUS: READY

----------------------------------------------------------SELECTIONS 1. BRIDGE/ROUTER CONFIGURATION

2. SNMP CONFIGURATION

3. STATISTICS

----------------------------------------------------------SETTINGS 4. RESET

at the Main Menu to display the Bridge/Router menu.

(M)ain ENTER CHOICE--> WARNING: This will bring down all connections. Are you sure? (Y/N)

2 Make all changes in the Bridge/Routing Configuration menu and

the SNMP Configuration menu.

3 Type

to select Reset.

4 Type either Y for yes to Reset or N for no to cancel Reset.

When you select Y to Reset, the Megabit Modem CRA-C Ethernet link is dropped, the bridge is reset, then the Ethernet link is re-established. The changes made to the Ethernet bridge are now effective.

40 Megabit Modem CRA-C User Manual

Configure and View Status

View Status

This section describes status menus. You can view information such as current alarm status, performance history, and product information. See the following section for:



system information (page 41)



ADSL transceiver status (page 42)



Ethernet bridge statistics (page 48)

System Information

The System Information screen provides general product information for the units at both the service provider (ATU-C) and subscriber (ATU-R) sites. This includes hardware and software revision information as well as the product number and manufacturing information.

Access the System Information screen by typing

typing

on the System Status and Configuration menu to display the System

Information screen.

on the Main Menu then

07/02/97 PAIRGAIN TECHNOLOGIES 08:43:44 ATU-C ADSL MEGABIT MODEM TERMINAL 01.01

SYSTEM INFORMATION

ATU-C ATU-R MODEM PRODUCT NUM 1704-01 1704-02 HARDWARE REV P00 P00 MANUF DATE 01/01/96 01/01/96 SERIAL NUM 000000000000 000000000000 SOFTWARE REV 01.01 01.01 PROM CHECKSUM 5D7D/1038 300C/AFF9 TRANSCEIVER HARDWARE NUM 1752-01 1764-01 HARDWARE REV P00 P00 BRIDGE MODULE SOFTWARE REV V2.22 V2.22 PROM CHECKSUM 1234 1234 HISTORY DAY IN OPERATION 4 4

(R)eturn (M)ain

ENTER CHOICE-->

Megabit Modem CRA-C User Manual 41

Configure and View Status

ADSL Transceiver Status

From the Main Menu, type

07/02/97 PAIRGAIN TECHNOLOGIES 08:44:57 ATU-C ADSL MEGABIT MODEM TERMINAL 01.01

ADSL MENU

1. ADSL PERFORMANCE STATUS

2. 24 HOUR ADSL PERFORMANCE HISTORY

3. 7 DAY ADSL PERFORMANCE HISTORY

4. ADSL ALARM HISTORY

5. ADSL TRANSCEIVER CONFIGURATION MENU

6. FULL ADSL RESET

7. SESSION ADSL RESET

(M)ain

ENTER CHOICE-->

Select options 1 through 4 to view status for the ADSL transceiver. The ADSL ES counts, UAS counts, and minimum SNR margins are updated every second and can be viewed from the ADSL Performance History screens shown on pages 43 through 47.

to display the ADSL Menu.

42 Megabit Modem CRA-C User Manual

Configure and View Status

ADSL Performance Status. The ADSL Performance Status screen is updated every second and provides a summary of the ADSL parameters and outstanding ADSL-related alarms. This screen displays the upstream and downstream ADSL links. The SNR (signal-to-noise ratio) margin column displays both the current SNR margins as well as the minimum SNR margins for the current 24-hour period.

Press

on the ADSL Menu to display the ADSL Performance Status screen.

07/02/97 PAIRGAIN TECHNOLOGIES 08:45:10 ATU-C ADSL MEGABIT MODEM TERMINAL 01.01

ADSL PERFORMANCE STATUS

DOWN ALARMS: NONE UP ALARMS: NONE SYSTEM STATE: DATA

DOWNSTREAM UPSTREAM

---------- ------- cur/min cur/min

SNR MARGIN (dB): 13.1/13.1 7.6/7.6 LINE ATTN -0.1 -0.7 24 HOUR ES: 3 3 24 HOUR UAS: 38 38 DATA RATE (kbps): 3168 1080

(C)lear (R)eturn (M)ain

EN TE R C HO ICE-->

Do not type

unless you want to clear the ADSL performance and alarm counters in both the local and remote units.

Type

to clear the ADSL performance and alarm counters. This also clears

the counts in the remote Megabit Modem CRA. Table 13 describes the ADSL Performance Status screen fields.

Megabit Modem CRA-C User Manual 43

Configure and View Status

Table 13.

ADSL Performance Status Screen Fields

Field Meaning

Down Alarms Identifies the current alarms in the path to the subscriber. Up Alarms Identifies the current alarms in the path from the subscriber. System State Describes the state of the ADSL system.

Startup states:

DATA (normal operation) HAND (handshake) TRAIN (training transceivers for loop conditions) WSYNC (waiting for frame synchronization)

SNR Margin (dB) Identifies the current (cur) and minimum (min) margin values

for the ADSL loop for the current 24-hour period. The SNR margin represents the margin relative to the SNR required for a BER of 10 performance better than 10 margin of 6 dB, which translates to a performance of 10 BER or better. See page 2 for information on SNR margin and BER.

Line Attn (dB) Indicates the decrease in amplitude of the transmitted

upstream and downstream signals as measured at the ADSL respective receivers for that channel (upstream or downstream).

–7

. A margin greater than zero indicates a

–7

. The system provides a default

–10

24 Hour ES Indicates the total number of ES that have been detected on the

ADSL link during the previous 24-hour period.

24 Hour UAS Indicates the total number of unavailable seconds (UAS) that

have been detected on the ADSL link during the previous 24-hour period. This figure represents the amount of time that the lines were not available for transmission since power on or last clear.

Data Rate (kbps) Identifies the actual data rates of the ADSL link.

44 Megabit Modem CRA-C User Manual

Configure and View Status

24 Hours ADSL Performance History. The 24 Hour ADSL Performance History report consists of eight screens. Each screen displays three hours of data, providing a 24-hour report in 15-minute increments.

Type

on the ADSL menu to open the 24 Hour ADSL Performance

History screen.

07/02/97 PAIRGAIN TECHNOLOGIES 08:45:54 ATU-C ADSL MEGABIT MODEM TERMINAL 01.01

24 HOUR ADSL PERFORMANCE HISTORY (errored seconds/unavailable seconds/snr)

DOWNSTREAM UPSTREAM 08:45 000/000/ 13.1 000/000/ 7.6 08:30 000/000/ 13.1 000/000/ 7.6 08:15 000/000/ 13.1 000/000/ 7.6 08:00 000/000/ 13.1 000/000/ 7.6 07:45 000/000/ 13.1 000/000/ 7.6 07:30 000/000/ 13.1 000/000/ 7.6 07:15 000/000/ 13.1 000/000/ 7.6 07:00 000/000/ 13.1 000/000/ 7.6 06:45 000/000/ 13.1 000/000/ 7.6 06:30 000/000/ 13.1 000/000/ 7.6 06:15 000/000/ 13.1 000/000/ 7.6 06:00 000/000/ 13.1 000/000/ 7.6

(C)lear (P)revious (N)ext (R)eturn (M)ain

ENTER CHOICE-->

Type

to clear all ES, UAS counts, including the equivalent counts in the

remote unit. The minimum SNR for the period is reset to the current SNR.

The 24 Hour ADSL Performance History data is lost when the Megabit Modem CRA-C is turned off.

Megabit Modem CRA-C User Manual 45

Configure and View Status

7 Days ADSL Performance History. The 7 Day ADSL Performance History menu displays the ES and UAS counts, and the minimum SNR margins for the previous 6 days and the current day. The division of the intervals is based on 12 am midnight as the dividing boundary, and the current day count is not necessarily equal to the total count for the past 24 hours.

Type

on the ADSL Menu to open the 7 Day ADSL Performance

History menu.

07/02/97 PAIRGAIN TECHNOLOGIES 08:46:07 ATU-C ADSL MEGABIT MODEM TERMINAL 01.01

7 DAY ADSL PERFORMANCE HISTORY

(errored seconds/unavailable seconds/snr)

DOWNSTREAM UPSTREAM 07/02/97 00000/00000/ 13.1 00000/00000/ 7.6 07/01/97 00003/00038/ 13.1 00003/00038/ 7.6 06/30/97 00000/00000/ NA 00000/00000/ NA 06/29/97 00000/00000/ NA 00000/00000/ NA 06/28/97 00000/00000/ NA 00000/00000/ NA 06/27/97 00000/00000/ NA 00000/00000/ NA 06/26/97 00000/00000/ NA 00000/00000/ NA

(C)lear (R)eturn (M)ain

ENTER CHOICE-->

Type

to clear all ES and UAS counts, including the equivalent counts in

the remote unit. The minimum SNR for the period is reset to the current SNR.

The 7 Day ADSL Performance History data is lost when the Megabit Modem CRA-C is turned off.

46 Megabit Modem CRA-C User Manual

Configure and View Status

ADSL Alarm History. The ADSL Alarm History screen consists of five columns. Table 14 describes the information found in each column.

Type

on the ADSL Menu to open the ADSL Alarm History screen.

09/08/97 PAIRGAIN TECHNOLOGIES 08:47:54 ATU-C ADSL MEGABIT MODEM TERMINAL 01.01

ADSL ALARM HISTORY

Type First Last Current Duration(s)

LOF, DOWN 09/08/97-16:50:46 09/08/97-17:53:20 OK LOF, UP 09/08/97-16:50:46 09/08/97-17:53:20 OK MARGIN, DOWN OK MARGIN, UP OK ES, DOWN OK ES, UP OK SES, DOWN OK SES, UP OK SELFTEST OK

LAST CLEARED: 09/08/97-16:50:45

(C)lear (R)eturn (M)ain

ENTER CHOICE-->

to update the first and last date/time stamps and clear the time to 0.

The Alarm History data is lost when the Megabit Modem CRA-C is turned off.

Table 14.

ADSL Alarm History Screen Columns

Name Description

Type Identifies local, remote, and ADSL link alarms.

LOF: Loss of frame failure MARGIN: Low SNR margin alarm ES: Excessive errored seconds SES: Severely errored seconds

SELF: Self test First Lists the first time an alarm is detected. Last Lists the last time an alarm was detected. Current Identifies the current status of the alarm. Durations Indicates the total accumulated number of seconds the

system was in alarm condition since the last clear.

Megabit Modem CRA-C User Manual 47

Configure and View Status

Ethernet Bridge Statistics

The Megabit Modem CRA-C provides real-time, non-disruptive monitoring of system performance. This menu displays a count of the valid Ethernet and ADSL frames received and forwarded by the 10BASE-T MDI-X and the line ports, respectively. The display is updated every 10 seconds and whenever you access this menu.

Access the Statistics screen for the bridge by typing

then typing

on the Bridge/Router Menu.

07/02/97 PAIRGAIN TECHNOLOGIES 08:55:07 ATU-C ADSL MEGABIT MODEM TERMINAL 01.01

BRIDGE STATISTICS MENU

----------------------------------------------------------ETHERNET PORT: INPUT FRAMES: 10443613 OUTPUT FRAMES: 5277712 DISCARDED FRAMES: 0 ERRORED FRAMES: 0

----------------------------------------------------------ADSL PORT: INPUT FRAMES: 5278375 OUTPUT FRAMES: 10437290 DISCARDED FRAMES: 0 ERRORED FRAMES: 0

---------------------------------------------------------- (R)eturn (M)ain ENTER CHOICE-->

on the Main Menu

Table 15 describes the Bridge Statistics fields.

48 Megabit Modem CRA-C User Manual

Configure and View Status

Table 15.

Bridge Statistics Fields

Field Definition

Ethernet Port

Input Frames The number of frames correctly received. Output Frames The number of frames correctly transmitted. Discarded Frames The number of frames dropped due to an overflow of the

input or output buffer for the port.

Errored Frames The number of frames received in error (CRC, alignment,

and dribbling bit) from the input buffer.

ADSL Port

Input Frames The number of frames correctly received. Output Frames The number of frames correctly transmitted. Discarded Frames The number of frames dropped due to an overflow of the

input or output buffer for the port.

Errored Frames The number of frames received in error (CRC, alignment,

and dribbling bit) from the input buffer.

Log Out

Log out from the Main Menu by pressing

Megabit Modem CRA-C User Manual 49

Configure and View Status

50 Megabit Modem CRA-C User Manual

NETWORK AND MANAGEMENT OVERVIEW

Through the console menus, you can configure the Megabit Modem CRA-C as a bridge to forward Ethernet data based on MAC addresses or as a router to route Ethernet data based on IP addresses. Additionally, you can configure parameters for management and encapsulation protocols using the Megabit Modem CRA-C console menus.

For information about this topic

MAC layer bridging and spanning tree protocol 51 Static IP routing 53 Management protocols 61 Network configuration and image code download 64 Encapsulation protocols 66

Go to page

MAC Layer Bridging and Spanning Tree Protocol

MAC Layer Bridging.

from a source to a destination at the link layer (of an OSI reference model). The information is sent to a physical address known as a Media Access Control (MAC) address.

The Megabit Modem CRA-C provides transparent Ethernet MAC level bridging. It is a completely self-contained bridge with a CPU, memory subsystems (RAM, Flash, etc.), an Ethernet controller and Ethernet drivers, and other glue logic. It provides complete main bridging tasks of learning, forwarding, filtering, and hashing/buffer management. Additionally, it offers

802.1d Spanning Tree protocol, packet encapsulation (via HDLC or PPP framing), and other local tasks.

Forwarding performance is at 2.7 kpps (kilo packets per second) and filtering performance is at full Ethernet rate of 14 kpps for 64-byte frames (minimum size).

A bridge moves information across an internetwork

Spanning Tree.

Spanning Tree protocol eliminates loops in a LAN topology by partitioning out redundant links between LAN segments. This ensures that there is only one path, or link, between any two nodes on the network. If this link goes down, Spanning Tree enables the partitioned links to create a new loop-free topology, if possible. An example of the active topology is shown in Figure 9.

Megabit Modem CRA-C User Manual 51

Network and Management Overview

Figure 9. Spanning Tree Topology

52 Megabit Modem CRA-C User Manual

Network and Management Overview

You can enable or disable Spanning Tree on the Bridge/Router Configuration Menu. The Megabit Modem CRA-C uses the Spanning Tree defaults shown in Table 16. These values are user-configurable through SNMP as part of the Spanning Tree group in RFC 1493.

Table 16.

Spanning Tree Defaults

Spanning Tree Attribute Default Value

ST Bridge Priority Hx0000 ST Max Age 30 seconds ST Hello Time 10 seconds ST Hold Time 10 second ST Forward Delay 10 second ST Port 1 Priority (LAN) 0 ST Port 2 Priority (ADSL) 0 ST Port Path Cost 1

Static IP Routing

Through the static IP routing feature, you can configure the Megabit Modem CRA-C as an IP router with statically programmed route entries. You can enable this function as a security feature to prevent eavesdropping and to provide broadcast filtering, as well as to specify multiple destination gateways. When static IP routing is enabled, you can access only specific remote IP subnets or hosts.

Since IP routers make forward or filter decisions based on the network-layer IP address instead of the MAC hardware address, MAC-level broadcast frames are prevented from reaching unwanted destinations in the network. The example in Figure 10 shows a simple Internet Service Provider (ISP) site that uses the static IP routing feature to filter MAC-level broadcast frames sourced by ISP Subscriber A from reaching ISP Subscriber B.

Megabit Modem CRA-C User Manual 53

Network and Management Overview

Figure 10.

54 Megabit Modem CRA-C User Manual

Simple Configuration for Static IP Routing

Network and Management Overview

Figure 11 shows a more complex example of multiple gateways that use static IP routing to route packets sourced from specific users to different destination gateways.

Figure 11.

Megabit Modem CRA-C User Manual 55

Multiple Gateways Specified for Static IP Routing

Network and Management Overview

When you configure the static IP routing feature, set the parameters defined in Table 17 through the Megabit Modem CRA-C console menus. Set the parameters defined in Table 18 in an external router (used as a gateway).

Table 17.

Megabit Modem CRA-C Static IP Routing Parameters

Parameter Definition

Bridge/Router Mode

Packet Encapsulation

Default Router IP Address

IP Static Routing Table

LAN IP Address and Subnet Mask

Line IP Address and Subnet Mask

Select router for the Megabit Modem CRA-C to route based on IP addresses. Both the Megabit Modem CRA-C and Megabit Modem CRA units connected via ADSL must be set to router mode.

Select either PPP or HDLC. PPP is the preferred encapsulation for routing when interfacing with non-PairGain equipment. HDLC is lower overhead and preferred when interfacing PairGain to PairGain equipment.

Specify the next hop default router entry. This entry tells Megabit Modem CRA-C what to do with a packet that has a destination address which is not in the Static IP Routing table.

Specify up to three static routes and one default route. The default route specifies where to send packets which do not match any of the other configured static routes.

Configure the IP address and the Subnet Mask for the 10BASE-T port. These must be configured for static IP mapping to function properly.

Configure the IP address and Subnet Mask for the ADSL WAN port

56 Megabit Modem CRA-C User Manual

Network and Management Overview

Table 18.

External Router Static Route Entry

Parameter Definition

Static Route Entry in External Routers

Configure a Static Route entry in any of the external routers which may have been specified as a Default Router or as a Gateway. This is required because the static IP routing feature does not send periodic route updates using protocols like Routing Information Protocol (RIP) or Open Shortest Path First (OSPF) so that other external routers can automatically update their routing tables. This implementation prevents other parties from discovering routes through eavesdropping. The format of this entry will vary among different router vendors, but it will typically be in the form of Destination, Mask, and Next Hop Gateway. Destination is the remote IP subnet or host address. Gateway is the IP address of the Megabit Modem CRA-C on the same subnet as the external router.

Megabit Modem CRA-C User Manual 57

Network and Management Overview

Figure 12 shows an example of a point-to-point ADSL system and hypothetical values of parameters defined in Tables 17 and 18.

Figure 12.

58 Megabit Modem CRA-C User Manual

Example for Static IP Routing

Network and Management Overview

Megabit Modem CRA-C IP Addresses

The Megabit Modem CRA-C has two IP addresses, one for the ADSL WAN port and one for the Ethernet port. In Figure 13, the non-shaded side of the provider and subscriber modems indicates the LAN address for the Ethernet (10BASE-T) connection. The shaded side of the provider and subscriber modems is the IP Line address for the ADSL line connection. Note that the IP Line address is unique from the LAN addresses. When connecting a Megabit Modem CRA-C and a Megabit Modem CRA point-to-point via ADSL, the IP Line addresses are completely isolated and hidden from the rest of the network. As a result, any valid IP address can be assigned to these ports but should be on the same subnet.

When routing, data travels one hop at a time. Figure 13 shows destination and next hop IP addresses. The destination address indicates the network and subnetwork of the next hop for a common network topology . The default gateway is the router to which datagrams are sent that do not have an assigned route in the static routing table.

Use Figure 13 as a worksheet to help you determine/record static IP routing addresses.

Megabit Modem CRA-C User Manual 59

Network and Management Overview

Figure 13.

60 Megabit Modem CRA-C User Manual

IP Addresses

Network and Management Overview

Management Protocols

SNMP is used for configuring system and bridge parameters, monitoring statistics, and performing advanced management.

SNMP

This management protocol specifies how to send information between a Network Management System (NMS) and managed devices on a network. Managed devices (such as the Megabit Modem CRA-C) run a program called an agent. The agent interprets SNMP requests and responds to them. The NMS communicates with the agents in the managed devices to:



set configuration



get configuration



get status

A Management Information Base (MIB) defines these configuration and status parameters. The Internet Engineering Task Force (IETF) specifies standard MIBs for certain types of devices, ensuring any NMS can manage them. Additionally, vendors can issue proprietary MIBs for their devices to fit specific needs.

Table 19 shows the Megabit Modem CRA-C SNMP configuration parameters that are maintained and restored through the local console port. These parameters are kept in the Megabit Modem CRA-C NVRAM and are parameters that must be configured for SNMP to work.

Megabit Modem CRA-C User Manual 61

Network and Management Overview

Table 19.

SNMP Configuration Default Values

Attribute Factory Default

Download Image File Name Not configurable via console Local IP Address 0.0.0.0 Local Subnet Mask 255.255.255.0 Boot Router IP Address 0.0.0.0 Default Router IP Address 0.0.0.0 Boot Server IP Address 0.0.0.0 Boot Mode (local, network) local Image Load Mode (local, network) local SNMP RO Community String public SNMP RW Community String private Trap Receiver 1 IP Address 0.0.0.0 Trap Receiver 1 Community String null string Trap Receiver 2 IP Address 0.0.0.0 Trap Receiver 2 Community String Null string Authentication Trap enable/disable disable ST Enable/disable disable

Megabit Modem CRA-C SNMP Agent

An agent is program resident in managed devices (for example, Megabit Modem CRA-C, modems, nodes, routers and hubs). Agents translate data into code the NMS can read. Agents and NMS communicate using SNMP as the transport mechanism. SNMP uses standard Internet Protocol (IP) to transport incoming and outgoing messages to the appropriate agent or NMS address. Each SNMP command requires an IP address or NMS from the agent to transport these messages.

62 Megabit Modem CRA-C User Manual

Network and Management Overview

The Megabit Modem CRA-C provides an SNMP agent that supports several MIBs for the management of the system. The SNMP agent can process datagrams received from both the Ethernet interface (LAN) and the ADSL interface (Line). The agent and the protocol stack complies with the following RFCs:

RFC 1155 Structure of Management Information (SMI)

•

RFC 1157 Simple Network Management Protocol (SNMP)

•

RFC 826 Address Resolution Protocol (ARP)

•

RFC 792 Internet Control Message Protocol (ICMP)

•

RFC 791 Internet Protocol (IP)

•

RFC 768 User Datagram Protocol (UDP)

•

MIB and Trap Support

Each managed device has configuration, status, and statistical information that defines its functionality and operational capabilities. These elements, together, are the MIB for the device being managed. The MIB defines the kind of information an NMS can retrieve from a managed device and the settings an NMS can control in a managed device.

Megabit Modem CRA-C supports the following MIBs:

RFC 1213 MIB II Management Information Base for Network

•

Management of TCP/IP-Based Internet:MIB-II supported groups: system, interfaces, IP, ICMP, UDP, and SNMP groups

RFC 1215 A Convention for Defining Traps for Use with the SNMP

•

supported objects: ColdStart, linkUp, linkDown, and authenticationFailure traps. Link status traps are sent for events related to Ethernet.

RFC 1493 Definition of Managed Objects for Bridges supported

•

objects: Base, Spanning Tree, and transparent bridging groups.

Megabit Modem CRA-C User Manual 63

Network and Management Overview

The Spanning Tree MIB can only be accessed if the Spanning Tree protocol is enabled.



PairGain REX MIB an enterprise specific MIB designed for the agent in the Megabit Modem CRA-C for managing the ADSL portion of the unit.



The Ethernet interface has the ifIndex value of 1 and the WAN (ADSL) interface has an ifIndex of 2.

Access any PairGain-specific MIBs through the Internet at ftp.pairgain.com. Use the following:

FTP ftp.pargain.com

•



use guest or your e-mail address as you user password



enter cd snmp/rex/mibs get pgrexmib.txt

•

Network Configuration and Image Code Download

BOOTP

BOOTP is used to supply network configuration information to Megabit Modem CRA-C from a BOOTP server. Used in conjunction with TFTP, you can use BOOTP to download image code. The Megabit Modem CRA-C initiates a BOOTP request in these situations:



current configuration sector is determined to be invalid; this can occur when the CRC of configuration sector does not match the expected CRC on power-up



user sets the value of Boot Mode to NETWORK, saves the configuration to flash, and then reboots the Megabit Modem CRA-C

64 Megabit Modem CRA-C User Manual

Network and Management Overview

BOOTP conforms to the following RFCs:



RFC 951: Bootstrap Protocol (BOOTP)



RFC 1533: DHCP Options and BOOTP Vendor Extensions



RFC 1542: Clarification and Extensions for the Bootstrap Protocol (updates 951)

A BOOTP request is broadcast through the Ethernet port to the local network. The request is not sent from the ADSL port because the boot sector does not contain the code necessary to transmit over the WAN link. If a BOOTP server is on the local network and is configured correctly, it returns a BOOTP response. Once the Megabit Modem CRA-C receives a BOOTP response, it keeps the IP address, boot server, default router, and any other information associated with the module in the configuration sector of the flash. Subsequent BOOTP responses for the Megabit Modem CRA-C are ignored.

When a BOOTP server is not on the local network, the request fails unless there is a BOOTP agent on the network that recognizes and forwards the request to the server. The BOOTP server does not contain an entry that corresponds to the MAC address of the Megabit Modem CRA-C.

From the console interface, you can configure network parameters and save them to flash so the BOOTP operation can be bypassed. The BOOTP server should be connected to the same segment as the Megabit Modem 10BASE-T port.

Megabit Modem CRA-C User Manual 65

Network and Management Overview

TFTP

Trivial File Transfer Protocol (TFTP) is used to download networking image code to the Megabit Modem CRA-C from a TFTP server. This allows software upgrades to be performed over the network. The Megabit Modem CRA-C initiates a TFTP download of application code in these situations:



current application code is not valid; this occurs when the CRC calculated on power-up doesn't match the expected CRC



user sets the value of Image Load Mode to NETWORK, save the configuration to flash, and reboots the Megabit Modem CRA-C

In either case, the Megabit Modem CRA-C performs a BOOTP request first to get the most current network configuration. If the BOOTP fails, the TFTP session is attempted.

TFTP conforms to RFC 1350: The TFTP Protocol (Revision 2) TFTP uses the connectionless User Datagram Protocol (UDP) for file transfer

with minimum overhead.

Encapsulation Protocols

You can select from two packet encapsulation formats for data transported across the ADSL WAN link: Point-to-Point Protocol (PPP) or High-level Data Link Control (HDLC), which is the default. HDLC is the preferred when the system is terminated at each end with PairGain products that have Ethernet ports. PPP is used when interfacing to a WAN port on non-PairGain equipment. In PPP mode, the Megabit Modem CRA-C supports the Bridge Control Protocol (BCP) RFC 1638 when configured as a bridge and the Internet Protocol Control Protocol (IPCP) RFC 1332 when configured as a router.

66 Megabit Modem CRA-C User Manual

TECHNICAL SPECIFICATIONS

ADSL Line

Signal Format CAP Line Code Transmit Signal Power up to 23 dBm Connector RJ-48

Ethernet Port

Connector RJ-45, 10BASE-T Bandwidth Filtering 14 Kpps (64-byte packets, both

directions) Forwarding Performance 2.7 Kpps Address Learning 2000 MAC addresses with aging Encapsulation Format Low-overhead HDLC or PPP Bridging IEEE 802.1d transparent with

Spanning Tree Protocol Routing Static IP maps

Physical

Height 2.2 inches (5.6 cm) Width 7.5 inches (19.0 cm) Depth 9.5 inches (24.13 cm)

Electrical

Power Input 100 to 130 VAC, 60 Hz Power Dissipation 8 W

Environmental

Temperature 0 to 50°C Relative Humidity 0 to 85% Electromagnetic Emissions Per FCC Part 15 Class A

Megabit Modem CRA-C User Manual 67

Technical Specifications

Management and Maintenance

Embedded SNMP Agent BOOTP/TFTP download (with RFC 1542 extensions) RFC 1533 Dynamic Host Configuration Protocol RFC 1213 MIB II, RFC 1493 bridge MIB (base, ST, transparent groups) PairGain xDSL bridge MIB extensions RFC 1215 Traps (link state) and ST Traps (newRoot, topology Changed)

ASCII Terminal Maintenance Port

Type RS-232C, RJ-45 Data Rate Autobaud from 2400 to 19,200 baud Hardware Flow Control Not Supported

Agency Certifications

FCC B UL CE CSA

PairGain reserves the right to change features and specifications without notice.

68 Megabit Modem CRA-C User Manual

TECHNICAL ASSISTANCE

PairGain Technical Assistance is available 24-hours-a-day, 7-days-a-week by contacting PairGain’s Customer Service Engineering group at one of the following numbers:

Telephone: (800) 638-0031

(714) 832-9922

Fax: (714) 832-9924

During normal business hours (8:00 AM to 5:00 PM, Pacific Time, Monday Friday, excluding holidays), technical assistance calls are normally answered directly by a Customer Service Engineer. At other times, a request for technical assistance is handled by an on-duty Customer Service Engineer through a callback process. This process results in a callback normally within 30 minutes of initiating the request.

World-Wide Web

PairGain product, company, and application information can be found at http://www.pairgain.com using any Web browser.

FTP

PairGain Management Information Bases (MIBs) are available using the Internet at ftp.pairgain.com, use:

FTP ftp.pargain.com

•



use guest or your e-mail address as you user password



enter cd snmp/rex/mibs get pgrexmib.txt

•

Megabit Modem CRA-C User Manual 69

Technical Assistance

70 Megabit Modem CRA-C User Manual

LIMITED WARRANTY

PairGain Technologies, Incorporated warrants its products to be free of defective and faulty workmanship for a period of 60 months, under normal use, from the date of shipment. PairGain's obligation, under this warranty, is limited to replacing or repairing, at PairGain's option, any such product which is returned during the warranty period per PairGain's instructions and which product, in PairGain's sole option, is determined to be defective upon examination at our plant.

Do not disassemble the Megabit Modem CRA-C. The unit’s components are not user serviceable. Opening the system chassis, or attempting to modify the unit in any way voids its warranty.

The transportation charges from the Buyer to PairGain will be prepaid by the Buyer. When the equipment is shipped back to the Buyer, PairGain will pay the charges, unless no trouble is found (NTF), in which case the buyer will pay for the shipment.

PairGain may use reconditioned parts for such repair or replacement. This warranty

does not

or altered by persons not authorized by PairGain or in PairGain's sole judgment has subjected to misuse, accident, fire or other casualty, or operation beyond its design range.

apply to any product which has been repaired, worked upon,

Repaired products have a 90-day warranty, or until the end of the original warranty period--whichever period is greater.

Modules sent to PairGain for repair will be repaired or replaced and returned to you as soon as possible. Normally, current products are repaired within 14 calendar days, and out-of-production products are repaired within 30 calendar days.

To return equipment to PairGain:

Call PairGain Customer Service at (800) 370-9670, or send a

fx to (714) 730-2961, to get a

(RMA) Number

and instructions for returning your

Return Material Authorization

equipment. For other information or questions, PairGain Technologies

can be contacted by telephone at (800) 638-0031 or (714) 832-9922 or by fax at (714) 832-9924.

Megabit Modem CRA-C User Manual 71

Limited Warranty

Provide the following information along with the equipment you're returning:

Your company name, address, and the name of the person

•

whom we can contact in case we have any questions. The same Purchase Order Number you gave us when you

•

requested your RMA number. A description of the equipment, as well as the number of

•

units you're returning to us. model and part number of each unit.

Shipping address so that we can return your equipment to

•

you.

So we can determine why you're sending the equipment to us, let us know which of the following applies to you:

The equipment needs an ECO/ECN upgrade.

•

The equipment is defective.

•

Please tell us what you observed just before the equipment malfunctioned. Be as detailed in your description as possible.

Don't forget

to include the

If there's another reason for returning the equipment, please let

•

us know what it is so we can help you.

Pack the equipment in a shipping carton.

Write clearly on the outside of the carton, PairGain’s address and

the assigned PairGain Technologies, Inc.

14352 Franklin Avenue Tustin, CA 92780-7013 Attention:

72 Megabit Modem CRA-C User Manual

Return Material Authorization Number

Repair and Return Department

GLOSSARY

The Glossary defines technical terms and abbreviations used in this manual.

Access Provider See Service Provider. Access Rate The transmission speed, in bits per second, of the

physical access circuit between the end user and the network.

ADSL Asymmetric Digital Subscriber Line. A method

of transmitting at different downstream and upstream speeds.

Alarm Any valid change of state from its normal condition

detected at an alarm point.

Asymmetric Transmission Transmission which sends data at different rates in

each direction.

AWG American Wire Gauge. ATU-C ADSL Terminal Unit at the service provider site. ATU-R ADSL Terminal Unit at the remote site. Bandwidth Used to describe the capacity or amount of traffic

(data, voice, or video) a certain communications line is capable of accommodating.

BER Bit Error Rate. The ratio of received bits that are

in error.

Binder Group A group of 25 or 50 pairs of wires. Bit In a binary system, the smallest unit of information.

It is represented as a zero or a one.

Bridge A two-port internetworking device that selectively

filters or forwards traffic based or MAC addresses.

Bridged A pair of wires connected in parallel across a single

line to form a "T" Tap configuration.

Megabit Modem CRA-C User Manual 73

Glossary

CAP Carrierless Amplitude Phase Modulation. A two-

dimensional line code used in ADSL.

Crosstalk Line noise that occurs due to coupling of signals

between pairs in the same bundle.

Downstream The direction of data reception from the Megabit

Modem CRA-C to a remote unit.

Ethernet A baseband LAN specification that has become a

series of standards produced by IEEE referred to as IEEE 802.3.

HDLC High-level Data Link Control. Hub A common wiring point for star-topology networks,

and a common synonym for a concentrator.

IEEE Institute of Electrical and Electronics Engineers.

A professional organization that defines network standards.

I/F Interface or Interface Card. ISP Internet service provider. kbps Kilobits per second. A measure of transmission

speed at 1,000 bits per second.

kpps Kilo packets per second. LAN Local Area Network. The means by which a local

community of users and workgroups can share information and resources electronically.

LED Light emitting diode. Line code Any method of converting digital information to

analog form for transmission on a communicaton line.

Link Another term used for transmission line. MAC Media Access Control. Associated with Layer 2

or the Data Link Layer of the ISO 7-layer protocol model.

Margin An ADSL parameter, measured in dB. It indicates

the excess SNR, relative to the performance of 10

–7

BER, at the receiver point.

74 Megabit Modem CRA-C User Manual

Glossary

Mbps Megabits per second. 1,000,000 bits per second. MDI Media Dependent Interface. MDI-X Media Dependent Interface (cross-over). MIB Management Information Base. NVRAM Non-Volatile Random Access Memory. Port An I/O interface. A point at which signals may be

introduced or extracted in a similar manner.

POTS Plain Old Telephone Service. PPP Point-to-Point Protocol. RAM Random Access Memory. Repeater Connects to line segments to amplify and reshape

the analog waveform to extend network segment distances.

RFC Request for Comment. Router Device that decides whether to forward a packet

by looking at the protocol level address.

Service Provider Organization providing and maintaining network

services for subscribers.

SNMP Simple Network Management Protocol. A network

management standard initially established to allow multi-vendor networking devices to be managed more easily with common management tools.

SNR Signal-to-Noise ratio. Spanning Tree An algorithm used to open bridging loops. Telecommuter A person who performs work at home while linked

to the office by means of a telecommunicationsequipped computer system.

Upstream The direction of data transmission from the Megabit

Modem CRA-C to a remote unit.

UTP Unshielded Twisted Pair.

Megabit Modem CRA-C User Manual 75

Glossary

76 Megabit Modem CRA-C User Manual

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ADC CRA-C User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

ABOUT THE MEGABIT MODEM CRA-C

About Rate Adaptive Transmission

Rate Adaptation

Reach, Data Rate, SNR Margin, and Noise Environment

INSTALL THE MEGABIT MODEM CRA-C

Unpack and Inspect the Shipment

Identify LEDs and Connectors

Front Panel

Rear Panel

Install the Megabit Modem CRA-C

connect to the ADSL line

Connect to the Data Network

Power Up and Check LEDs

CONFIGURE AND VIEW STATUS

Connect to an ASCII Terminal

How to Log On and Navigate the Menus

How to Configure a Remote Unit

Configure the System Settings

Configure the ADSL Transceiver

Configuration

Reset the ADSL Transceiver

Configure the Bridge/Router

Configure as a Bridge

Configure as a Router

Configure SNMP

Reset the Ethernet Bridge

View Status

System Information

ADSL Transceiver Status

Ethernet Bridge Statistics

Log Out

NETWORK AND MANAGEMENT OVERVIEW

MAC Layer Bridging and Spanning Tree Protocol

Static IP Routing

Megabit Modem CRA-C IP Addresses

Management Protocols

SNMP

Megabit Modem CRA-C SNMP Agent

MIB and Trap Support

Network Configuration and Image Code Download

BOOTP

TFTP

Encapsulation Protocols

TECHNICAL SPECIFICATIONS

TECHNICAL ASSISTANCE

World-Wide Web

LIMITED WARRANTY

GLOSSARY