RAD Data comm ASMI-450 User Manual

ASMi-450

High-Speed HDSL Modem

Installation and Operation Manual

Notice

This manual contains information that is proprietary to RAD Data Communications. No part of this
publication may be reproduced in any form whatsoever without prior written approval by RAD Data
Communications.

No representation or warranties for fitness for any purpose other th an wh at is specifically mentioned in this
manual is made either by RAD Data Communications or its agents.

For further information contact RAD Data Communications at the address below or contact your local
distributor.

RAD data communications
Headquarters

12 Hanechoshet Street
Tel Aviv 69710 Israel
Tel: [phone]
Fax: [phone]
E-mail: [e-mail]

© 1997 RAD Data Communications Ltd. Publication No. 634-200-11/97

RAD data communications
US East

900 Corporate Drive
Mahwah, NJ 07430 USA
Tel: [phone]
Fax: [phone]
E-mail: [e-mail]

RAD data communications
US West

7711 Center Avenue #350
Huntington Beach, CA 92647 USA
Tel: [phone]
Fax: [phone]

Warranty

This RAD product is warranted against defects in material and workmanship for a period of one year from
date of shipment. During the warranty period, RAD will, at its option, either repair or replace products
which prove to be defective. For warranty service or repair, this product must be returned to a service
facility designated by RAD. Buyer shall prepay shipping charges to RAD and RAD shall pay shipping
charges to return the product to Buyer. However, Buyer shall pay all shipping charges, duties and taxes for
products returned to RAD from another country.

Limitation of Warranty

The foregoing warranty shall not apply to defects resulting from improper or inadequate maintenance by
Buyer, Buyer-supplied firmware or interfacing, unauthorized modification or misuse, operation outside of
the environmental specifications for the product, or improper site preparation or maintenance.

Exclusive Remedies

The remedies provided herein are the Buyer’s sole and exclusive remedies. RAD shall not be liable for any
direct, indirect special, incidental, or consequential damages, whether based on contract, tort, or any legal
theory.

Safety Warnings

The exclamation point within a triangle is intended to warn the operator or service
personnel of operation and maintenance factors relating to the product and its operating
environment which could pose a safety hazard.

Always observe standard safety precautions during installation, operation and maintenance of this product.
Only qualified and authorized service personnel should carry out adjustment, maintenance or repairs to this
instrument. No adjustment, maintenance or repairs should be performed by either the operator or the user.

Telecommunication Safety

The safety status of each of the ports on the ASMi-450 is declared according to EN 41003 and is detailed
in the table below:

Safety Status Ports

SELV RS-530, X.21, V.35, V.24, V.36
TNV operating within the limits of SELV HDSL

SELV = Safety Extra-Low Voltage
TNV = Telecommunications Network Voltage

Regulatory Information

FCC-15 User Information

This equipment has been tested and found to comply with the limits of the Class A 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 the instruction
manual, may cause harmful interference to the radio communications. Operation of this equipment in a
residential area is likely to cause harmful interference in which case the user will be required to correct the
interference at his own expense.

Warning per EN 55022

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

Declaration of Conformity

Manufacturer’s Name:

Manufacturer’s Address:

declares that the product:

Product Name: ASMi-450

Conforms to the following standard(s) or other normative document(s):

EMC:

Safety:

Supplementary Information:

The product herewith complies with the requirements of the EMC Directive 89/336/EEC and the
Low Voltage Directive 73/23/EEC. The product was tested in a typical configuration.

EN 55022 (1994) Limits and methods of measurement of radio disturbance

EN 50082-1 (1992) Electromagnetic compatibility - Generic immunity

EN 60950 (1992/93) Safety of information technology equipment, including

RAD Data Communications Ltd.
12 Hanechoshet St.

Tel Aviv 69710
Israel

characteristics of information technology equipment.

standards for residential, commercial and light industry.

electrical business equipment.

Tel Aviv, January 23rd, 1997

European Contact:

RAD Data Communications GmbH, Lyoner Strasse 14, 60528 Frankfurt am Main, Germany

Haim Karshen
VP Quality

Chapter 1 Introduction

1.1 Functional Description....................................................................................................................... 1-1

Purpose and Main Features............................................................................................................... 1-1

Serial Data Port Characteristics ........................................................................................................1-2

Ethernet Interface Characteristics.....................................................................................................1-2

HDSL Subsystem Characteristics.....................................................................................................1-3

System Timing..................................................................................................................................1-4

Control of ASMi-450 Operation....................................................................................................... 1-5

1.2 Operating Environment...................................................................................................................... 1-8

Transmission Media..........................................................................................................................1-8

HDSL Line Signal ............................................................................................................................1-8

HDSL Signal Structure..................................................................................................................... 1-9

HDSL-Related System Functions.....................................................................................................1-9

1.3 Technical Specifications ..................................................................................................................1-10

Chapter 2 Installation

2.1 General...............................................................................................................................................2-1

2.2 Unpacking.......................................................................................................................................... 2-2

2.3 Site Requirements .............................................................................................................................. 2-2

Power................................................................................................................................................2-2

User's Port Connections.................................................................................................................... 2-2

HDSL Line Connections................................................................................................................... 2-2

Front and Rear Panel Clearance........................................................................................................2-2

Ambient Requirements .....................................................................................................................2-2

2.4 ASMi-450 Configuration Information............................................................................................... 2-3

General.............................................................................................................................................. 2-3

Opening ASMi-450 Case.................................................................................................................. 2-3

Jumper and Switch Location and Functions.....................................................................................2-4

Internal Settings Procedure...............................................................................................................2-7

Reinstalling ASMi-450 Cover ..........................................................................................................2-7

2.5 Connections................................................................................................................ ........................ 2-8

Connector Location........................................................................................................................... 2-8

Grounding......................................................................................................................................... 2-8

Power Connection............................................................................................................................. 2-9

User's Port Connections.................................................................................................................... 2-9

HDSL Line Connections................................................................................................................. 2-10

Control Port Connection................................................................................................................. 2-10

Contents

Chapter 3 Front-Panel Operating Instructions

3.1 Scope.................................................................................................................................................. 3-1

3.2 Front Panel Controls, Connectors, and Indicators ............................................................................. 3-2

Ethernet Interface Indicators............................................................................................................. 3-3

3.3 Control of ASMi-450 Operation, General ......................................................................................... 3-4

General.............................................................................................................................................. 3-4

General Operating Instructions.........................................................................................................3-4

Display Functions .............................................................................................................................3-4

ASMi-450 Installation and Operation Manual vii

Contents

Organization of ASMi-450 Display.................................................................................................. 3-6

Using Front-Panel Push-buttons....................................................................................................... 3-6

3.4 System Configuration Parameters......................................................................................................3-8

3.5 Control Port Configuration Parameters..............................................................................................3-9

3.6 Operating Instructions...................................................................................................................... 3-10

Turn-on........................................................................................................................................... 3-10

Checking Current Operating Configuration....................................................................................3-10

Normal Indications.......................................................................................................................... 3-11

Fault Indications ............................................................................................................................. 3-12

Turn-off...........................................................................................................................................3-12

3.7 Local Configuration Set-Up Procedure............................................................................................3-13

Password Protection........................................................................................................................3-13

General Configuration Procedure...................................................................................................3-13

Specific Configuration Guidelines..................................................................................................3-15

3.8 LCD Configuration Error Messages ................................................................................................3-17

Chapter 4 ASMi-450 Control from the Control Port........................................................................................... 4-1

4.1 General...............................................................................................................................................4-1

4.2 Hardware Requirements.....................................................................................................................4-2

Terminal Characteristics................................................................................................................... 4-2

Communication Requirements.......................................................................................................... 4-2

Handshaking Protocol ....................................................................................................................... 4-2

AUTOBAUD Function..................................................................................................................... 4-4

4.3 Preparation for Use of Supervision Terminal ....................................................................................4-5

ASMi-450 Preparations .................................................................................................................... 4-5

Supervision Terminal........................................................................................................................4-5

Connections ...................................................................................................................................... 4-5

4.4 ASMi-450 Supervision Language......................................................................................................4-6

Command Language Syntax.............................................................................................................4-6

Command Options............................................................................................................................ 4-6

Command Protocol ...........................................................................................................................4-6

Index of Commands.......................................................................................................................... 4-7

4.5 ASMi-450 Command Set Description ............................................................................................... 4-9

4.6 Control Terminal Operating Instructions.........................................................................................4-26

Starting a Session - Single ASMi-450 ............................................................................................4-26

Starting a Session - Multiple ASMi-450......................................................................................... 4-27

Control Session............................................................................................................................... 4-27

Ending a Control Session................................................................................................................4-28

4.7 Configuration Error Messages.........................................................................................................4-29

Chapter 5 Diagnostics

5.1 General...............................................................................................................................................5-1

5.2 Status Indications and Messages........................................................................................................ 5-1

Indicators .......................................................................................................................................... 5-1

Display..............................................................................................................................................5-1

5.3 Test Functions....................................................................................................................................5-6

Test Functions................................................................................................................................... 5-6

TEST OPTIONS Operating Instructions .......................................................................................... 5-7

viii ASMi-450

Installation and Operation Manual

Activating the Test Functions from a Control Terminal................................................................... 5-8

5.4 Power-Up Self-Test ...........................................................................................................................5-8

5.5 Troubleshooting Instructions ............................................................................................................. 5-9

Appendix A Connector Wiring

A.1 RS-530 DCE Connector and Adapter Cables .................................................................................. A-1

A.2 V.35 DCE Connector....................................................................................................................... A-3

A.3 X.21 DCE Connector....................................................................................................................... A-4

A.4 HDSL Line Connector ..................................................................................................................... A-5

A.5 RS-232 (V.24) Control Port Connector ........................................................................................... A-5

A.6 Ethernet Interface Connector ........................................................................................................... A-6

Appendix B SNMP Management

B.1 Scope................................................................................................................................................ B-1

B.2 SNMP Environment......................................................................................................................... B-2

General............................................................................................................................................. B-2

SNMP Principles.............................................................................................................................. B-2

SNMP Operations.................................................................................................................................. B-2

The Management Information Base....................................................................................................... B-3

MIB Structure........................................................................................................................................ B-3

MIBs Supported by the ASMi-450 SNMP Agent ................................................................................. B-3

Management Domains Under SNMP .............................................................................................. B-4

SNMP Communities.............................................................................................................................. B-4

Access Restriction Using SNMP Communities..................................................................................... B-4

ASMi-450 Communities........................................................................................................................ B-5

Contents

B.3 IP Environment................................................................................................................................. B-6

General............................................................................................................................................. B-6

IP Environment................................................................................................................................ B-6

IP Address Structure.............................................................................................................................. B-6

B.4 SNMP Traps..................................................................................................................................... B-8

Appendix C Installation in 19" Racks

C.1 General............................................................................................................................................. C-1

C.2 Installation of Single Unit ................................................................................................................ C-2

C.3 Installation of Two Units.................................................................................................................. C-3

General............................................................................................................................................. C-3

Preparations ..................................................................................................................................... C-3

Fastening the Two Units.................................................................................................................. C-4

ASMi-450

Installation and Operation Manual

ix

Contents

x ASMi-450

Installation and Operation Manual

List of Figures

Figure 1-A. Typical Application for ASMi-450 with Data Interface ........................................................................1-2

Figure 1-B. Typical Application for ASMi-450 with Ethernet Interface................................................................... 1-2

Figure 1-C. Flow of Timing Signals through ASMi-450 System in the External Timing Mode...............................1-4

Figure 1-D. Flow of Timing Signals through ASMi-450 System in the Internal Timing Mode ...............................1-5

Figure 1-E. 2B1Q Encoding Rule.............................................................................................................................. 1-8

Figure 2-1. Identification of Cover Screws................................................................................................................ 2-4

Figure 2-2. ASMi-450 Internal Settings .................................................................................................................... 2-5

Figure 2-3. Typical ASMi-450 Rear Panels............................................................................................................... 2-8

Figure 3-A. ASMi-450 Front Panel...........................................................................................................................3-2

Figure 3-B. ASMi-450 Rear Panel (Ethernet Interface) ............................................................................................ 3-3

Figure 5-A. LOOP LOCAL PORT Loopback...........................................................................................................5-6

Figure 5-B. LOOP REM REM PORT Loopback...................................................................................................... 5-7

Figure C-1. Installation of Single Unit in 19" Rack.................................................................................................. C-2

Figure C-2. Preparation of Two ASMi-450 Units for Installation in 19" Rack........................................................ C-3

Figure C-3. Attachment of Two ASMi-450 Units Before Installation in 19" Rack.................................................. C-4

ASMi-450 Installation and Operation Manual xi

List of Figures

xii ASMi-450

Installation and Operation Manual

List of Tables

Table 3-A. ASMi-450 Controls, Connectors and Indicators ..................................................................................... 3-2

Table 3-B. Ethernet Interface Indicators....................................................................................................................3-3

Table 3-C. System Parameters...................................................................................................................................3-8

Table 3-D. Control Port Parameters........................................................................................................................... 3-9

Table 4-A. ASMi-450 Command Set Index ..............................................................................................................4-8

Table 4-B. Control Terminal Alarm Messages........................................................................................................ 4-17

Table 4-2. Control Terminal Alarm Messages (Cont’d).......................................................................................... 4-18

Table 4-2. Control Terminal Alarm Messages (Cont’d).......................................................................................... 4-19

Table 4-C. ASMi-450 Default Configuration Used with Control Terminal............................................................ 4-23

Table 5-A. ASMi-450 Alarm Buffer Messages.........................................................................................................5-2

Table 5-1. ASMi-450 Alarm Buffer Messages (Cont’d)........................................................................................... 5-3

Table 5-1. ASMi-450 Alarm Buffer Messages (Cont’d)........................................................................................... 5-4

Table 5-1. ASMi-450 Alarm Buffer Messages (Cont’d)........................................................................................... 5-5

Table 5-B. Troubleshooting Chart............................................................................................................................. 5-9

Table 5-2. Troubleshooting Chart (Cont’d)............................................................................................................. 5-10

Table A-1. RS-530 DCE Connector ......................................................................................................................... A-1

Table A-2. V.36/RS-449/422 DCE Interface Adapter Cable.................................................................................... A-2

Table A-3. V.35 DCE Connector.............................................................................................................................. A-3

Table A-4. DCE Connector, X.21 Interface ....................................................................................... ...................... A-4

Table A-5. LINE Connector, Pin Allocation ............................................................................................................ A-5

Table A-6. Control Port Interface Signals ................................................................................................................ A-5

Table A-7. Ethernet Interface Connector.................................................................................................................. A-6

ASMi-450 Installation and Operation Manual xiii

List of Tables

xiv ASMi-450

Installation and Operation Manual

Quick-Start Guide

If you are familiar with HDSL transmission equipment, use this guide to prepare
(configure) an ASMi-450 for operation. The configuration activities can be
carried out either before or after the ASMi-450 is installed in its intended
location.

1. Starting the Configuration

Preliminary
Preparations

Starting Procedure

To configure the ASMi-450, you need an ASCII terminal, e.g., a VT-100, etc.,
or a PC running a terminal emulation program. You also need a standard cable
terminated in a 9-pin D-type male connector, for connecting the serial port of
your terminal to the CONTROL DCE connector located on the front panel of the
ASMi-450.

Configure your terminal for eight data bits, no parity, one stop bit, echo off, and
no flow control. You can use 300, 1200, 2400, 4800, or 9600 bps - the
ASMi-450 will automatically recognize the data rate you are using.

1. Turn the ASMi-450 on.

2. Connect the terminal cable to the CONTROL DCE connector of the
ASMi-450.

3. Press the Carriage Return (<CR> or ENTER) key three times in sequence:
you should see the ASMi-450 prompt, ASMI>

If you see PASSWORD>, type ASMI and then press <CR> to obtain the prompt.
If you do not see the prompt:

• Check the terminal configuration, and its connections to the ASMi-450, and

then repeat step 3 above.

• Turn the ASMi-450 off about 15 seconds, and then turn it on again and

repeat step 3 above.

.

• If this is the first time you are working on this ASMi-450 unit, refer to

Section 4-3 for preliminary configuration instructions.

• Read ASMi-450 display. If the second row shows EMPTY, everything is

OK. If it shows SCROLL, press SCROLL and read the alarm messages.
Refer to Chapter 5 for instructions.

ASMi-450 Installation and Operation Manual Quick-Start Guide - 1

Quick-Start Guide

2. Configuration Procedure

You are ready to start ASMi-450 configuration. After typing a command, press
<CR> to see the data entry form:

• Use the space bar to move the cursor to the desired field.

• Use the F key to scroll forward, and the B key to scroll backward among the

available values. For free text fields, type the desired text.

• When ready, press <CR> to display the next data entry page of the current

command. Pressing<CR> after the last data entry, executes the command.

• You can exit without executing the changes by pressing CTRL-C at any

time before pressing <CR>.

To obtain correct display of data forms on your terminal, you must select the
terminal control sequences:

1. Type the command F.

2. In each field, type the code corresponding to your terminal type. The chart
below lists the codes for common terminal types:

Terminal Type

Function

TV920 VT52 VT100 Freedom 100/110 Freedom 220

Clear Screen 1B2A0000 N/A 1B5B324A 1B2A0000 1B5B324A

Cursor Home 1E000000 1B480000 1B5B4800 1E000000 1B5B4800

Cursor Right 0C000000 1B430000 1B5B3143 0C000000 1B5B0143

3. When done, press <CR>.

Configure the ASMi-450 in the following order:

Step Action Use the Command

1 Set ASMi-450 system time
2 Set ASMi-450 system date
3 Define control port characteristics
4 Define system characteristics
5 Define general system parameters

TIME
DATE
DEF SP
DEF SYS
DEF AGENT
DEF NAME
DEF NODE
DEF PWD

Quick-Start Guide - 2 ASMi-450 Installation and Operation Manual

Quick-Start Guide

3. Command Index

Display the index of commands by typing the help command, H. The following
table lists the available commands.

Type Configuration

System

HDSL Lines

User's Port

Supervisory Port

Tests

Display Commands Control Commands

Commands

DEF SYS DSP ST SYS RESET
DEF AGENT
DEF NAME DSP ALM INIT DB
DEF PWD DSP ALM REM CLR ALM
DEF NODE DSP HDR TST CLR REM ALM
DATE
TIME

DSP ST LINE
DSP HDSL PM LP1
or LP2
DSP R HDSL PM
LP1 or LP2

DSP ST PORT
DSP TS

DEF SP DSP ST SP H
INIT F EXIT
F

LOOP L PORT
LOOP R R PORT
CLR TST
CLR LOOP L PORT
CLR LOOP R PORT

ASMi-450 Installation and Operation Manual Quick-Start Guide - 3

Quick-Start Guide

Notes

Quick-Start Guide - 4 ASMi-450 Installation and Operation Manual

Chapter 1
Introduction

1.1 Functional Description

Purpose and Main
Features

The ASMi-450 is a high-speed HDSL modem that enables long-range data
transmission over one unconditioned twisted-pair line, using the High Bit Rate
Digital Subscriber Line (HDSL) technology.

The HDSL technology offers a cost-effective and reliable solution for delivering
high-speed data to the subscriber premises over the existing copper cables and
subscriber loops of the local distribution plant.

The ASMi-450 is fully compatible with the ASMi-450C high-speed HDSL
modem card, which is intended for installation in the 12-Card HDSL/Modem
Hub with SNMP Management, LRS-12, offered by RAD.

The ASMi-450 can transmit full duplex over unconditioned AWG-22,
AWG-24, and AWG-26 twisted pair loops. Using advanced equalization,
adaptive filtering, and echo cancellation techniques, the ASMi-450 compensates
for line impairments, bridged taps, and mixed cables commonly encountered in
the local distribution network. Moreover, due to its high immunity to
background noise, the ASMi-450 enables the transmission of multiple HDSL
signals in the same physical cable without requiring pair selection.

The ASMi-450 is available in two versions, optimized for maximum range in
accordance with the user's payload data rate:

• ASMi-450/1152: can transmit data rates of n×64 kbps, where n is 1 through

18 (corresponding to data rates of 64 to 1152 kbps). Typical ranges are up
to 4.5 km over AWG-24 (0.5 mm) cable, and up to 3.6 km over AWG-26
(0.4 mm) cable.

• ASMi-450/768: can transmit data rates of n×64 kbps, where n is 1 through

12 (corresponding to data rates of 64 to 768 kbps). Typical ranges are up to

5.7 km over AWG-24 (0.5 mm) cable, and up to 4.1 km over AWG-26
(0.4 mm) cable.

Both ASMi-450 versions are available with two types of user interfaces:

• Serial data port. The port can be ordered with V.35, RS-530, or X.21

interface (the RS-530 interface also supports V.36/RS-422/RS-442 by
means of an adapter cable).

ASMi-450 Installation and Operation Manual 1-1

Introduction

• Ethernet 10BaseT interface. The interface can use unshielded and shielded

twisted pair (UTP and STP) media. The ASMi-450 also includes a remote
bridge, that can be enabled/disabled by the user.

Figure 1-1 shows a typical application for an ASMi-450 with serial data
interface, and figure 1-2 shows a typical application for an ASMi-450 with
Ethernet interface.

LAN

BRIDGE

LOCAL

LAN

Serial Data Port
Characteristics

V.35

768kbps

ASMI-450

HDSL Line

V.35

768kbps

ASMI-450

Figure 1-A. Typical Application for ASMi-450 with Data Interface

HDSL Line

ASMI-450

ASMI-450

Figure 1-B. Typical Application for ASMi-450 with Ethernet Interface

The user's data port of the ASMi-450/768 and ASMi-450/1152 can be ordered
with the following interface options:

• V.35 interface: 34-pin female connector.

• X.21 interface: 15-pin D-type female connector.

• RS-530/RS-422 interface: 25-pin D-type female connector.

LAN

BRIDGE

REMOTE

LAN

• V.36/RS-422/RS-449 interface: a 37-pin D-type male connector is provided

by means of an adapter cable that connects to the RS-530/RS-422
connector.

The user's port interface has two timing options:

• Internal clock - the ASMi-450 user's port provides transmit and receive

clock to the equipment connected to the port.

• External clock - the equipment connected to the ASMi-450 provides the

transmit clock to the user's port, and the ASMi-450 returns a receive clock
locked to the external transmit clock.

Ethernet Interface
Characteristics

The Ethernet interface has a 10BaseT interface complying with the IEEE 802.3
standard, and is terminated in an RJ-45 shielded connector, which can operate
over UTP and STP media.

1-2 ASMi-450 Installation and Operation Manual

Introduction

The interface includes a full-feature remote bridge, that operates at the physical
and data link layers of the OSI model, and is therefore completely transparent to
higher level protocols, such as TCP/IP, DECnet, XNS, ISO, and to operating
systems, such as NetWare, VINES, and 3COM+.

The bridge operates as a media access (MAC) layer remote bridge with self­learning capabilities: it learns and automatically recognizes the addresses of the
nodes attached to the local LAN (the LAN directly attached to the ASMi-450
interface), and uses this information to filter the LAN traffic. The address
information is stored in tables, which can store up to 10,000 addresses. The
address information is automatically updated (aging time is 5 minutes, that is, if
no frames are received from a node for 5 minutes, the node address is
automatically removed from the tables to ensure that only fresh addresses are
used).

Therefore, the bridge blocks the packets addressed to local nodes, and forwards
through the ASMi-450 link only multicasts, broadcasts, and packets addressed
to nodes attached to the remote LAN. To increase transmission efficiency, the
bridge compresses short packets by automatically recognizing the padding bits
in 64-bit frames, transmitting only the payload, and reconstructing the packets
at the remote end.

HDSL Subsystem
Characteristics

The filtering and forwarding can be performed at a rate of up to 15,000 packets
per second (provided the bandwidth selected on the HDSL link is sufficient to
carry the resulting payload rate).

When bridging is not necessary, e.g., for LAN extender applications, the user
can disable the bridge: in this case, the ASMi-450 operates as a repeater that
transfers transparently all the traffic to the remote end.

The ASMi-450 HDSL subsystem uses duplex transmission over one 2-wire line.
The ASMi-450 can operate on unloaded AWG-22, AWG-24, and AWG-26
twisted-wire pairs, and other similar pairs. Up to two bridged taps, having a
length of up to 500 meters, are tolerated.

The HDSL line interface is terminated in an RJ-45 eight-pin connector.
The line code on the HDSL lines is 2B1Q at a symbol rate approximately equal

to half the maximum data rate:

• ASMi-450/768: 392 kbaud

• ASMi-450/1152: 584 kbaud.

The increased symbol rate is used to provide framing and synchronization, and
an embedded operations channel, which enables end-to-end system management
and supervision.

The HDSL subsystem operates in a master-slave mode:

• The central unit, located at the central office side of the link, which serves

as the line termination unit (LTU), controls the system start-up procedure,
and provides the timing reference for HDSL line transmission.

ASMi-450 Installation and Operation Manual 1-3

Introduction

• The remote unit, located at the remote end of the link (customer side),

serves as the network termination unit (NTU).

The ASMi-450 supports both the central (LTU) and the remote (NTU) operating
modes; the actual operating mode (LTU or NTU) is user-selectable.

System Timing

The ASMi-450 offers selectable timing options, which enable the distribution of
timing over the HDSL system, from the central office to the remote end.

• ASMi-450 Unit Configured as Central Unit (LTU). The ASMi-450 unit

configured as central unit has two timing modes: external timing and
internal timing.

àExternal timing. With external timing, the ASMi-450 system timing is

locked to the clock signal received from the user's equipment (this mode
is not supported when the ASMi-450 is equipped with an Ethernet
interface). This mode allows locking the system timing to the timing of
the network to which the local ASMi-450 unit is connected, and thus it
enables providing the network timing to the equipment on the
customer's premises.

The local HDSL transmit timing is locked to the incoming clock signal,
therefore the transmit path of the local ASMi-450 transparently transfers
the timing from the user's equipment to the HDSL line.

Figure 1-3 shows the flow of timing signals through the ASMi-450 system in
the external timing mode.

CENTRAL ASMi-450

REMOTE ASMi-450

HDSL Line

Local

User's

DTE

Timing
Source

User

Interface

HDSL Line

Interface

HDSL Line

Interface

User

Interface

Figure 1-C. Flow of Timing Signals through ASMi-450 System in the External Timing Mode

àInternal timing. With internal timing, the ASMi-450 system timing is

determined by the clock signal generated by an internal crystal
oscillator. This clock signal is supplied to the HDSL transmit path and
to the user's equipment.

The internal timing mode is suitable for point-to-point configurations.
Figure 1-4 shows the flow of timing signals through the ASMi-450

system in the internal timing mode.

Remote

User's

DTE

1-4 ASMi-450 Installation and Operation Manual

Introduction

g

g

Local

User's

DTE

Timin
Source

Figure 1-D. Flow of Timing Signals through ASMi-450 System in the Internal Timing Mode

Control of
ASMi-450
Operation

CENTRAL ASMi-450

Internal

~

Timin

User

Interface

HDSL Line

Interface

HDSL

Line

REMOTE ASMi-450

HDSL Line

Interface

User

Interface

Remote

User's

• ASMi-450 Unit Configured as Remote Unit (NTU). The ASMi-450 unit

configured as remote unit always locks its internal system timing to the
incoming HDSL signal, which is received from the ASMi-450 unit
configured as central unit. The receive path of the ASMi-450 uses the
recovered timing to generate the data stream supplied to the equipment
connected to the remote user's port. Therefore, the receive path of the
remote ASMi-450 transparently transfers the timing from the HDSL line to
the remote user's equipment.

The ASMi-450 system is designed for unattended operation. The configuration
of the ASMi-450, that is, a complete collection of operating parameters, is
determined by a data base stored in non-volatile memory.

DTE

Local Control

The ASMi-450 can be controlled by means of a simple menu, operated by push­buttons located on the front panel. During set-up, an LCD display guides the
operator in the execution of the desired operations. The display provides
information concerning the current system configuration and operating mode,
and the available values of each programmable parameter. In case of operator
errors, the ASMi-450 displays a message that explains the error and helps the
operator take the correct action.

Remote Management

In addition to front panel control, the ASMi-450 supports management from a
remote location. The remote management capabilities can be used to perform
the following activities:

• ASMi-450 configuration.

• Reading of ASMi-450 status.

• ASMi-450 testing.

• Display of alarm status and history.

ASMi-450 Installation and Operation Manual 1-5

Introduction

The remote management functions are performed through a serial RS-232 port
that enables serial communication with a supervision terminal.

Using the supervision terminal functions, the user can also enable remote
management using IP communications, i.e., Telnet and SNMP. The IP
communication uses the Serial Link Internet Protocol (SLIP).

Note

Support for Telnet and SNMP is available for ASMi-450 with software version

1.0 and higher. If your ASMi-450 does not support Telnet and SNMP, contact

RAD Technical Support Department for upgrade information.

The remote management capabilities available through the serial RS-232 port
are as follows:

• Management by means of a Supervision Terminal. Any “dumb” ASCII

terminal connected to the RS-232 port of the ASMi-450 (or a PC running a
terminal emulation program), controlled by the program stored in the
ASMi-450, can be used as a supervision terminal. The control port can be
used to perform the following activities:

àASMi-450 configuration.
àReading of ASMi-450 status.
àASMi-450 testing.
àDisplay of alarm status and history.

The supervision terminal can communicate with the ASMi-450 using
either point-to-point, or polled (multidrop) communication. For polling
purposes, each ASMi-450 can be assigned an eight-bit address, for a
maximum of 255 nodes (the zero address is reserved for non-polled
communication).

As an option, a dial-up modem can be connected to the control port, to
provide call-in capabilities.

In addition to the remote management functions listed above, the
supervision terminal is also used for the preliminary configuration of
the ASMi-450, to enable the use of IP communication for Telnet and
SNMP management.

• Management by means of Telnet. The ASMi-450 also supports the Telnet

protocol, which enable remote management using the same command line
interface available with a supervision terminal. Telnet uses TCP/IP
communication through the RS-232 port of the ASMi-450.

• SNMP Management. The SNMP management capability enables fully

graphical, user-friendly management using the RADview network
management stations offered by RAD, as well as management by other
SNMP-based management systems.

1-6 ASMi-450 Installation and Operation Manual

Introduction

Test and Diagnostics Capabilities

The ASMi-450 has comprehensive diagnostics capabilities. ASMi-450 models
with serial data port support the following types of test functions:

• Local loopback on the user's port of the local ASMi-450 (LOOP LOCAL

PORT).

• Remote loopback on the user's port of the remote ASMi-450 (LOOP REM

REM PORT).

These loopbacks may not be activated for an ASMi-450 equipped with Ethernet
interface, because this would cause a continuous state of collision on the LAN,
thereby disrupting the traffic on the LAN.

Maintenance is further enhanced by advanced self-test capabilities, and by an
automatically performed power-up self-test that provides circuit-level
diagnostics data.

Alarms

The ASMi-450 stores alarms detected during its operation in a buffer that can
hold up to 100 alarms. During regular operation, the front panel LCD display
shows if there are any alarms in the alarm buffer, to notify the local operator
that alarm conditions have been detected. The local operator can then review the
contents of the alarm buffer on the front panel display, and can delete old
alarms.

In addition to the alarm buffer, front-panel LED indicators display in real time
the activity on the ASMi-450 user's port, the state of the LAN, and the
synchronization status and transmission quality of the HDSL line, and alert
when test loops are present in the system.

Physical Characteristics

The ASMi-450 is a compact unit, intended for installation on desk tops or
shelves. Unit height is only 1U (1.75").

An optional rack-mount adapter kit enables the installation of one or two
ASMi-450 units in a 19" rack.

Power Requirements

The ASMi-450 can be powered by 115 VAC and 230 VAC, 47 to 63 Hz. As an
option, the ASMi-450 can also be ordered with a -48 VDC power supply.

ASMi-450 Installation and Operation Manual 1-7

Introduction

1.2 Operating Environment

This section describes the HDSL environment, with special emphasis on the
implementation used in the ASMi-450 to provide the background information
required for understanding the configuration parameters of the ASMi-450
system.

Transmission
Media

HDSL Line Signal

HDSL systems are intended to operate on the local subscriber plant, which
typically uses a mixture of unshielded twisted-wire pairs. Moreover, it also
necessary to tolerate bridges taps. Therefore, HDSL systems must operate
properly on this media. The only requirement is that the lines must not be
loaded. In addition, it is assumed that the nominal impedance of the loops is
135 ohms, and that the loops are balanced with respect to ground.

The line code on the HDSL loop is 2B1Q (2 Binary, 1 Quaternary). This is a
four-level pulse-amplitude modulation code without redundancy, under which
each pair of information bits is converted to a quaternary symbol, called quat
(bits can assume two signal levels, whereas quats have four levels).

The encoding rule of the 2B1Q code is as follows:

Binary Digits Quaternary Symbol

00 -3
01 -1
10 +3
11 +1

The levels of the quaternary signal are symmetrically located around the 0V,
and the nominal peak symbol level specified by the HDSL standards is 2.64V.
Figure 1-5 illustrates the 2B1Q encoding rule.

+3 (+2.64V)

+1 (+0.88V)

(0.00V)

-1 (-0.88V)

-3 (-2.64V)
Quats

Bits

-101+310+111-300-300+111+310-300-101-101+111-101-300+310+310-101+1

time

11

Figure 1-E. 2B1Q Encoding Rule

Due to the encoding of two bits into one symbol, the symbol rate on the HDSL
line is half the bit rate. Taking into consideration the highest payload rate
supported by the ASMi-450, 1152 kbps, and some overhead, the required line
data rate is 1168 kbps (equivalent to a symbol rate of 584 kbaud).

1-8 ASMi-450 Installation and Operation Manual

Introduction

By reducing the line symbol rate, the maximum range that can be reached is
increased. This is achieved by offering several versions of ASMi-450, each
operating up to a given maximum rate. Together with the advanced digital
signal processing techniques implemented in HDSL systems, this results in a
robust data transmission system that can reliably operate over regular
unconditioned local loops.

HDSL Signal
Structure

HDSL-Related
System Functions

The HDSL signal is organized in frames. The HDSL frames carry user data,
framing and synchronization data, and overhead data. The overhead data is used
for a supervision and management channel, called embedded operations channel
(EOC) that serves for status transfer, diagnostic loopbacks and tests, etc.

The HDSL subsystem performs the following main functions:

• Mapping of input data bits into frames.

• Start-up process.

• Frame alignment.

• System management by means of the EOC channel.

To achieve proper operation, one of the unit<F14P11>s serves as the master that
controls the system start-up procedure, provides the timing reference for HDSL
loop transmission, and manages the communication on the EOC channel. The
master unit is called line termination unit (LTU) and is located at the central
office side of the link; the other unit is called network termination unit (NTU)
and is located at the remote end of the link.

The transmission of data on the HDSL loop is full duplex. To enable duplex
transmission, HDSL transceivers use an echo canceller, based on advanced
digital signal processing (DSP) techniques. When starting system operation, the
echo canceller is “trained”, to enable the separation of the received signal from
the transmit signal. The training is performed by transmitting a special sequence
for a predetermined period. This process is called “start-up process”; data
transmission can start only after its successful completion.

ASMi-450 Installation and Operation Manual 1-9

Introduction

1.3 Technical Specifications

HDSL Interface

Signal Format 2B1Q line coding
Line Type One unconditioned, unloaded twisted pair
Nominal Impedance 135Ω
Transmit Pulse Shape Per ANSI T1E1.4/92-002RI and ETSI ETR-152
Transmit Signal Power +13 dBm

35 dB max. at 200 kHz (392 kbaud)

Loop Loss

Typical Range (AWG 24 Wire (0.5 mm))

392 kbaud 5.7 km
584 kbaud 4.5 km

−

31 dB max. at 150 kHz (584 kbaud)

−

16 dB minimum, 40 kHz to 200 kHz @ 392 kbaud

Return Loss (Relative to 135Ω)

Loop Loss

Noise Margin

Equalizer Automatic adaptive equalizer
Connector RJ-45

User's Serial Data Port Interface

Interface Type V.35, V.36/RS-422, RS-530, or X.21, in accordance with

Bit Rates

ASMi-450/768 n×64 kbps, up to 768 kbps
ASMi-450/1152 n×64 kbps, up to 1152 kbps

Interface Connectors

V.35 34-pin, female

−

16 dB minimum, 25 kHz to 317 kHz @ 584 kbaud

−

35 dB maximum at 200 kHz (392 kbaud)

−

31 dB maximum at 150 kHz (584 kbaud)

−

6 dB at 392 kbaud

−

3.3 dB for 584 kbaud

−

order

RS-530 25-pin D-type, female
RS-449/V.36 37-pin D-type, female (via adapter cable)
X.21 15-pin D-type, female

1-10 ASMi-450 Installation and Operation Manual

Ethernet Interface

Compliance IEEE 802.3
Interface Type 10BaseT for use on UTP and STP media
Interface Connector RJ-45 shielded eight-pin connector
Internal Bridge Remote MAC-layer bridge with self-learning

Indicators

−

User's Serial Data Port

Ethernet Port

HDSL Line

Transmit Data (TD)

−

Receive Data (RD)

−

Link status

−

Collision indicator

−

Transmit and receive data activity

−

LOS (loss of synchronization)

−

QLTY (good quality)

Introduction

−

Status

Diagnostics

Loopbacks

Timing Modes

Central Unit

Remote Unit Loopback timing, derived from incoming HDSL receive

Front Panel Controls

LCD 2×16 characters
Push-buttons CURSOR, SCROLL, ENTER

Control Port

TEST

−

ALARM

−

Local loopback on the user's serial data port of the local
ASMi-450

−

Remote loopback on the user's serial data port of the
remote ASMi-450

−

Internal timing, derived from local oscillator

−

External timing, locked to user's port receive clock

clock

Interface ITU-T Rec. V.24/EIA RS-232, asynchronous DCE interface

for direct connection of control terminal

Data Rate 300, 1200, 2400, 9600, with Autobaud option

ASMi-450 Installation and Operation Manual 1-11

Introduction

−

Word Format

Connector 9-pin D-type, female

Physical Characteristics

Depth 243 mm (9.5")
Width 215 mm (8.5")
Height 43 mm (1.7")
Weight 1.5 kg (3.5 lb.)

Power

AC Source 110V to 240VAC, 47 to 63 Hz, 5W

One start bit

−

7 or 8 data bits

−

Parity: none, odd, or even

−

One stop bit

DC Source -48VDC

Environment

Operating Temperature 0 to 50°C (32 to 122°F)
Relative Humidity Up to 90%, non-condensing

1-12 ASMi-450 Installation and Operation Manual