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MSL-88-Port SHDSL Module

Megaplex-2100/2104 Version 12

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Innovative Access Solutions

MSL-8 8-Port SHDSL Module

Megaplex-2100/2104 Version 12

Installation and Operation Manual

Notice

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

Right, title and interest, all information, copyrights, patents, know-how, trade secrets and other intellectual property or other proprietary rights relating to this manual and to the MSL-8 and any software components contained therein are proprietary products of RAD protected under international copyright law and shall be and remain solely with RAD.

MSL-8 is a registered trademark of RAD. No right, license, or interest to such trademark is granted hereunder, and you agree that no such right, license, or interest shall be asserted by you with respect to such trademark.

You shall not copy, reverse compile or reverse assemble all or any portion of the Manual or the MSL-8. You are prohibited from, and shall not, directly or indirectly, develop, market, distribute, license, or sell any product that supports substantially similar functionality as the MSL-8, based on or derived in any way from the MSL-8. Your undertaking in this paragraph shall survive the termination of this Agreement.

This Agreement is effective upon your opening of the MSL-8 package and shall continue until terminated. RAD may terminate this Agreement upon the breach by you of any term hereof. Upon such termination by RAD, you agree to return to RAD the MSL-8 and all copies and portions thereof.

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

International Headquarters RAD Data Communications Ltd.

24 Raoul Wallenberg Street Tel Aviv 69719, Israel Tel: 972-3-6458181 Fax: 972-3-6498250, 6474436 E-mail: [email protected]

North America Headquarters RAD Data Communications Inc.

900 Corporate Drive Mahwah, NJ 07430, USA Tel: (201) 5291100, Toll free: 1-800-4447234 Fax: (201) 5295777 E-mail: [email protected]

© 1988–2007 RAD Data Communications Ltd. Publication No. 764-223-10/07

mailto:[email protected]


MSL-8 MP-2100/2104 Ver. 12 1

Quick Start Guide

If you are familiar with the MSL-8 modules, use this guide to prepare it for operation.

1. Preliminary Preparations

1. Insert the module in the assigned I/O slot.

2. Refer to the site installation plan, identify the cable intended for connection to the MSL-8 connector, and connect the cable as explained below:

Connect the 40-pin connector of the CBL-MSL8-SCS40/RJ45M cable to the MSL-8 front panel connector.

Connect the RJ-45 plug of each port (the plugs are marked CH-1 to CH-8) to the prescribed user’s equipment or patch panel connector.

2. Configuration Procedure

Configure each port using the command DEF CH SS *, where SS is the module slot number. The configuration parameters of the MSL-8 ports and the allowed range of values of each parameter are listed below.

External Port Parameters

Parameter Values

SHDSL Mode STU-C

STU-R

Max BW 3×64=192 to 32×64=2048

Far End Device Megaplex

Other

ASMi-52

TS0 over DSL

(for G.732N only)

LOOPED

TRANSPARENT

Transmission Mode ANNEX A

ANNEX B

Quick Start Guide Installation and Operation Manual

2 MSL-8 MP-2100/2104 Ver. 12

Parameter Values

TS Compaction Mode NO MAPPING

LOW TS MAPPING

SPARE MAPPING

Num Of Ts For First Bundle 0, 1, 2, … 32

Power Backoff (dB) 0 to 31

Attenuation Threshold (dB) 0 to 127

SNR Margin Threshold (dB) 0 to 15

Remote Power Backoff DISABLE

ENABLE

Remote Attenuation Threshold

(for ASMi-52 only)

0 to 127

Remote SNR Margin

Threshold (for ASMi-52 only)

0 to 15

Remote Current SNR Margin

(for ASMi-52 only)

DISABLE

-10 to +10

Remote Worst Case SNR

Margin (for ASMi-52 only)

DISABLE

-10 to +10

Internal Port Parameters

Parameter Range of Values

Connect YES

NO

Frame G.732N

G.732S

Sig. Profile

(for G.732S only)

1 through 5

Idle Code 00 to FF (hexa), FF

Do not use 00, 08, 10, 12, 21,

24, 42, 49, 84, or 92

Redundancy N/A

Voice OOS 00 to FF (hexa)

Data OOS 00 to FF (hexa)

Remote CRC

(for ASMi-52, TS0 over DSL LOOPED and G.732N only)

NO

YES

Installation and Operation Manual Quick Start Guide

MSL-8 MP-2100/2104 Ver. 12 3

Parameter Range of Values

OOS Signaling

(for G.732S only)

FORCED IDLE

FORCED BUSY

BUSY IDLE

IDLE BUSY

Inband Management OFF

DEDICATE PPP

DEDICATE FR

Routing Protocol NONE

PROPRIETY RIP

RIP2

PROP RIP NO NMS TX

3. Assigning Timeslots

After performing the configuration of the individual module channels it is necessary to assign main link timeslots to each connected channel.

• When using the regular (BI-DIR) or the UNI-BRD TX mode, timeslot assignment is performed using the following commands:

Use the DEF TS SS:CC command to assign full timeslots.

Use the DEF SPLIT TS SS:CC:TS command to assign a fraction of a timeslot.

• When using the UNI-BRD RX mode, timeslot assignment for the receive direction is made using the dedicated routing fields of the DEF CH command.

Quick Start Guide Installation and Operation Manual

4 MSL-8 MP-2100/2104 Ver. 12

MSL-8 MP-2100/2104 Ver. 12 i

Contents

Chapter 1. Introduction 1.1 Overview....................................................................................................................1-1

Main Features.........................................................................................................1-1 1.2 Physical Description ...................................................................................................1-2 1.3 Functional Description................................................................................................1-4

Functional Block Diagram ........................................................................................1-4 TDM Interfaces...................................................................................................1-5 Routing Matrix....................................................................................................1-5 Timeslot Mapping Methods.................................................................................1-6 Link Interfaces ...................................................................................................1-7 Framer ...............................................................................................................1-7 SHDSL Modem....................................................................................................1-7 Timing Subsystem ..............................................................................................1-8 Local Management Subsystem............................................................................1-8

Internal Port Characteristics ....................................................................................1-9 Framing .............................................................................................................1-9 Handling of Timeslot 0 .......................................................................................1-9 Handling of Alarm Conditions ...........................................................................1-10

SHDSL Modem Characteristics ...............................................................................1-10 Link Setup Method ...........................................................................................1-10 SHDSL Modem Parameters ...............................................................................1-11

Payload Processing ...............................................................................................1-13 Processing of Channel-Associated Signaling...........................................................1-14 Diagnostics...........................................................................................................1-14

Performance Diagnostics..................................................................................1-14 1.4 Technical Specifications............................................................................................1-15

Chapter 2. Module Installation and Operation 2.1 Safety........................................................................................................................2-1 2.2 Installing the Module..................................................................................................2-1 2.3 Connecting Cables to the MSL-8 Module.....................................................................2-2

Connection Data.....................................................................................................2-2 Connecting Cables to the Module Ports ...................................................................2-2

2.4 Normal Indications .....................................................................................................2-3

Chapter 3. Configuration 3.1 Introduction...............................................................................................................3-1 3.2 MSL-8 Configuration Sequence...................................................................................3-1 3.3 Configuring External Port Parameters .........................................................................3-2 3.4 Configuring Internal Port Parameters ..........................................................................3-6 3.5 Assigning Timeslots....................................................................................................3-8 3.6 Displaying Module Status Information ........................................................................3-8

Table of Contents Installation and Operation Manual

ii MSL-8 MP-2100/2104 Ver. 12

Chapter 4. Troubleshooting and Diagnostics 4.1 Overview....................................................................................................................4-1 4.2 Diagnostics ................................................................................................................4-1

Loopback Functions on External Ports .....................................................................4-2 Local Port Loopback ...........................................................................................4-2 Remote Port Loopback .......................................................................................4-3 Remote Loopback on Remote Unit .....................................................................4-4

Tests and Loopbacks on Internal Ports ....................................................................4-4 Local Loopback on Selected Port Timeslots.........................................................4-5 Remote Loopback on Selected Port Timeslots.....................................................4-6

4.3 Troubleshooting Instructions......................................................................................4-7 4.4 Technical Support ......................................................................................................4-7

MSL-8 MP-2100/2104 Ver. 12 Overview 1-1

Chapter 1

Introduction

1.1 Overview

This manual describes the technical characteristics, applications, installation and operation of the MSL-8 SHDSL I/O modules for the Megaplex-2100/2104 integrated access multiplexer system.

For details regarding the integration of the MSL-8 modules in Megaplex-2100/2104 systems and systems applications, refer to the Megaplex-2100/2104 Installation and Operation Manual.

In this manual, the generic term Megaplex is used when the information is applicable to both the Megaplex-2100 and Megaplex-2104 versions. The complete equipment designation is used only for information applicable to a specific equipment version.

Main Features

MSL-8 is an I/O module using the single-pair high-speed digital subscriber line (SHDSL) technology for line transmission that provides the Megaplex-2100 with SHDSL interfaces capable of carrying E1 and fractional E1 payloads.

The type of SHDSL interfaces provided by the module: STU-C (SHDSL terminal unit – CO) or STU-R (SHDSL terminal unit – remote), as well as the bandwidth, are selected by software, and the module handles all the signal processing, framing and signaling processing tasks necessary for interfacing.

The SHDSL technology, standardized in ITU-T Rec. G.991.2, is an efficient method for transmitting full-duplex data at high rates over a single unloaded and unconditioned twisted copper pair, of the type used in the local telephone distribution plant. Therefore, SHDSL provides a cost-effective solution for short-range data transmission and last-mile applications.

MSL-8 modules can be configured by the user to operate either in accordance with ITU-T Rec. G.991.2 Annex A for compatibility with North American (or similar) networks, or Annex B for compatibility with European (and similar) networks.

Each MSL-8 module port is supported by an independent multi-rate SHDSL modem. Each modem supports user-selectable data rates in the range of 192 kbps to 2048 kbps, for a maximum payload capacity of up to 256 timeslots (16.384 Mbps) per module.

Each MSL-8 port can transfer either basic G.704 or G.704 multiframes (2 or 16 frames per multiframe, respectively), in accordance with user's selection.

Note

Chapter 1 Introduction Installation and Operation Manual

1-2 Physical Description MSL-8 MP-2100/2104 Ver. 12

MSL-8 ports can operate in a link with other MSL-8 ports, as well as with other RAD equipment having STU-R SHDSL interfaces, such as the ASMi-52 G.SHDSL Modems with Remote Management, FCD-IP, FCD-IPM CPE devices, etc. MSL-8 modules will also operate in a link with 991.2-compatible STU-R units from other vendors.

The MSL-8 ports can be operated as STU-R ports only when connected to other MSL-8 ports (configured as STU-C ports).

The module supports flexible payload routing, independently configurable for each port, at the individual timeslots (DS0) level. In this mode, individually selected timeslots (including timeslots with split assignment) are routed to other modules installed in the Megaplex-2100 chassis, via the internal TDM buses. Timeslots can be routed to any port with compatible characteristics.

The DS0 routing mode also supports unidirectional broadcast applications.

The MSL-8 module recovers the timing of each received E1 stream, and therefore can also provide chassis timing reference signals for the nodal Megaplex-2100 timing subsystem. The transmit timing of the internal ports can be locked to the Megaplex-2100 nodal timing.

1.2 Physical Description

The MSL-8 module occupies one I/O slot in the Megaplex-2100 chassis. Typical panels are shown in Figure 1-1. The module panel includes 8 status indicators (one for each port), and one 40-pin SCSI female connector for all the ports.

Figure 1-1. MSL-8 Module Panel

MSL-8

LINK

STATUS1357

2468

SHDSL

Note

Installation and Operation Manual Chapter 1 Introduction

MSL-8 MP-2100/2104 Ver. 12 Physical Description 1-3

Each port status indicator operates as follows:

• Lights steadily in red when the MSL-8 port is not synchronized to the remote unit

• Flashes in red during handshaking between the MSL-8 port and the remote unit

• Lights in green when the MSL-8 port is synchronized to the remote unit

• Off when the corresponding port is not connected.


1-4 Functional Description MSL-8 MP-2100/2104 Ver. 12

1.3 Functional Description

Functional Block Diagram

Figure 1-2 shows the functional block diagram of the MSL-8 module.

MSL-8

Link 1

RoutingMatrix

TDMBus H

Interface

TDMBus A

Interface

TDM

A B

us

TDM

H B

us

Timing andClock Signals

InternalTiming

Generator

InternalClock & TimingSignals

Main Clock

Fallback ClockClock

Generator

ClockSelection

RX Clocksfrom LinkInterfaces

Control

To Link Interfaces

Man

agem

ent B

us

LocalManagement

...

...

. . .

...

ExternalPort 1(EX1)SHDSL

Modem1

Framer 1

Link Interface 1InternalPort 1(IN1)

Link 4SHDSLModem

4Framer 4

Link Interface 4External

Port 4(EX4)

InternalPort 4(IN4)

...

Link 5

...

ExternalPort 5(EX5)SHDSL

Modem5

Framer 5

Link Interface 5InternalPort 5(IN5)

Link 8SHDSLModem

8Framer 8

Link Interface 8External

Port 8(EX8)

InternalPort 8(IN8)

...

.....

.....

.....

.....

.....

...

.....

Figure 1-2. MSL-8 Functional Block Diagram


MSL-8 MP-2100/2104 Ver. 12 Functional Description 1-5

The MSL-8 module includes the following main subsystems:

• TDM bus interfaces

• Routing (cross-connect) matrix

• Link interface subsystem

• Timing subsystem

• Local management subsystem.

TDM Interfaces

The MSL-8 module has eight independent bus interfaces that connect the module payload to the TDM of the Megaplex chassis.

The bus interfaces are used to transfer timeslots and signaling information destined to the ports located on the MSL-8 module, from the corresponding bus to the bus side of the routing matrix of the module, in accordance with the commands received from the CL module.

Routing Matrix

The MSL-8 module includes a routing matrix that controls the routing of payload within the module. The matrix routing is user-programmable, under the control of the CL module.

The CL module takes care of all the tasks necessary to enable the MSL-8 matrix to perform the desired services in accordance with the cross-connect mode selected on the module. Therefore, all the routing functions are actually performed on the CL module: the MSL-8 matrix only handles the transfer of payload between the bus side and the internal ports of the module (designated IN1 to IN8 in Figure 1-2), in accordance with the instructions received from the CL module.

Within the MSL-8, each internal (virtual) port is permanently connected to the external port (link) with the same number.

The result is that the following services are available for the traffic flowing through the module ports:

• Connection of timeslots from I/O ports (channels) or internal ports of other modules installed in the Megaplex-2100 to the desired MSL-8 link interface. When using channel-associated signaling (CAS), the matrix also routes the signaling information associated with each channel in parallel with the channel data.

• Bypassing timeslots among the MSL-8 ports, or among ports located on other modules and the ports located on the MSL-8 module.

• Unidirectional routing of timeslots, and broadcasting from one timeslot to multiple destinations.

The matrix also controls the flow of inband management traffic between the CL module and the appropriate link interfaces. As shown in Figure 1-2, the management connection uses a different communication channel and therefore does not occupy timeslots on the TDM bus.

Note

Note



In addition to payload routing, the MSL-8 routing matrix is also used to activate local and remote loopbacks at the timeslot level on the MSL-8 internal ports.

Timeslot Mapping Methods

The MSL-8 module supports the transfer of inband management traffic via dedicated timeslots, thereby enabling SNMP management from a remote location, through the SHDSL link.

To enable transfer of inband management traffic, it is necessary to dedicate a timeslot to inband management of each desired internal port.

When changing the payload data rate, the number of timeslots on the SHDSL link may increase/decrease. The resulting reassignment of timeslots may disrupt, although for a short time, the flow of management traffic.

Similar problems may occur with the signaling information carried in timeslot 16 of E1 ports using the G.704 multiframe mode.

To avoid this disruption, you can select one of the following timeslot mapping methods, independently for each port:

• No mapping: the connected timeslots of the E1 frame are placed in the SHDSL frame in consecutive timeslots, in ascending order.

For example, when 3 E1 timeslots (2, 16 and 20) are connected, they will be inserted in the payload timeslots 1, 2, and 3, respectively, of the SHDSL frame.

This mode is automatically used when connecting to an ASMi-52 modem. Note that when a new E1 timeslot, lower than the timeslots already connected, is added, the timeslots with higher numbers must be moved (reassigned): this results in a brief interruption of data transfer for the moved timeslots.

• Low timeslot mapping: the first two timeslots of the SHDSL frame are always reserved for the signaling timeslot (timeslot 16) and for the dedicated management timeslot. Therefore, the mapping of other payload timeslots starts from the third timeslot, and is inserted in consecutive timeslots according to the E1 frame order. This ensures that the signaling and dedicated timeslots will continue to function even when new timeslots are connected in the E1 frame. Service interruption might still occur when timeslots are moved, but in this case only data timeslots are moved.

This mode is recommended when working opposite FCD-IP and FCD-IPM units.

• Spare mapping: bandwidth is permanently assigned to each port on the basis of the maximum number of timeslots that are expected to be routed to each port, in accordance with the planned traffic load. This allocation is less efficient, because the number of timeslots allocated to the port includes not only timeslots actually carrying traffic, but also timeslots reserved for future growth. However, the advantage of this method is that when timeslots reserved for a port are allocated to traffic, there is no disruption to the traffic of other ports.

This mode is automatically used when connecting to an MSL-8 installed in another Megaplex-2100.



Link Interfaces

The MSL-8 modules have independently configurable link interfaces, one for each external port. Each link interface includes an E1 framer and an SHDSL modem.

The functions of the link interfaces are as follows:

• The transmit path of each interface generates the data stream in accordance with the framing mode selected by the user. The data stream may also include the signaling information in the format corresponding to the selected framing standard.

When using a framed mode, the framer also automatically adds the appropriate overhead. The resulting data stream is then sent through the SHDSL modem to the line, in accordance with the applicable standard.

• The SHDSL modem in the receive path of each interface recovers the received data stream and the associated clock. When using a framed mode, the resulting data stream is processed by the framer, which synchronizes to the frame and extracts the payload and signaling information.

In addition, the link interface collects performance diagnostic data in accordance with the applicable standards.

Framer

The framer simulates an internal E1 port toward the bus interface:

• The transmit path of the framer generates the E1 frame structure transmitted by the corresponding port, in accordance with the selected framing mode. The frame structure is generated by combining the data transferred by the MSL-8 routing matrix from the chassis TDM bus with framing overhead, and when applicable with the CAS information (timeslot 16) and the inband management data stream (received through the microprocessor interface).

Unused timeslots are filled with a user-specified idle code.

• The receive path of the framer demultiplexes the incoming E1 data stream, and extracts the payload data and the overhead data relevant to the selected framing mode. The overhead may include CAS signaling information, the contents of timeslot 0, and when applicable – the inband management data stream carried in a dedicated timeslot.

Out-of-service conditions are reported by inserting user-specified OOS codes.

The framer does not collect E1 performance statistics, because information on the transmission performance of the SHDSL link is available as part of the SHDSL modem performance monitoring functions.

SHDSL Modem

The SHDSL modem provides the interface between the framer and the equipment connected through the external line, in accordance with the user-selected mode (STU-C or STU-R).

• In the STU-C mode, the modem handles the SHDSL link activation, which includes the handshaking and synchronization processes needed to set up a link between the STU-C and the STU-R in accordance with the SHDSL



parameters selected by the user.

To minimize the bandwidth needed on the external line, and thus maximize the range, the transmit path of the SHDSL modem collects only timeslots carrying information that needs to be exchanged with the STU-R, and then adds the SHDSL overhead to form a standard SHDSL signal.

The main types of SHDSL overhead are: framing data, error detection and correction data (also used for performance monitoring), and an embedded operations channel (eoc) that enables the STU-C function to control the STU-R function of the remote equipment connected to the corresponding port. The modem then encodes the resulting data stream in accordance with the user-specified parameters (line data rate and regional characteristics), and transmits the resulting signal to the external line.

The receive path of the SHDSL modem recovers the signal transmitted by the STU-R. The recovered SHDSL signal is decoded and demultiplexed to retrieve the various types of data sent by the STU-R. The payload and E1 overhead data sent by the STU-R is provided to the receive path of the framer, which reconstructs the E1 signal.

• In the STU-R mode, the modem performs similar activities, except that its operation is coordinated by the STU-C, and the SHDSL subsystem timing is locked to the clock recovered from the line signal.

The SHDSL decoder can provide performance statistics for evaluating line transmission quality. The external SHDSL port also includes line protection circuits meeting the applicable standards.

Timing Subsystem

The timing subsystem generates the internal clock and timing signals required by the transmit path. These signals are locked to the Megaplex-2100 nodal timing.

STU-C module ports always use the Megaplex-2100 nodal timing. It is not possible to select a MSL-8 STU-C port as the timing reference for the Megaplex-2100 master (nodal) clock.

The nodal timing is transferred through the SHDSL link to the STU-R (either a MSL-8 STU-R port or another compatible equipment). An MSL-8 configured as STU-R can therefore be selected as nodal timing reference for the Megaplex-2100 in which the MSL-8 module is installed. This enables hierarchical timing dissemination within the network.

Local Management Subsystem

The local management subsystem performs two main functions:

• Controls the operation of the various circuits located on the MSL-8 module in accordance with the commands received from the CL module through the Megaplex-2100 management channel.

The management subsystem in an MSL-8 module configured as STU-C also controls the operation of the STU-R connected to it, by transmitting the operational parameters selected by the local user to the STU-R SHDSL management subsystem, through the eoc. This is sufficient for controlling an ASMi-52 modem, but STU-R modules cannot be configured via the eoc.



• Stores the application software of the MSL-8 module. The software can be updated through the CL module.

• Controls the routing of management traffic through the desired link interfaces, in accordance with the management mode selected by the user for each link interface.

RAD equipment with E1 interfaces can also be managed inband, using a dedicated timeslot, by the same network management system that manages the Megaplex-2100 unit, for example, RADView.

To maintain the connectivity of the management link when the E1 link is provided through the MSL-8 module by an SHDSL port, it is not possible to use the SHDSL eoc. Therefore, inband management through a dedicated timeslot must be enabled for the corresponding SHDSL port.

Internal Port Characteristics

Framing

The internal E1 link ports can be independently configured in accordance with the desired ITU-T framing mode and signaling formats:

• Basic G.704 framing (identified as G.732N). This framing mode can be used for applications that require CCS.

• G.704 framing with timeslot 16 multiframe (identified as G.732S). This framing mode (referred to as G.704 multiframe mode) is used for applications that require CAS.

The framing mode can be independently selected for each internal E1 port of the MSL-8 module.

Handling of Timeslot 0

To meet various systems requirements, you can select the handling method of timeslot 0 of an E1 stream by each MSL-8 port. Two options are available:

• Terminate (loop back) timeslot 0. This option is available in the basic G.704 mode only.

• Transfer timeslot 0 transparently through the SHDSL link, down to the E1 port of the equipment unit connected to the remote ASMi-52 unit. This option is available in both G.704 framing modes.

For compatibility with ASMi-52 modems, the actual location at which timeslot 0 is looped back can be configured by the user:

• For ASMi-52 modem versions without E1 user port (or with the E1 port unconnected), the only option is to loop back the timeslot at the input of the SHDSL modem.

• For ASMi-52 modem versions with E1 user port, it is also possible to loop back timeslot 0 at the remote modem. In this case, it is necessary to enable the CRC-4 function on the ASMi-52 E1 user port: in this way, the transmission performance on the segment between the user’s equipment and the ASMi-52 E1 port is separately monitored.

Note



Handling of Alarm Conditions

The internal E1 ports support two types of indications in the individual timeslots: idle timeslots and out-of-service (OOS) indications.

• Idle Timeslot Indication. A special code can be transmitted in empty timeslots (timeslots which do not carry payload).

• OOS Indications. The OOS code is inserted in individual timeslots to signal the equipment routed to one of the E1 ports of the module that the link connected to the external port is out-of-service (e.g., because of loss of frame synchronization).

The idle code and OOS indications can be independently configured for each MSL-8 port. Moreover, separate OOS codes can be transmitted in the timeslots, in accordance with the type of payload carried by each timeslot (voice or data); when the G.704 multiframe mode is used, the signaling OOS code can also be selected.

SHDSL Modem Characteristics

Link Setup Method

SHDSL modems use trellis-coded pulse-amplitude modulation (TC-PAM) to generate a baseband line signal capable of carrying high data rates within a relatively narrow bandwidth, suitable for full-duplex communication at high payload data rates (up to 2.048 Mbps for MSL-8 ports) over a single unloaded and unconditioned 26 AWG (0.4 mm) copper twisted pair.

This capability is made possible by advanced digital signal processing techniques, used together with a special link activation process. This process has three main steps:

1. Analysis of line transmission characteristics (line probing) whenever a link must be setup between two SHDSL modems.

2. Exchanging of transmission parameters (handshaking) between the two modems.

3. Transmission of special signals that enable synchronization of the two modems.

After synchronization, the modems support transmission of payload, as well as an eoc. The total overhead carried by an SHDSL signal is always 8 kbps.

The MSL-8 front panel indicators enable the user to visually monitor the state of each module port during the link setup process (see Section 1.2).

This process must be correctly coordinated, and therefore ITU-T Rec. G.991.2 specifies that the modem configured as STU-C will serve as a master unit which initiates and controls the link activation process, and manages the communication through the eoc. The other modem, configured as STU-R, operates as a slave and cooperates with the STU-C as required to setup the link in accordance with the capabilities determined by the STU-C.

Note however that MSL-8 STU-R ports do not accept configuration commands through the eoc, but only through the Megaplex-2100 system management.



The flow of the timing reference through the link is always from the STU-C to the STU-R.

To ensure interoperability with RAD equipment and simplify the selection of certain operational parameters, one of MSL-8 port configuration parameters is used to specify the type of equipment connected to the far end of the SHDSL line: another Megaplex unit, an ASMi-52 modem, or other equipment (either from RAD or from other vendors).

A MSL-8 module can operate as STU-R only if the far-end equipment is another Megaplex (which must include a MSL-8 module serving as STU-C).

SHDSL Modem Parameters

You must specify the following set of SHDSL modem parameters for each MSL-8 STU-C port:

• Maximum bandwidth. The SHDSL modem of each port supports payload (user) rates which are multiples of 64 kbps (n × 64 kbps), where n is in the range of 3 to 32, corresponding to bit rates of 192 to 2048 kbps. The selected rate is automatically configured on the STU-R, except in case the STU-R is another MSL-8 module.

The SHDSL modems use the maximum bandwidth to setup a link that supports the specified rate. Because of the modulation method used by SHDSL modems, a lower rate enables operation over longer ranges. It also reduces the power consumption of the MSL-8 module.

The minimum payload data rate supported by an SHDSL signal, however, is 192 kbps (corresponding to three timeslots on the SHDSL line), which results, together with the SHDSL overhead (8 kbps) in a minimum line rate of 200 kbps. Therefore, you cannot select data rates lower than 192 kbps.

The maximum bandwidth specified by you is used to set up a link capable of supporting the specified payload rate: if the number of timeslots routed to the corresponding module port is lower than the maximum rate, any unused timeslots in the SHDSL signal frame is filled with the idle timeslot code.

When selecting the minimum data rate, make sure to take into consideration that timeslots may also have to be allocated for one or more of the following purposes:

End-to-end transfer of timeslot 0 – when the selected timeslot 0 mode is transparent.

End-to-end transfer of the signaling timeslot (timeslot 16) – when the framing mode is G.732S (G.704 multiframe).

Management – when inband management is desired.

Therefore, you may have to add up to three timeslots to the number of timeslots assigned to payload data.

Table 1-1 lists typical MSL-8 MSL-8, MSL-8 ASMI-52, and ASMI-52 ASMI-52 ranges over 2-wire 26 AWG pairs versus the payload data rate, in Annex B mode. All measurement tests were carried out in an error-free environment in a test laboratory, with an accuracy of ± 10%. Note

Note



that because of the widely varying characteristics of actual twisted pairs, the actual range on any particular pair may deviate from the data presented in the table.

The ASMI-52 ASMI-52 ranges are given for reference only. For full information on the ASMi-52 modem, refer to the ASMi-52 Installation and Operation Manual.

Table 1-1. Typical MSL-8 and ASMi-52 Ranges on 26 AWG Pair (2-Wire)

MSL-8 MSL-8 MSL-8 ASMI-52 ASMI-52 ASMI-52 Data Rate

[kbps] [km] [miles] [km] [miles] [km] [miles]

64 – – – – 7.5 4.6

128 – – – – 7.0 4.3

256 6.1 3.8 6.0 3.7 6.7 4.1

384 6.0 3.7 5.9 3.7 6.5 4.0

512 5.8 3.6 5.7 3.5 6.3 3.9

1024 5.4 3.3 5.1 3.2 5.3 3.3

1536 5.5 3.4 4.3 2.6 5.0 3.1

2048 4.9 3.0 4.2 2.6 4.5 2.8

• Timeslot 0 termination. As explained in the Handling of Timeslot 0 section above, when using the basic G.704 framing mode, you can select between local termination of timeslot 0, and transparent transfer of timeslot 0 contents.

The recommended settings for RAD equipment that can be connected to MSL-8 modules are as follows:

ASMi-52 with E1 user port: either transparent or looped back, as required

ASMi-52 without E1 user port, for example, single-channel ASMi-52 with high-speed data user port, or with LAN and data ports: always looped back

FCD-IP, FCD-IPM: always transparent.

Contact RAD Technical Support Department for help on other equipment.

• Transmission mode. ITU-T Rec. G.991.2 specifies two sets of regional signal characteristics for SHDSL modems:

The set of characteristics specified in Annex A is required for compatibility in North American networks

The set of characteristics specified in Annex B is required for compatibility in European networks.

The same selection must be made for all the MSL-8 ports. For connections to an ASMi-52, the selection is automatically enforced on the ASMi-52.

• Power backoff. Because of the complex line signal transmitted by SHDSL modems, it may be desirable to transmit at reduced power, that is, at less

Note



than the maximum signal power allowed in accordance with the standards. You can instruct the STU-C to use the nominal transmit level, or allow backoff: in this case, you can select the maximum reduction in 1-dB steps, up to -31 dB relative to the nominal transmit level.

• Attenuation threshold. You can enable the generation of an alarm in case the attenuation value measured by the STU-C on the SHDSL link exceeds a certain value (user-selectable in 1-dB steps up to 127 dB).

• SNR margin threshold. You can enable the generation of an alarm in case the signal/noise ratio decreases below a certain value (user-selectable in 1-dB steps up to 15 dB).

When operating in a link with ASMi-52 modems, the MSL-8 ports can control several of the STU-R operational parameters via the eoc:

• Remote power backoff. The power backoff can be separately enabled/disabled for the STU-R.

• Remote attenuation threshold. A separate attenuation threshold value can be selected for the STU-R.

• Remote SNR margin threshold. The SNR margin threshold of the ASMi-52 can be separately selected.

• Remote current SNR margin. You can decide whether to specify an SNR margin for the ASMi-52, and its value. The current SNR margin is specified relative to the noise level measured during the SHDSL line activation process. This margin can be set in 1-dB steps, within the range of -10 to +10 dB.

• Remote worst case SNR margin. As an alternative to using the current SNR margin during the line activation process, you can specify a worst-case SNR margin for the ASMi-52. The worst-case SNR margin is specified relative to the worst-case crosstalk noise specified in ITU-T Rec. G.991.2. This margin can be set in 1-dB steps, within the range of -10 to +10 dB.

For background information on SHDSL, refer to the Megaplex-2100/2104 Installation and Operation Manual.

Payload Processing

The MSL-8 modules support three main types of payload. The payload type is user-selectable per timeslot:

• Data timeslots: timeslots which are transparently transferred from port to port. In general, it is assumed that no CAS is associated with data timeslots.

• Voice timeslots: timeslots carrying PCM-encoded payload with A-law companding.

In general, CAS is always associated with voice timeslots.

• Management timeslots: one timeslot of any port can be assigned to carry management traffic. Such timeslots are always directed to the CL management subsystem, for processing.

The flow of payload carried by data and voice timeslots is normally bidirectional (full duplex connection). However, as explained in the Megaplex-2100/2104 Installation and Operation Manual, it is also possible to define unidirectional flows



(unidirectional broadcasts), from one source (a timeslot of a source port) to multiple destinations (each destination being a selected timeslot of another port).

Processing of Channel-Associated Signaling

The MSL-8 modules support channel-associated signaling. For flexibility, the user can specify the following signaling format conversions:

• Conversion of signaling information received through a link, in order to match any specific internal Megaplex signaling interpretation conventions.

• Conversion of the internal signaling information to the format used by the equipment connected to Megaplex links.

Each link can use different receive and transmit translation rules. These translation rules are defined by means of signaling profiles, explained in the Megaplex-2100/2104 Installation and Operation Manual.

A profile enables the user to select the translation of each individual signal bit. The available selections are A, B, C, D (value copied from the corresponding incoming bit), ~A, ~B, ~C, ~D (inverted value of corresponding incoming bit), 0 (always 0), and 1 (always 1).

In addition to the translation of individual bits, the receive path conversion section can also be used to define the signaling bit patterns that indicate the busy and idle states.

Diagnostics

The MSL-8 module panel includes indicators that display the status of each line interface (see Section 1.2).

The MSL-8 module includes self-test upon power-up, and additional diagnostic functions at the port and timeslot level that can be controlled by the operator using the Megaplex-2100 system management.

• At the external port level, the testing capabilities include local and remote loopbacks on each desired port.

• At the internal port level, the testing capabilities include local and remote loopbacks on individual timeslots.

Performance Diagnostics

The MSL-8 ports support the collection of performance diagnostics in accordance with the requirements of ITU-T Rec. G.991.2.


MSL-8 MP-2100/2104 Ver. 12 Technical Specifications 1-15

1.4 Technical Specifications

External Port Characteristics

Number of Ports 8

Port Interface Type SHDSL

Applicable Standards ITU-T Rec. G.991.2

Port Type Software configurable for all the ports:

• STU-C – default mode

• STU-R – selectable only when connecting to another MSL-8 installed in a Megaplex-2100 unit

Line Type Single unloaded, unconditioned copper twisted pair, 26 AWG or thicker

Nominal Line Impedance 135Ω

Range See Table 1-1

Line Connector 40-pin SCSI female connector for all the ports. Adapter cables available from RAD

Type and Bit Rate E1, 2.048 Mbps Internal Port Characteristics

Framing • Basic G.704 framing (G732N)

• Timeslot 16 multiframe (G732S)

Timing Port Timing • STU-C: locked to the Megaplex nodal clock

• STU-R: locked to the line signal received from the STU-C

Diagnostics External Port Loopbacks • Local loopback on each external port

• Remote loopback on each external port

Internal Port Loopbacks • Local loopback per timeslot

• Remote loopback per timeslot

Performance Monitoring In accordance with ITU-T Rec. G.991.2


1-16 Technical Specifications MSL-8 MP-2100/2104 Ver. 12

Indicators Status Indicator per Link Dual-color indicator:

• Lights steadily in red when the MSL-8 port is not synchronized to the remote unit

• Flashes in red during handshaking between the MSL-8 port and the remote unit

• Lights in green when the MSL-8 port is synchronized to the remote unit

• Off when the corresponding port is not connected

Configuration Programmable via Megaplex management system

MSL-8 MP-2100/2104 Ver. 12 Installing the Module 2-1

Chapter 2

Module Installation and Operation

This chapter provides installation and operation instructions for the MSL-8 module.

The information presented in this chapter supplements the general Megaplex installation, configuration and operation instructions contained in the Megaplex-2100/2104 Installation and Operation Manual.

2.1 Safety

Before performing any internal settings, adjustment, maintenance, or repairs, first disconnect all the cables from the module, and then remove the module from the Megaplex-2100 enclosure. No internal settings, adjustment, maintenance, and repairs may be performed by either the operator or the user; such activities may be performed only by a skilled technician who is aware of the hazards involved. Always observe standard safety precautions during installation, operation, and maintenance of this product.

The MSL-8 module contains components sensitive to electrostatic discharge (ESD). To prevent ESD damage, always hold the module by its sides, and do not touch the module components or connectors.

2.2 Installing the Module

All the module functions are controlled by software, and therefore no preliminary preparations are required before installing the module.

Refer to the system installation plan and insert the module into the prescribed I/O slot of the Megaplex chassis.

The module starts operating as soon as it is plugged into an operating chassis. At this stage, ignore any alarm indications.

Warning

Caution

Chapter 2 Module Installation and Operation Installation and Operation Manual

2-2 Connecting Cables to the MSL-8 Module MSL-8 MP-2100/2104 Ver. 12

2.3 Connecting Cables to the MSL-8 Module

Connection Data

All the SHDSL ports of the MSL-8 module are terminated in a 40-pin SCSI female connector, designated SHDSL.

A 2-meter long adaptor cable, CBL-MSL8-SCS40/RJ45M, can be ordered from RAD, for connecting to the module SHDSL interfaces.

Figure 2-1 shows the cable construction. Table 2-1 presents the cable wiring and identifies the interface connector pin assignment.

CB

L-M

SL

8-S

C40

RJ4

5M

Ch. 1

Ch. 2

Ch. 3

Ch. 4

Ch. 6

Ch. 7

Ch. 8

Ch. 5

Figure 2-1. CBL-MSL8-SCS40/RJ45M Cable

Connecting Cables to the Module Ports

Using the site installation plan, identify the cable intended for connection to the MSL-8 connector, and connect the cable to the module connector as explained below.

To connect the cable to the module:

1. Connect the 40-pin connector of the CBL-MSL8-SCS40/RJ45M cable to the module front panel connector.

2. Connect the RJ-45 plug of each port (the plugs are marked CH-1 to CH-8) to the prescribed user’s equipment or patch panel connector. Insulate unused connectors, to prevent accidental short-circuiting of their exposed contacts to metallic surfaces.

Installation and Operation Manual Chapter 2 Module Installation and Operation

MSL-8 MP-2100/2104 Ver. 12 Normal Indications 2-3

Table 2-1. CBL-MSL8-SCS40/RJ45M Cable Wiring

40-Pin SCSI

Connector

40-Pin SCSI

Connector Channel RJ-45

Connector Pin Function

RJ-45

Connector

Pins

Channel RJ-45

Connector Pin Function

RJ-45

Connector

Pins

1 RX Ring 1 10 RX Ring 1

2 RX Tip 2 11 RX Tip 2

22 TX Ring 4 30 TX Ring 4 1 CH-1

21 TX Tip 5

5 CH-5

29 TX Tip 5




23 TX Tip 5

6 CH-6

31 TX Tip 5




25 TX Tip 5

7 CH-7

33 TX Tip 5




27 TX Tip 5

8 CH-8

36 TX Tip 5

2.4 Normal Indications

The status of each MSL-8 link is indicated by a separate indicator.

During normal operation, after communication with the remote equipment is established, the port indicators of the MSL-8 module must light steadily in green (however, if a port is configured as the standby port in a redundancy pair, its indicator flashes in green).

If the other communication equipment on the link is not yet operative, the port indicator will light in red. The indicator must turn green (or flash in green) as soon as the link with the remote equipment is established.

The indicators of ports not configured as connected are off.

Chapter 2 Module Installation and Operation Installation and Operation Manual

2-4 Normal Indications MSL-8 MP-2100/2104 Ver. 12

MSL-8 MP-2100/2104 Ver. 12 MSL-8 Configuration Sequence 3-1

Chapter 3

Configuration

3.1 Introduction

This chapter provides specific configuration information for the MSL-8 module.

The configuration activities are performed by means of the management system used to control the Megaplex-2100 unit. The instructions appearing in this chapter assume that you are familiar with the management system being used:

• Supervision terminal or Telnet. Refer to the Megaplex-2100/2104 Installation and Operation Manual for instructions.

• Network management system, e.g., the RADview network management system (refer to the RADview User's Manual for instructions).

For general instructions, additional configuration procedures, and background information, refer to the Megaplex-2100/2104 Installation and Operation Manual.

3.2 MSL-8 Configuration Sequence

To configure an MSL-8 module and put it into service:

1. Configure the module port parameters using the DEF CH SS * command.

2. When necessary, modify the system timing reference using the DEF SYS command.

3. Configure timeslot utilization for each module port using the DEF TS and DEF SPLIT TS commands.

Before configuring the module, it is necessary to define the appropriate signaling profiles, using the DEF PROFILE command.

Make sure to plan ahead the configuration sequence, because Megaplex-2100 databases can be updated only after correctly completing the configuration activities: any sanity error will prevent saving the changes to the database being modified. For example, a common cause of sanity errors that may prevent updating the database is that timeslots need to be assigned to ports of other modules that will be served to the MSL-8 ports.

Note

Note

Chapter 3 Configuration Installation and Operation Manual

3-2 Configuring External Port Parameters MSL-8 MP-2100/2104 Ver. 12

3.3 Configuring External Port Parameters

The external port parameters are explained in Table 3-1.

Table 3-1. External Port Parameters

Parameter Function Values

SHDSL Mode Selects the port operating mode.

This parameter can be changed only

when the Far End Device is Megaplex;

for the other Far End Device selections,

the mode is always STU-C

STU-C – SHDSL terminal unit – CO mode.

STU-R – SHDSL terminal unit – remote.

This option is available only when the equipment

connected to the far end of the line is another

MSL-8 module installed in a Megaplex-2100.

Default: STU-C

Max BW Selects the maximal data rate that can

be transported by the port

Multiples of 64 kbps (n × 64 kbps, where n is in

the range of 3 to 32), corresponding to bit rates

of 192 to 2048 kbps.

Make sure to select a data rate consistent with

the total number of timeslots to be transmitted

to the remote equipment. You must take into

consideration the payload data rate, and then

add 64 kbps for each timeslot needed for one of

the following purposes:

• Management

• For transparently transferring the signaling

timeslot

• For transparently transferring timeslot 0.

Default: 3 × 64 (192 kbps)

Far End Device Specifies the type of equipment

connected to the far end of the SHDSL

line.

MSL-8 uses this information to select

the best configuration for optimal

interoperability with RAD equipment

Megaplex – MSL-8 module installed in the

Megaplex unit.

Other – Other types of equipment, for example,

DXC, FCD, equipment from other vendors, etc.

ASMi-52 – ASMi-52 modem with a single user

port.

Default: Megaplex

Installation and Operation Manual Chapter 3 Configuration

MSL-8 MP-2100/2104 Ver. 12 Configuring External Port Parameters 3-3


TS0 over DSL Selects the handling of timeslot 0 by the

corresponding port.

LOOPED – Local termination of timeslot 0. This

option can be selected only when

Frame=G.732N. Always select this option when

the far end equipment connected to the port is

an ASMi-52 (Far End Device is ASMi-52 without

E1 ).

TRANSPARENT – Transparent transfer of timeslot

0 through the SHDSL link (in this case, timeslot 0

is terminated by the remote equipment). When

selecting the port bandwidth, make sure to

assign an additional timeslot for transferring

timeslot 0.

Default: TRANSPARENT

Transmission

Mode

Selects the set of regional-dependent

parameters used by the module SHDSL

modems.

All the module ports use the same mode

(the last selection before database

updating is retained and applied to all

the ports)

ANNEX A – Compliance with Annex A of ITU-T

Rec. G.991.2, required for compatibility in North

American networks.

ANNEX B – Compliance with Annex B of ITU-T

Rec. G.991.2, required for compatibility in

European networks.

Default: ANNEX A

TS Compaction

Mode

Controls the mapping of the connected

E1 port timeslots into the SHDSL

frames.

NO MAPPING – The connected timeslots of the

E1 frame are placed in the SHDSL frame in

consecutive timeslots, in ascending order.

Note that when a new E1 timeslot, lower than

the timeslots already connected, is added, the

timeslots with higher numbers must be moved

(reassigned): this results in a brief interruption

of data transfer for the moved timeslots.

Use this selection for Far End Device=ASMi-52.

LOW TS MAPPING – The first two timeslots of the

SHDSL frame are reserved for the signaling

timeslot (timeslot 16) and the dedicated

management timeslot. The payload starts from

the third timeslot, and is inserted in consecutive

timeslots according to the E1 frame order.

This ensures that the signaling and dedicated

timeslots will continue to function even when

new timeslots are connected in the E1 frame.

Service interruption might still occur when

timeslots are moved, but in this case only data

timeslots are moved.

Use this selection for Far End Device=Other (for

example, FCD-IP).


3-4 Configuring External Port Parameters MSL-8 MP-2100/2104 Ver. 12


SPARE MAPPING – bandwidth is permanently

assigned to each port on the basis of the

maximum number of timeslots that are expected

to be routed to each port, in accordance with

the planned traffic load. This allocation is less

bandwidth-efficient, because the number of

timeslots allocated to the port includes not only

timeslots actually carrying traffic, but also

timeslots reserved for future growth. However,

the advantage of this method is that when

timeslots reserved for a port are allocated to

traffic, there is no disruption to the traffic of

other ports.

Default: NO_MAPPING

Use this selection for Far End Device=Megaplex.

Num Of Ts For

First Bundle

Selects the number of payload timeslots

to be connected to channel 1 of the

remote ASMi-52 unit.

This parameter is displayed only when

the Far End Device is a dual channel

unit, that is, ASMi-52 E1 + DATA,

ASMi-52 E1 + LAN or ASMi-52 LAN +

DATA.

Do not include in this number timeslot

0, nor timeslot 16 when using G.732S,

but do include the inband management

timeslot (needed to enable inband

management traffic to reach a remote

E1 port)

The available range is 0 to 32 timeslots.

Default: 2

Power Backoff

(dB)

Controls the use of transmit power

backoff.

Power backoff is used to reduce the

transmit power below the nominal value

specified in the standards: this reduces

distortion in repeaters as well as the

interference caused by your signal to

other equipment using pairs in the same

cable, without degrading the link

transmission quality

The allowable range is 0 to 31.

0 means that the nominal transmit power is

always used. Any other value indicates the

maximum power backoff value, in dB below the

nominal transmit power specified in the

standards.

Default: 0

Attenuation

Threshold (dB)

Controls the generation of an alarm in

case the attenuation measured on the

SHDSL link exceeds a certain value

The allowable range is 0 to 127 (the number

specifies the maximum value, in dB).

Default: 0

SNR Margin

Threshold (dB)

Controls the generation of an alarm in

case the signal/noise measured on the

SHDSL link decreases below a certain

value (margin)

The allowable range is 0 to 15.

Default: 0


MSL-8 MP-2100/2104 Ver. 12 Configuring External Port Parameters 3-5


Remote Power

Backoff

Controls the use of transmit power

backoff at the STU-R.


Far End Device is an ASMI-52 version

DISABLE – The use of power backoff at the

STU-R is disabled.

ENABLE – The use of power backoff is enabled.

Default: ENABLE

Remote

Attenuation

Threshold

Selects the attenuation threshold at the

STU-R. If the attenuation measured by

the STU-R on the SHDSL link exceeds

the specified value, an alarm is

generated.


the Far End Device is an ASMI-52 version



Default: 0

Remote SNR

Margin

Threshold

Selects the SNR margin threshold at the

STU-R. If the attenuation measured by

the STU-R on the SHDSL link exceeds

the specified value, an alarm is

generated.


the Far End Device is an ASMI-52 version



Default: 0

Remote Current

SNR Margin

Specifies the target margin for the

signal-to-noise ratio measured by the

STU-R relative to the current noise level,

that is, the noise level measured

measured by the STU-R.

Alternatively, line activation may be

performed in accordance with the

Remote Worst Case SNR Margin value.

This parameter is used during SHDSL line

activation, and is displayed only when

the Far End Device is an ASMI-52

version.

• To use the signal-to-noise ratio measured

relative to the current noise level during

SHDSL line activation, select the desired

value, in the range of -10 to +10 dB.

• To disable the use of the signal-to-noise ratio

measured relative to the current noise level,

select DISABLE.

Default: DISABLE

Remote Worst

Case SNR Margin

Specifies the target margin for the

signal-to-noise ratio measured by the

STU-R relative to the reference

worst-case near-end crosstalk noise

specified in ITU-T Rec. G.991.2.

Alternatively, line activation may be

performed in accordance with the

Remote Current SNR Margin value.

This parameter is used during SHDSL line

activation, and is displayed only when

the Far End Device is an ASMI-52

version.

• To use the signal-to-noise ratio measured

relative to the near-end crosstalk during

SHDSL line activation, select the desired

value, in the range of -10 to +10 dB.

• To disable the use of the signal-to-noise ratio

measured relative to crosstalk and use the

signal-to-noise ratio measured relative to the

current noise level, select DISABLE.

Default: DISABLE


3-6 Configuring Internal Port Parameters MSL-8 MP-2100/2104 Ver. 12

3.4 Configuring Internal Port Parameters

Table 3-2 lists the internal port parameters.

Table 3-2. Internal Port Parameters


Connect Determines whether the E1 port is

connected to an internal bus

YES E1 port is connected.

NO E1 port is disconnected. You can still

configure the E1 port, so that it will

operate when needed.

Default: NO

Frame Selects the port framing mode.

G.732N – The port handles the traffic as a basic

G.704 framed signal.

Always select this option when the Far End

Device selected for the corresponding external

port is ASMi-52 with a LAN or synchronous port.

G.732S – The port handles the traffic as a G.704

framed signal with multiframe structure based

on timeslot 16.

This option should be used when the Far End

Device selected for the corresponding external

port is an ASMi-52 version with E1 user port,

and the port is connected.

Default: G.732S

Sig. Profile Selects the signaling profile that

specifies the interpretation of the

signaling information transmitted and

received by the corresponding link.

The number of the profile appears in

brackets, after the optional profile

name.

The signaling profiles and their names

are defined by means of the DEF PROFILE command

The available range is 1 through 5.

Default: 1

Idle Code Selects the code transmitted to fill idle

(unused) timeslots in the frames

transmitted through this port.

The available selections are 00 to FF (hexa).

Do not select 00, 08, 10, 12, 21, 24, 42, 49, 84,

or 92 as the idle code.

Default: FF

Redundancy Controls the use of port redundancy -

reserved for future versions

N/A

Voice OOS Selects the code transmitted during

out-of-service periods on the timeslots

defined as voice timeslots


Default: 00


MSL-8 MP-2100/2104 Ver. 12 Configuring Internal Port Parameters 3-7


Data OOS Selects the code transmitted during

out-of-service periods on the timeslots

defined as data timeslots


Default: 00

Remote CRC Enables the CRC-4 error detection

capability at the remote ASMi-52 unit.

This function is used for performance

monitoring, and is available only when

the ASMi-52 includes an E1 user port.


the Far End Device selected for the

corresponding external port is an ASMi-

52 version with E1 user port, and TS0

over DSL is LOOPED

NO – the CRC-4 option is disabled.

YES – The CRC-4 option is enabled.

Default: NO

OOS Signaling

Determines the state of the signaling

bits during out-of-service periods.

This parameter is displayed only after

selecting G.732S framing

FORCED IDLE – The signaling bits are forced to

the idle state during out-of-service periods.

FORCED BUSY – The signaling bits are forced to

the busy state during out-of-service periods.

BUSY IDLE – The signaling bits are forced to the

busy state for 2.5 seconds, then switch to the

idle state until the out-of-service condition

disappears.

IDLE BUSY – The signaling bits are forced to the

idle state for 2.5 seconds, then switch to the

busy state until the out-of-service condition

disappears.

Default: FORCED IDLE

Inband

Management

Controls the transfer of inband

management traffic through this port.

OFF – The transfer of management traffic is

disabled.

DEDICATE PPP – The transfer of management

traffic is enabled. The management traffic is

transferred in a dedicated timeslot, using

synchronous PPP over HDLC encapsulation.

DEDICATE FR – The transfer of management

traffic is enabled. The management traffic is

transferred in a dedicated timeslot, using

Frame Relay encapsulation (under DLCI 100) in

accordance with RFC 2427.

Default: OFF


3-8 Displaying Module Status Information MSL-8 MP-2100/2104 Ver. 12


Routing Protocol When the transfer of inband

management traffic is enabled,

controls the transmission of RIP2

routing tables.

Transmitting these tables enables

other equipment to use the RIP2

routing protocol for management

traffic carried through this port.

This parameter is not displayed when

Inband Management is OFF

NONE – Routing of management traffic is not

supported.

PROPRIETY RIP – Management traffic is routed

using RAD proprietary routing protocol.

RIP2 – In addition to the RAD proprietary

routing protocol, RIP2 routing is also

supported.

PROP RIP NO NMS TX – Same as RIP2, but the

routing tables transmitted through this port do

not include information on the network

management stations (NMS) learned by the

Megaplex-2100.

Default: NONE

3.5 Assigning Timeslots

After performing the configuration of the individual module channels it is necessary to assign main link timeslots to each connected channel.

• When using the regular (BI-DIR) or the UNI-BRD TX mode, timeslot assignment is performed using the following commands:

Use the DEF TS SS:CC command to assign full timeslots.

Use the DEF SPLIT TS SS:CC:TS command to assign a fraction of a timeslot.

• When using the UNI-BRD RX mode, timeslot assignment for the receive direction is made using the dedicated routing fields of the DEF CH command.

The timeslot assignment for both modes is explained in the Megaplex-2100/2104 Installation and Operation Manual.

3.6 Displaying Module Status Information

You can read the type of interface and the configuration parameters of the MSL-8 module using the DSP ST CH SS command. For a general description of this command, refer to Appendix F of the Megaplex-2100/2104 Installation and Operation Manual.

After entering the DSP ST CH SS command, you will see the first section of the module status data form. This section displays the SHDSL synchronization state for each module port. A typical screen is shown below:


MSL-8 MP-2100/2104 Ver. 12 Displaying Module Status Information 3-9

Module : MSL-8/E1 Hardware Config/Status : ------------------------ Port EX1 : Shdsl State: DATA MODE

Press <Enter> to display the port configuration. For a description of the displayed parameters, refer to Table 3-2.


3-10 Displaying Module Status Information MSL-8 MP-2100/2104 Ver. 12

MSL-8 MP-2100/2104 Ver. 12 Diagnostics 4-1

Chapter 4

Troubleshooting and Diagnostics

4.1 Overview

This chapter explains the specific diagnostic functions of the MSL-8 module. The chapter also includes troubleshooting instructions.

The alarm messages generated by the MSL-8 modules are explained in the Megaplex-2100/2104 Installation and Operation Manual.

The diagnostic information presented in this chapter supplements the general Megaplex diagnostics instructions contained in the Megaplex-2100/2104 Installation and Operation Manual.

If you need additional support for this product, see Section 4.4 for technical support information.

4.2 Diagnostics

The MSL-8 modules support test and loopback functions at two levels:

• External port level. The external port diagnostic functions include the following loopbacks:

Local loopback: this loopback returns the SHDSL port transmit signal to the input of the port receive path

Remote loopback: this loopback returns the SHDSL port receive signal toward the remote Megaplex.

Remote loopback on remote unit: when operating opposite ASMi-52 modem, used to test all the circuits of the corresponding MSL-8 port, the line to the ASMi-52, and the operation of the ASMi-52.

• Internal port level. The internal port diagnostic functions include tests and loopbacks at the level of individual timeslots:

Local loopback per timeslot

Remote loopback per timeslot

The following sections explain each test and loopback supported by MSL-8 modules.

Chapter 4 Troubleshooting and Diagnostics Installation and Operation Manual

4-2 Diagnostics MSL-8 MP-2100/2104 Ver. 12

Note that the activation of a loopback disconnects the local and remote equipment served by the MSL-8. Therefore, when you initiate a loopback, you have the option to limit its duration to a selectable interval in the range of 1 through 30 minutes. After the selected interval expires, the loopback is automatically deactivated, without operator intervention. However, you can always deactivate a loopback activated on the local Megaplex before this time-out expires.

When using inband management, always use the time-out option; otherwise, the management communication path may be permanently disconnected.

The connection of a loopback on the master (active) link of a redundant pair may cause the activation (flipping) of an alternative database. To prevent database flipping, you must configure the duration of the loopback to be shorter than the out-of-service delay defined for the corresponding link fail event.

Loopback Functions on External Ports

This section describes the loopbacks supported on the external MSL-8 ports.

The external MSL-8 ports support three types of user-controlled loopbacks, which can be independently activated for each port:

• Local loopback

• Remote loopback

• Remote loopback on remote unit.

Local Port Loopback

The local port loopback is used to test the path of the signals intended for transmission through a selected MSL-8 port: this path starts at the other port(s) of the same Megaplex connected to the selected port, and continues up to the SHDSL modem serving the port. Within the tested MSL-8 module, the path includes most of the SHDSL modem circuits serving the selected port, and the operation of the routing circuits that handle the port signals within the module.

The local port loopback signal path for the MSL-8 module is shown in Figure 4-1.

As shown in Figure 4-1, when a local loopback is activated on one of the module ports, the port transmit signal is returned to the input of the same port receive path, at a point just before the line interface. The local port must receive its own signal, and thus it must be frame-synchronized.

During the local port loopback, the remote equipment does not receive a valid SHDSL signal, and therefore will lose synchronization. This is normal, and does not indicate a problem.

After the local loopback is deactivated, the SHDSL subsystem must synchronize again, and therefore you will see the sequence of port synchronization indications at both the local and the remote ports.

In addition, each I/O module connected to the corresponding port must also receive its own signal: in general, the result is that these modules are synchronized and do not generate alarm indications. Note however that there are

Caution

Note

Installation and Operation Manual Chapter 4 Troubleshooting and Diagnostics


modules that cannot receive their own signal, for example modules with Ethernet interfaces: these module do enter an alarm state while a local loopback is activated.

Megaplex-2100

Other PortInterface

BusInterface

.....

Port 8

Port 1

ML-8SL 1" "

.......

Figure 4-1. Local Port Loopback Signal Path

Remote Port Loopback

The remote port loopback is used to test the SHDSL modem circuits of a selected MSL-8 external port. This test also checks the transmission plant connecting the remote equipment to the corresponding port of the MSL-8 module.

The remote port loopback signal path for a typical module (MSL-8) is shown in Figure 4-2.

Megaplex-2100

Other PortInterface

BusInterface

.....

Port 8

Port 1

MSL-8

.......

Figure 4-2. Remote Port Loopback Signal Path

When a remote loopback is activated on one of the MSL-8 ports, the SHDSL modem serving that port returns the received signal toward the remote unit, via the transmit path. The received signal remains connected as usual to the receive path of the corresponding port. To correct transmission distortions, the returned signal is fully regenerated by the SHDSL modem circuits.

The remote loopback should be activated only after checking that the remote unit operates normally with local port loopback. In this case, the remote unit must receive its own signal, and thus it must be frame-synchronized. The effect on the individual modules is mixed, as explained above for the local loopback.

If the local Megaplex unit operates normally with the local port loopback, then while the remote loopback is connected the local unit should receive a valid signal, and thus it must be frame-synchronized.



The remote port loopback should be activated at only one of the two Megaplex connected in a link, otherwise an unstable situation occurs.

Remote Loopback on Remote Unit

The remote loopback on remote unit is relevant for MSL-8 ports connected to an ASMi-52. This loopback is used to test all the circuits of the corresponding MSL-8 port, the line to the ASMi-52, and the operation of the ASMi-52.

When this loopback is activated, the selected port sends a remote loopback request to the ASMi-52 connected to that channel. The command is sent through the inband eoc channel, and therefore the inband eoc channel must be enabled for this loopback function to operate.

The loopback is activated within the ASMi-52 user’s interface, which returns the received data through the transmit path.

Figure 4-3 shows the signal paths of a typical remote loopback on the remote ASMi-52.

Megaplex-2100

Other PortInterface

BusInterface

.....Port 8

Port 1

MSL-8

........

RemoteLoopback

ASMi-52

Figure 4-3. Remote Loopback on Remote Unit, Signal Paths

Tests and Loopbacks on Internal Ports

This section describes the tests and loopbacks supported on the internal MSL-8 ports.

The internal MSL-8 ports support the local and remote loopbacks, which can be independently activated for the desired timeslots of any port.



Local Loopback on Selected Port Timeslots

The local loopback on timeslots of a MSL-8 port is used to return the transmit payload carried by selected timeslots of the tested port through the same timeslots of the receive path. The timeslots looped back remain connected to the transmit path of the port, but the corresponding timeslots received from the remote end are disconnected.

This test is recommended for testing signal paths between an I/O port of another module, which needs only a fraction of the available bandwidth, and the MSL-8 port.

The loopback is activated within the MSL-8 routing matrix, and only on the timeslots specified by the user during the activation of the loopback. As a result, there is no disturbance to services provided by the other timeslots of the same port: only the flow of payload carried by the specified timeslots is disrupted.

The signal paths for a local loopback on timeslots for the MSL-8 module are shown in Figure 4-4.

Megaplex-2100

Other PortInterface

BusInterface

.....

Port 8

Port 1

MSL-8

.......

RM

Legend:RM - Routing Matrix

RM

Figure 4-4. Local Loopback on Selected Port Timeslots, Signal Paths

The user can activate the loopback on any individual timeslot, or on several arbitrarily selected timeslots.

When the loopback is activated on timeslots of a port which is part of a redundancy pair, the CL module automatically activates the loopback on the same timeslots of the other port of the pair.

This convenience feature is also available for loopback deactivation: the deactivation command can be issued to either one of the ports of the redundancy pair (even if it has been activated by a command to the other port).



Remote Loopback on Selected Port Timeslots

The remote loopback on timeslots of a MSL-8 port is used to return the receive payload carried by selected timeslots of the tested port through the same timeslots of the transmit path. The corresponding timeslots from the local equipment are disconnected.

This test is recommended for testing signal paths from a remote equipment unit, through the selected timeslots of the MSL-8 port, to an I/O port of another module, which needs only a fraction of the available bandwidth, and the MSL-8 port.

The loopback is activated within the MSL-8 routing matrix, and only on the timeslots specified by the user during the activation of the loopback. As a result, there is no disturbance to services provided by means of the other timeslots of the same port: only the flow of payload carried by the specified timeslots is disrupted.

The signal paths for a local loopback on timeslots for a typical module (MSL-8) are shown in Figure 4-5.

Megaplex-2100

Other PortInterface

BusInterface

.....

Port 8

Port 1

MSL-8CL

.......

RM

Legend:RM - Routing Matrix

RM

Figure 4-5. Remote Loopback on Selected Port Timeslots, Signal Paths

The other features related to loopback activation/deactivation described above for the local loopback on timeslots are also applicable to the remote loopback.


MSL-8 MP-2100/2104 Ver. 12 Technical Support 4-7

4.3 Troubleshooting Instructions

In case a problem occurs, check the displayed alarm messages and refer to the Megaplex-2100/2104 Installation and Operation Manual for their interpretation.

If the problem is detected the first time the module is put into operation, perform the following preliminary checks before proceeding:

• Check for proper module installation and correct cable connections, in accordance with the system installation plan.

• Check the module configuration parameters in accordance with the specific application requirements, as provided by the system administrator.

• If the Megaplex nodal clock is to be locked to the clock recovered from one of the ports of the MSL-8 module, make sure a suitable fallback clock source is configured and provides a good clock signal.

If after collecting all the relevant information, the problem appears to be related to the operation of one of the MSL-8 ports, perform the actions listed below, until the problem is corrected:

• Make sure that no test has been activated on the corresponding MSL-8 port. Use the Megaplex management system to find the active test or loopback and deactivate it.

• Activate the local loopback on the corresponding port. If the indicator of the corresponding local port lights in green while the loop is connected, the problem is external. Check cable connections, and the transmission equipment providing the link to the remote unit.

• You can rapidly check the link to the remote Megaplex unit by activating the remote port loopback at the remote unit. If the link operates OK, the indicator of the corresponding local port lights in green.

If the test fails, there is a problem with the transmission through the network, or with the MSL-8 modules. Repeat the test after carefully checking all the configuration parameters of the module and its ports. If the problem persists, replace the module and check again.

4.4 Technical Support

Technical support for this product can be obtained from the local distributor from whom it was purchased.

For further information, please contact the RAD distributor nearest you or one of RAD's offices worldwide. This information can be found at www.rad.com (offices – About RAD > Worldwide Offices; distributors – Where to Buy > End Users).

Note

http://www.rad.com/


4-8 Technical Support MSL-8 MP-2100/2104 Ver. 12

24 Raoul Wallenberg Street, Tel Aviv 69719, Israel

Tel: +972-3-6458181, Fax +972-3-6483331, +972-3-6498250

E-mail: [email protected], Web site: http://www.rad.com

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