RAD LRS-24 12-Slot Modem Rack with SNMP

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RAD LRS-24 12-Slot Modem Rack with SNMP


  • High density modem rack accommodating any combination of 24 xDSL, fiber or baseband modems

  • Ease of use and low-cost maintenance on PC or UNIX (HPOV) platform through RADview SNMP management

  • Supports ASCII terminal or remote management

  • Supports fiber and copper modems in a single chassis for equipment and operation cost saving

  • A wide range of data rates from 1.2 kbps up to 45 Mbps, for easy and cost effective migration to a higher speed on the same platform

  • A wide variety of modular data interfaces including V.35, X.21, Ethernet and IP router

  • Single or multi IP modes for the rack that includes the modems with built-in SNMP agent (S-Mode cards)

  • Automatic IP addressing configuration (BootP)

  • Supports dial-up modem and dry contacts for major alarms reporting

  • IP fragmentation support

  • Remote software download

  • Storage of up to three software configuration files for a modem and up to two configuration files for the modem rack

  • Remote soft reset of the Central Management (CM-2) and quad modem cards

  • System clock provision

  • Two chassis versions, ANSI and ETSI

  • Optional dual power supply with full redundancy, AC or DC

  • Optional power feeding for remote devices

  • Hot swappable cards


  • LRS - 24 is high-density SNMP managed modem hub. The chassis has 12 slots that accommodate up to 24 modems. Using modular interface cards LRS - 24 can support xDSL, fiber or baseband modems in the same chassis under a single management application (see Table 1).

  • Supports different modem technologies and enables a wide range of data rates starting from 1.2 kbps in IDSL modems through 2 Mbps in HDSL modems, and up to 43 Mbps in fiber modems. These modem technologies enable ranges from 4.8 km at 2 Mbps over copper to 100 km over fiber optic cables.

  • LRS - 24 is available in two different physical hub versions:

    ANSI - card insertion, LEDs and switches are at the front, but cable connections are at the rear of the hub. This compact, 4U high unit complies with the American ANSI standard. Cards can be hot-swapped without removing cables.

ETSI - card insertion, LEDs, switches and cable connections are at the front. This version is 30 cm high (almost 7U), and complies with European ETSI standard. Cards can be hot-swapped without removing cables.

  • All cards can be replaced, or cables removed, during operation, without causing interference to data transmission to/from other cards in the chassis.

  • Modular data interfaces allow modem connectivity using a wide range of data interfaces. These include V.24, V.35, X.21, RS-530, V.36, G.703 Codirectional, E1/T1, built-in Ethernet bridge (with or without VLAN support) and built-in IP router.

  • LRS-24 accepts a system clock via the DB-15 connector placed on the CM-2 card and distributes the clock to all cards.

Management/CM-2 functions

  • LRS-24 is managed by a UNIX?based or PC-based SNMP management system via the Central Management card (CM-2). The software is user-friendly, GUI-based and runs under PC/Windows (RADview-PC) or HP-OpenView (RADview-HP-OV) systems. The SNMP management session can be run over Ethernet (10BaseT or 10Base2 port) or SLIP (RS-232 port).

  • Network management provides centralized control of all LRS-24 hubs, modem cards and remote modems in the network, including interface configuration, connection setup, alarm and monitoring. A single management station can control up to 64,000 LRS-24 hubs.

  • LRS-24 can also be managed from an ASCII terminal. It allows all functions of SNMP except for GUI interface.

  • Telnet support enables terminal connection over any IP network.

  • Performance information is available in graph and table format for the last 24 hours. This information can be saved in a file for accounting purposes.

  • If a major alarm occurs, the LRS-24 CM-2 card can dial out through an external dial-up modem to a central management site. This saves a direct connection to remote sites, while providing alerts if critical events occur. In addition alarms can activate dry contacts. The dry contacts are placed on the system clock connector on CM-2.

  • Two types of modem cards are available on LRS - 24:

    • S-Mode: Cards with built-in SNMP agent. Single IP option is used to reduce the number of addresses used by LRS - 24 and S-mode modems. With this option, only the CM-2 module is assigned an IP address; all connections to the modems are made via CM-2.

    • I-Mode: Cards without SNMP agent. For these cards CM-2 serves as the SNMP proxy agent. The CM-2 built-in agent complies with SNMP MIB II and supports generic SNMP HPOV applications.

  • A new software version can be downloaded from a remote site into the CM-2 via:

    • LAN by TFTP protocol

    • Terminal by X-MODEM protocol

    CM-2 saves up to three software versions.

  • When the management station includes BootP software, the CM-2 card automatically retrieves the IP address required for management connection. This eliminates the need to configure IP addresses for new hub installations.

  • LRS-24 supports IP fragmentation restoring the fragmented IP data sent to the rack by the network management station.

  • Telnet support enables terminal connection over any IP network.

  • LRS-24 performs reset of the remote CM-2 module or CQ modem card via the management software.

  • LRS-24 stores up to three modem configuration files and up to two system configuration files. These files can be copied to any media and used for backup or configuration purposes.

  • The CM-2 panel includes an alphanumeric display with two characters, which alerts on fault conditions during the power-up self-test. During the normal operation it displays the last two digits of the hub number.

Power Supplies

  • LRS-24 operates with single or dual, AC or DC power supplies. Each power supply supports a fully populated LRS-24 hub. Redundant power supply can be replaced during operation, without affecting system performance (hot swapping).

  • Cards of the LRS-24 chassis enable remote power feeding for repeaters and remote standalone modems. For this purpose, a separate power supply, LRS-PS-FEED, should be ordered

Number of Slots

12 card slots

1 slot for the CM-2 module

2 slots for power supply module


Each card has its own connector options (for connector types, see specific data sheet on the card)

Power Supply

AC: 100 to 240 VAC, 47 to 63 Hz, 112W
DC: -48 VDC (-40.5 to -72 VDC)

Management Connection

V.24/RS-232: DB-9, female
Ethernet: RJ-45 or coax (BNC)

System Clock

DB-15 connector

? Physical

ANSI version (B):

Height: 17.7 cm / 7.0 in
Width: 48.2 cm / 19.0 in
Depth: 32.4 cm / 12.8 in

ETSI version (F):

Height: 30.0 cm / 11.8 in
Width: 48.2 cm / 19.0 in
Depth: 25.3 cm / 9.9 in


LRS24/AC48: 8.6 kg / 19.0 lb (one AC and one DC power supply)

LRS24/ACR: 8.1 kg / 17.8 lb (two AC power supplies)
LRS24/48R: 9.0 kg / 19.8 lb (two DC power supplies)

LRS24/AC: 6.9 kg / 15.2 lb (one AC power supply)
LRS24/48: 7.4 kg / 16.3 lb (one DC power supply)

? Environment

Temperature: 0-45C / 32-113F
Humidity: Up to 90%, non-condensing


? LAN Interface


IEEE 802.3 10Base2 (BNC)
IEEE 802.3 10BaseT (UTP)
Connector: shielded RJ-45 or BNC (see Orderin g)

? Terminal Interface

Standard: V.24/RS-232
Rate: 38.4 kbps
Character: Async, 8 bits, 1 stop bit, no parity
Terminals supported: VT-52, VT-100, VT-920
Connector: D-type, 9-pin female

? Indicators

PWR (green): Power ON

TD (yellow): SNMP management transmit data
RD (yellow): SNMP management receive data

Rack indicator:

2-character display for the last two digits of the hub number, or for alerting on system fault condition

? Physical

CM-2 main card:

Height: 158 mm / 6.2 in
Width: 20 mm / 0.8 in
Depth: 235 mm / 9.2 in
Weight: 350g / 12.3 oz

CM-2 interface module:

Height: 103 mm / 4.1 in
Width: 20 mm / 0.8 in
Depth: 93 mm / 3.7 in
Weight 110g / 3.8 oz

? Power


? Environment

Temperature: 0-50  C / 32-122  F
Humidity: Up to 90%, non-condensing






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