Cisco MGX 8880 Media Gateways

Cisco Voice Interworking Switch Service Module

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The Cisco® Voice Interworking Service Module (VISM-PR) is a packet voice module for the Cisco MGX® 8880 Media Gateway and Cisco MGX 8000 Series Multiservice Switches. The Cisco VISM-PR offers robust packet voice functions for service providers and enterprise customers.

Product Overview

The Cisco VISM-PR (Figure 1) offers a field-proven full set of voice-over-IP (VoIP) and voice-over-ATM (VoATM) features, including toll-quality voice, fax, and modem. The Cisco VISM-PR can be deployed in standalone configurations or with softswitches to enable a variety of packet voice services in network architectures using the Media Gateway Control Protocol (MGCP), PacketCable™ Trunking Gateway Control Protocol (TGCP), H.323, and Session Initiation Protocol (SIP). Operators can use the advanced features of the Cisco VISM-PR to rapidly deploy revenue-generating packet voice networks.
The Cisco VISM-PR provides full investment protection for existing Cisco MGX 8000 Series Multiservice Switch customers by providing the ability to add revenue-generating packet voice services to existing multiservice networks.
The Cisco VISM-PR is field proven with deployments in more than 30 countries worldwide and in more than 100 service provider and enterprise networks, providing a range of applications and services.

Figure 1. Cisco VISM-PR (Front Card)


Features and Benefits

Tables 1 through 5 provide information about the Cisco VISM-PR.

Table 1. Features and Benefits of Cisco VISM-PR



8T1/E1 interfaces per module

• Cost-effective entry and scalability

Time-division multiplexing (TDM) interfaces

• Direct termination of 8 T1 or 8 E1 interfaces
• T3, OC-3, or STM-1 interface connectivity using optional Service Resource Module (SRM)

Packet technology

• VoIP and VoATM (ATM Adaptation for AAL1 and AAL2)
• Support for standalone and softswitch-based applications

High availability

• Cisco MGX platform support for 1:1 common equipment redundancy and 1:N Cisco VISM-PR redundancy

Deployment flexibility

• Proven successful deployments with Cisco and partner softswitches worldwide
• VoIP and VoATM support with the same hardware and software

Table 2. Overview of Cisco VISM-PR Protocols and Features



Call control


Signaling interfaces

• Channel Associated Signaling (CAS), Feature Group D (FG-D) support for E911 and operator services, Signaling System 7 (SS7) and Inter-Machine Trunk (IMT), and ISDN Primary Rate Interface (PRI)

Voice compression

• G.711, G.723.1, G.726, G.729a/b, Clear Channel

Digital-signal-processor (DSP) features

• G.165, G.168-2000 integrated, nonblocking echo cancellation; programmable up to 128 ms
• Transparent transcoding between a-law and µ-law encoding
• Voice activated detection, silence suppression, and comfort noise generation
• Fixed and adaptive jitter buffering
• Preprogrammed and configurable support for tone detection and generation
• Dual Tone Multi Frequency (DTMF) relay for IP and ATM
• DTMF relay to softswitch
• CAS signal translation and manipulation
• Continuity test support
• Bit Error Rate Test (BERT) and loopback test (with optional SRM)

Modem and fax

• T.38 Fax Relay (gateway or softswitch controlled)
• Fax and modem passthrough


• Real-Time Transport Protocol (RTP) and RTP Control Protocol (RTCP) (RFC 1889)
• DTMF Relay (RFC 2833)
• Resource Reservation Protocol (RSVP) and Call Admission Control (CAC)


• Standards-based AAL2 Adaptation and subcell multiplexing
• Support for Constant Bit Rate (CBR), Real-Time Variable Bit Rate (VBR-rt), and Non-Real-Time VBR (VBR-nrt) ATM traffic classes


• Onboard announcement storage and playout

Lawful intercept

• Lawful intercept (Communications Assistance for Law Enforcement Act [CALEA]) support for call content

Management interfaces

• Simple Network Management Protocol (SNMP)
• Command-line interface (CLI)
• Telnet
• Secure Shell (SSH) protocol

Table 3. Product Specifications for Cisco VISM-PR



Chassis compatibility

• Cisco MGX 8880 Media Gateway
• Cisco MGX 8850 Multiservice Switches
• Cisco MGX 8830 Multiservice Switches

Physical specifications

Front Card

• Height: 7.25 in. (184.1 mm)
• Depth: 16.14 in. (409.9 mm)
• Weight: 3.0 lb (1.4 kg)

Back Card

• Height: 7 in. (177.8 mm)
• Depth: 4.125 in. (104.7 mm)
• Weight: 0.6 lb (0.29 kg)


• Operating temperature: 32° to 104°F (0° to 40°C)
• Operating (noncondensing): 10 to 85 percent

Power consumption

67W per module



• UL 1950 3rd Ed./CSA C22.2 No. 950 (covers United States and Canada)
• IEC 60950 (covers EU for CE marking)


• 47 CFR Part 15: 2002
• CISPR22: 1997
• EN55022: 1998
• EN61000-3-2: 2000
• EN61000-3-3: 1995
• EN300386: 2001
• VCCI: V-3/2000.04
• EN300386: 2001
• EN50082-1: 1997
• EN61000-6-1: 2001 Central Office Equipment [USA]
• GR1089: Issue 2: Rev1: 1999
• GR1089: Issue 3: October 2002


• TIA-968-A 2002 (USA)
• CS-03 Issue 8 1996 (Canada)


• RTTE Directive (1999/5/EC) 1999 (CE)

Telcordia CLEI

• GR-485-CORE - CLEI coding
• GR-383-CORE - CLEI code label
• GR-209-CORE - PCN Process

Table 4. TDM Interfaces for Cisco VISM-PR




Port speed

1.544 Mbps

2.048 Mbps

Number of interfaces



Port media

100-ohm twisted pair

120-ohm twisted pair

Port connector


RJ-48 or SMB

Line coding

Binary 8-Zero Substitution (B8ZS) or Alternate Mark Inversion (AMI)

High Density Bipolar Order 3 Encoding or AMI

Line framing

ANSI T1.408 Extended Superframe format line framing and clear channel

ITU-T G.704 16 frame multiframe line framing and clear channel

Table 5. Availability and Ordering Information for Cisco VISM-PR

Product Description

Part Number


Front Card

Back Card

Cisco VISM-PR with 8 T1 interfaces


AX-RJ48-8T1, AX-R-RJ48-8T1

Cisco VISM-PR with 8 E1 interfaces


AX-RJ48-8E1, AX-R-RJ48-8E1

For More Information

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