Cisco Systems MGX 8230 manual Vism Redundancy, Card Combinations

Chapter 2 Module and Service Descriptions

Frame Relay Service Modules

MGCP 0.1 for VoIP with Softswitch Control

VISM supports Media Gateway Control Protocol (MGCP) Version 0.1. This open protocol allows any Softswitch to interwork with the VISM module.

Resource Coordination via SRCP

Simple Resource Control Protocol (SRCP) provides a heartbeat mechanism between the VISM and the Softswitch. In addition, SRCP also provides the Softswitch with gateway auditing capabilities.

Full COT Functions

VISM provides the capability to initiate continuity test as well as provide loopbacks to facilitate continuity tests when originated from the far-end.

Courtesy Down

This feature provides a mechanism for graceful upgrades. By enabling this feature, no new calls are allowed on the VISM while not disrupting the existing calls. Eventually, when there are no more active calls, the card is ready for a upgrade and/or service interruption.

PRI Backhaul to the Softswitch Using RUDP

The PRI backhaul capability provides PRI termination on the VISM with the Softswitch providing call control. ISDN Layer 2 is terminated on the VISM and the layer 3 messages are transported to the Softswitch using RUDP.

Latency Reduction (<60 ms round-trip)

Significant improvements have been made to bring the round-trip delay to less than 60 ms.

Codecs Preference

VISM provides the capability to have the codecs negotiated between the two end-points of the call. The VISM can be configured, for a given end-point, to have a prioritized list of codecs. Codec negotiation could be directly between the end-points or could be controlled by a Softswitch

31 DS0 for E1 with 240 Channels Only

While all 31 DS0s on a E1 port can be used, there is a limitation of 240 channels per card.

VISM Redundancy

The VISM redundancy strategy is the same as for any of the eight port cards in the MGX 8230.

•For VISM-8T1, 1:N redundancy is supported using the SRM-3T3.

•For VISM-8E1, 1:N redundancy is supported only via LMs using the SRM-3T3 or the SRM-T1E1.

Card Combinations

A card set has an VISM-8T1 or VISM-8E1 front card and one of the following back cards:

•AX-RJ48-8T1-LM

•AX-R-RJ48-8T1-LM (for redundancy support)

•AX-RJ48-8E1-LM

•AX-SMB-8E1-LM

•AX-R-SMB-8E1-LM (for redundancy support)

	Cisco MGX 8230 Edge Concentrator Installation and Configuration
Release 1.1.31, Part Number 78-11215-03 Rev. B0, May 2001		2-57