Cisco Unified SCCP and SIP SRST Feature Overview
MGCP Gateways and SRST
23
Cisco Unified SCCP and SIP SRST System Administrator Guide
OL-13143-04
MGCP Gateways and SRST
MGCP fallback is a different feature than SRST and, when configured as an individual feature, can be
used by a PSTN gateway. To use SRST as your fallback mode on an MGCP gateway, SRST and MGCP
fallback must both be configured on the same gateway. MGCP and SRST have had the capability to be
configured on the same gateway since Cisco IOS Release 12.2(11)T.
To make outbound calls while in SRST mode on your MGCP gateway, two fallback commands must be
configured on the MGCP gateway. These two commands allow SRST to assume control over the voice
port and over call processing on the MGCP gateway. With Cisco IOS earlier than 12.3(14)T, the two
commands are the
ccm-manager fallback-mgcp
and
call application alternate
commands. With
Cisco IOS releases after 12.3(14)T, the
ccm-manager fallback-mgcp
and
service
commands must be
configured. A complete configuration for these commands is shown in the section the
“Enabling Cisco
Unified SRST on an MGCP Gateway” section on page 64
.
Note
The commands listed above are ineffective unless both commands are configured. For instance, your
configuration will not work if you only configure the
ccm-manager fallback-mgcp
command.
For more information on the fallback methods for MGCP gateways, see the
Configuring MGCP Gateway
Support for Cisco Unified Communications Manager
document or the
MGCP Gateway Fallback
Transition to Default H.323 Session Application
document.
Support for Cisco Unified IP Phones and Platforms
The following sections provide information about Cisco Feature Navigator and the histories of
Cisco Unified IP Phone, platform, and Cisco Unified CM support from Cisco SRST Version 1.0 to the
present version of Cisco Unified SRST.
•
Finding Cisco IOS Software Releases That Support Cisco Unified SRST, page 23
•
Cisco Unified IP Phone Support, page 24
•
Platform and Memory Support, page 24
•
Cisco Unified Communications Manager Compatibility, page 24
•
Signal Support, page 25
•
Language Support, page 25
•
Switch Support, page 25
Finding Cisco IOS Software Releases That Support Cisco Unified SRST
Note
With Cisco IOS Release 12.4(15)T, the number of SIP phones supported on each platform is now
equivalent to the number of SCCP phones supported. For example, 3845 now supports 720 phones
regardless of whether these are SIP or SCCP.
To access Cisco Feature Navigator, go to
http://www.cisco.com/go/cfn
. An account on Cisco.com is not
required.