MGCP-Gateway-Fallback Configuration on the Cisco IOS Gateway ccie training institute in india

Network Bulls
www.networkbulls.com
Best Institute for CCNA CCNP CCSP CCIP CCIE Training in India
M-44, Old Dlf, Sector-14 Gurgaon, Haryana, India
Call: +91-9654672192


To configure the MGCP gateway fallback on a Cisco IOS router to support the MGCP
fallback function, follow these steps:
Step 1 Activate MGCP gateway fallback.
Step 2 Define the service to fall back to.
To enable outbound calls while in SRST mode on an MGCP gateway, you must configure
two fallback commands 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 Software releases before 12.3(14)T, configuring MGCP gateway fallback involves
the ccm-manager fallback-mgcp and call application alternate commands. With Cisco
IOS Software releases after 12.3(14)T, configuring MGCP gateway fallback uses the
ccm-manager fallback-mgcp and service commands.
NOTE Both commands have to be configured. Configurations will not work reliably if
only the ccm-manager fallback-mgcp command is configured.
To use SRST on an MGCP gateway, you must configure SRST and MGCP gateway
fallback on the same gateway.
Example 6-4 Cisco Unified SRST Configuration Example
IRemoteSite#configure terminal
RemoteSite(config)#call-manager-fallback
RemoteSite(config-cm-fallback)#ip source-address 172.47.2.1 port 2000
RemoteSite(config-cm-fallback)#max-ephones 3 dual-line
RemoteSite(config-cm-fallback)#max-dn 6
RemoteSite(config-cm-fallback)#limit-dn 7960 2
RemoteSite(config-cm-fallback)#keepalive 20
RemoteSite(config-cm-fallback)#end
RemoteSite#
MGCP-Gateway-Fallback Configuration on the Cisco IOS Gateway 131
MGCP Fallback Activation Commands
The Cisco IOS command ccm-manager fallback-mgcp, shown in Example 6-5, enables
the gateway fallback feature and allows an MGCP voice gateway to provide call-processing
services through SRST or other configured applications when CUCM is unavailable.
Example 6-5 MGCP Fallback Activation Commands
RemoteSite#configure terminal
RemoteSite(config)#ccm-manager fallback-mgcp
RemoteSite(config) # c a l l application alternate Default
RemoteSite(config-app-global)#service alternate Default
The call application alternate Default command specifies that the default voice application
takes over if the MGCP call agent is unavailable. This allows a fallback to H.323 or
SIP, which means that local dial peers are considered for call routing.
The service alternate Default command is entered in the global-configuration submode of
the application-configuration submode. To navigate to this location, follow these steps:
Step 1 To enter application configuration mode to configure applications, use
the application command in global configuration mode.
Step 2 To enter application-configuration global mode, use the global command
in application configuration mode.
Enter either of the two commands, depending on the Cisco IOS Software release. The
newer configuration method is the service command.
As discussed in the preceding chapter, analog calls are preserved in the event of MGCP
fallback. To provide call preservation during switchback, call preservation for H.323 has to
be enabled using the commands shown in Example 6-6.
Example 6-6 H.323 Call Preservation Activation Commands
RemoteSite#configure terminal
RemoteSite(config)#voice service voip
RemoteSite(conf-voi-serv)#h323
RemoteSite(conf-serv-h323)#no h225 timeout keepalive
MGCP Fallback Configuration Example
Figure 6-5 shows an MGCP-controlled remote-site gateway with an MGCP-gatewayfallback
configuration for an SRST-enabled Cisco IOS router, as shown in Example 6-7.
132 Chapter 6: Implementing Cisco Unified SRST and MGCP Fallback
Figure 6-5 MGCP Fallback Example
Main Site
Example 6-7 MGCP Fallback Configuration Example
RemoteSite#configure terminal
RemoteSite(config)#ccm-manager fallback-mgcp
RemoteSite(config)#application
RemoteSite(config-app)#global
RemoteSite(config-app-global)#service alternate Default
RemoteSite(config-app- global)#end
RemoteSite#
NOTE More commands might be necessary, depending on the complexity of the
deployment.