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New Member

Convert MGCP Gateway to H.323

I am using Cisco 2811 routers as voicegateways with FXO ports to the local PSTN for my remote sites with CallManager 4.3(1). Now, in order to be able to get the CallerID in, I must change my remote voice gateways to from MGCP to H.323.

Does anyone have a good example of the gateway H.323 configuration including the SRST configuration needed?

I have been researching and find bits and pieces but would like to get an example of it all in one place. Then I can do the work in my test environment to verify and refine.



Re: Convert MGCP Gateway to H.323


here is a collection of pieces for H323 on CCM and FXO sides:

CCM side:

H.323 Dial Plan:

FXO Configuration:

now the dial plan is ready even for SRST, u just want to add some commands to activate srst, i would recommend u to walk with the comprehensive guide: SRST Admin Guide, but basically here are the srst commands u need:


please remember to rate helpful posts


New Member

Re: Convert MGCP Gateway to H.323


Which model number FXO do you have? I have VIC-FXO, which does not support caller ID. VIC2-FXO does. Verify before moving to H.323.


New Member

Re: Convert MGCP Gateway to H.323

this is a real basic H323 config with SRST

Current configuration:

version 12.1

voice class h323 1

h225 timeout tcp establish 3

!--- Set the timeout to three seconds.

dial-peer voice 100 voip

preference 1

!--- Make this the first choice dial peer.

ip precedence 5

destination-pattern 1...

voice-class h323 1

!--- Apply the voice class to the dial peer.

session target ipv4:

!--- This is the address of the primary Cisco CallManager.

dtmf-relay h245-alpha

dial-peer voice 101 voip

preference 2

!--- This is the second choice.

ip precedence 5

destination-pattern 1...

session target ipv4:

!--- This is the address of the secondary Cisco CallManager.

dtmf-relay h245-alpha



!--- Enables SRST support and enters Cisco CallManager fallback mode.

max-conferences 8

ip source-address port 2000

!--- is the IP address of the Cisco IOS gateway through which it

!--- communicates with the Cisco IP Phones.

!--- Here, the Cisco IOS gateway is also configured as a Cisco CallManager fallback server.

max-ephones 10

max-dn 10