Configure the Cisco Unified CallManager Express router for H.323 Interworking with Cisco Unified CallManager

Say if you have a CUCM running in HQ and CUCME running in branches, do you know how to link it up together? Here is an example in configuring H.323 networking between the CUCME and CUCM.

Configure a codec preference list

voice class codec 1
codec preference 1 g711ulaw
codec preference 2 g711alaw
codec preference 3 g729r8

Configure a H.323 voice class

voice class h323 1
h225 timeout tcp establish 3 ! TCP connection establishment timeout

Configure a H.323 dial peer between CUCME router and CUCM cluster

dial-peer voice 1000 voip
description VOIP to CUCM
destination pattern ^10..$
session target ipv4:192.168.1.1 ! CUCM IP address
voice-class codec 1 ! Assign Voice Codec Class to dial peer
voice-class h323 1 ! Assign H.323 voice class to dial peer
preference 1 ! This is required when multiple servers are avail in the cluster

When WAN is down, re-route the calls to CUCM over PSTN

dial-peer voice 1001 pots
description VOIP route PSTN to CUCM
destination-pattern ^10..$
preference 9 ! Lower preference than VOIP dial peer
port 0/0/1:23
prefix 1408555 ! Modify the 4 digit destination to 11 digits for PSTN access

To Verify:

show dial-peer voice summary
show dialplan number
show call active voice
show call active voice brief
show isdn status

On interface configuration, add the h323-gateway voip bind srcaddr

interface GigabitEthernet0/0.194

encapsulation dot1Q 194

ip address 192.168.3.2 255.255.255.0

h323-gateway voip interface

h323-gateway voip bind srcaddr 192.168.3.2

On CUCM, create a H.323 gateway with the IP address 192.168.3.2. Reset the gateway and try to establish the call from CUCME to CUCM