Adding the MGCP gateway to CUCM
The signaling interface is fully configured
The voice port is ready:
Troubleshooting Domain Name Unreachable error
I tried to register my MGCP gateway to my CUCM, but every time I did a “show ccm-manager”, it displays the following:
I first thought about an issue about DNS on CUCM. I remembered that, during the CUCM installation, I put CUCM somewhere.
So I went to every corner of CUCM admin pages, where I could find the “CUCM” keyword.
I changed some settings in Enterprise Parameters. I even tried to change the hostname under the CUCM CLI mode:
Then, I examined what’s happening at the router level, with “debug mgcp events”. I noticed this line:
I figured that the gateway could not solve the hostname “CUCM”. I found out that one quick solution was to set up a DNS server on the router, that resolves “CUCM” into “18.104.22.168”.
Here’s a good document that explains the concept.
I did a “no ccm-manager config”, then “ccm-manager config”.
I still don’t know why the gateway IP address shows “unknown” on CUCM :p
Configure a fractional T1 PRI on MGCP gateway
By default, when we configure a MGCP gateway on CUCM, all PRI timeslots are activated.
CUCM does not support fractional T1 PRI on MGCP gateways. But with a combination of the configuration server feature and manual tweaking, we can reduce the number of timeslots used.
In this example we will reduce the number of used data/voice timeslots from 23 to 6.
First we shut down the T1 controller
Then we shut down the signaling interface:
We shut down the voice port
We disable PRI backhauling under the signaling interface
We change the number of PRI timeslots under the T1 controller:
We disable the TFTP server configuration
We remove the configuration server feature
We enable PRI backhauling under the signaling interface
We reset MGCP process
And we verify that the number of data/voice timeslots has been reduced to 6:
Implement route patterns, route lists, route groups and digit manipulation with MGCP gateways
The concept of route patterns, route lists and route groups in the context of MGCP gateways does not differ from other types of gateways. However, in regards to digit manipulation, it is done at the CUCM level and not the IOS level. That’s because a MGCP gateway is a “dumb” slave that executes the order of the MGCP call agent.