How to load share calls through multiple ISDNs from my CUCM

[carl_townshend]

Hi All

Can anyone tell me how I can load share my calls across both my ISDN 30 circuits in my gateway, at the moment, there is a h323 gateway, I can see 2 dial peers with preferences on them.

The call manager just sends the call to the Gateway.

How would I configure so it can use both? I do not want to run out of channels and I want to use all of them.

cheers

[Nithin Eluvathingal]

Use Trunk Group on GW.

Refer below thread for configuration.

https://community.cisco.com/t5/ip-telephony-and-phones/pri-trunk-group-help/td-p/1130969

[Roger Kallberg]

Either you use a trunk group as @Nithin Eluvathingal suggested or you set the same preference on both dial peers to get IOS to use both of them in a round robin fashion.

[TONY SMITH]

It was a long time ago so this may not apply with current versions.  However last time I used a Trunk Group it had the major disadvantage that voice ports in "down" state were not excluded.  In our case it sequential rather that round robin, but it meant that when the first preference port was down with a line fault, all outbound calls failed until we removed it from the TG (or changed its preference, I can't recall).  This behaviour was verified by TAC because I couldn't believe it was correct operation.

[Scott Leport]

Hi,

In addition to this you can change the distribution algorithm in your CUCM Route Group to circular and it should load share outbound calls which use that particular Route Group. It won't have any influence on your inbound call routing of course, you would need to speak to your carrier about that, but it could allow you some control over how you route your outbound calls via CUCM. 

[Roger Kallberg]

@Scott Leport This is true if you have multiple members of the route group. From the OP my understanding is that there are one H.323 VGW defined in CM that has multiple PRIs and they want to send the calls egress via both of them with no preference between them.