SIP>PRI Route Group

[Brian Carscadden]

Communications Manager 7.x/8.x w/ SIP and PRI trunks. Client wants to prioritize SIP over PRI. From an outage and capacity standpoint are there any caveats in setting this up?

Also, from a capacity standpoint I assume I need CAC to allow it to correctly overflow from the SIP to the PRI, correct?

Any info appreciated.

Brian

[Felipe Garrido]

Does the SIP trunk terminate directly to the SIP SP or does it terminate on an IOS gateway which then forwards to the SIP SP? The overflow/capacity will depend on how the SIP SP handles the situation, whether it returns an error or doesn't respond at all. Location based CAC would be the best method to control it on CUCM, if there is no IOS gateway involved.

-Felipe

[Brian Carscadden]

Felipe, thanks for the quick reply.

The SIP trunk is being terminated on a local ISR.

Also, SIP trunk encompasses 3 T1s. If 1 or 2 of the T1s is down how do I handle the changes in CAC?

Thanks,

Brian

[Felipe Garrido]

Do you mean to say that the the traffic to the SIP SP goes over 3 data T1s? If the connection to the SIP SP goes down, IOS will return an abnormal disconnect cause to the CUCM which will then route the call to the next member of the route list/group.

-Felipe

[Brian Carscadden]

What I'm asking is that if 1 or 2 of the 3 total T1s go down, how will UCM handle this?

Since the three T1s determine the overall capacity of the SIP trunk, and we configure CAC with a set budget for this bandwidth - how would UCM know that the link can not support a certain capacity?   And would it use the next member of the RG or RL?

[Felipe Garrido · Accepted solution]

Brian,

CUCM would not be aware of that type of failure. It would continue to assume that the full amount of bandwidth, configured under the location, is available.Someone would need to manually make a change.

-Felipe

[Brian Carscadden]

Thanks for the help!

[Abu Hadee]

Hi

Since the SIP trunk is terminated on local ISR, it is working as CUBE.

In that case you can use Embedded event manager(EEM) to do some action and take care of T1 downs.

Let me give you some example..

lets say you configure 3 dial-peer with priority and max-conn. So gw will control number of calls you can have.

Now you can configure some script on IOS for EEM so if lets say 1st T1 goes down, dial-peer 1 will be shutdown. So CUBE will operate only with 2 dial-peer and have appropriate number of calls. If more call comes in to CUBE that it can not handle with 2 T1, then it will send "no circuit available" to cucm and CUCM will route to different path. In that case, your SIP Trunk and PRI will need to be in two different Route group within a Route list.

Hope this helps.

Thanks

- abu