Translation Pattern Alternate Routing

s.casper_2 · ‎12-04-2009

On a single Call Manager cluster (6.1.3b) I am looking for a method for alternate routing between sites in the event of a WAN failure. A translation pattern keeps the calls on net. For example:

User at site A dials 914103456029

Translation pattern for the DID range this falls under drops the 9

we use a 11 digit DN so now the call stays on cluster (across the wan to site B) and all is well.

But if the wan is down what do we do with the call? I do not see a way to alternate route a translation pattern to a route group that would send the call out the PSTN.

Our large sites have a subscriber, if the WAn is down, the phones would still be registered CFUR is not an option.

I am not sure AAR would work, my understanding is it provides CAC using Locations to determine the available bandwidth.

Steve

iptuser55 · ‎12-04-2009

This has been asked many times, The issue is that the remote sites are not seen as external and hence normal overflow as in RL will not work. You are correct that AAR only works when the BW is oversubscribed not when the WAN is down. If you want something automatic then that may be hard to do but if you are aware of the WAN going down , then you could reduce the AAR statement to 0 or 1k and that will invoke AAR to overflow to PSTN. Automatically off the top of my head you could hide the remote site DN in a partition called Remote site A then

1. Call from phone 1 to Remote Phone A DN 1234- Partition Remote Site A

2. Phone 1 can only see DN 1234 as a Route Patterns due to a Partition SITE A PSTN

3.The call go to RL with first choice external GW which is configured to re-route the call back to CUCM

4.Call reverts to CUCM which then can see the real Partition of Remote Phone A based upon I/C CSS of the returning GW having Partition Remote Site A

5. If Remote Site A is down then hopefully the RL IN STEP 3 kicks in and 2nd Choice is PSTN

Bascially you are hairpinning the call back from External to Internal- the reason is to have a RL

may work, all smoek and mirrors ???????????

s.casper_2 · ‎12-04-2009

Thanks for the response! Yes I believe that would work but you would think there would be a non smoke and mirror way to do this. Keeping calls on net (or on cluster) is a major selling point of IPT so you would think Cisco would have some alternate routing mechanism in place for when that piece breaks down.....maybe it is commimg in a future release, like you said I am not the first customer to look for this feature.

Steve