Route calls to PSTN when WAN link is down

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Nov 22nd, 2007
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I've got an Intercluster Trunk (non-gatekeeper controlled) between a 6.0 and a 4.1 cluster. I implemented AAR as well. First question: is it enough, to specify the AAR Group only on the Intercluster Trunk or will I have to specify it on each Phone? Second question: How is it possible to reroute a call to PSTN, when the WAN Link is down(I know, that this does not work with AAR)?



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Jon Nelson Sat, 11/24/2007 - 16:19
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You will have to specify the AAR group on each phone (line and device) and you will also have to create an AAR CSS for each phone and apply it. The AAR CSS should be applied to the ICT as well.

I would refer to the CUCM Admin Guide for both versions you are using for detailed setup.


Thank you,

Jon Nelson

gogasca Sat, 11/24/2007 - 18:46
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AAR is only when no bandwidth is available using CCM CAC (Locations)

when WAN is down, use CF Unregistered, not ava in 4.1 but in 4.2.

For this scenario i recommend u use RouteList selecting ICT at first, then PSTN GW prefixing digits.

pwenger Sun, 11/25/2007 - 22:40
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I tought also to do it with a RouteList. But for any reason I can't choose the ICT in the RouteGroup. Do you have any idea why?

Remember, there is a Interclustertrunk over the WAN, so when the WAN goes down, the phones are still registered and so CF Unregistered makes no sence.



gogasca Sun, 11/25/2007 - 23:39
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Its because its already assigned to a Route Pattern.

Yes, for your scenario CFU is not valid

iptuser55 Fri, 01/04/2008 - 04:06
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I was informed this solution may work

Extension 1111, partition "remotesite" is on a remote site SRST site with a full DID 1546785xxxx

Create a translation pattern of 1XXX and assign a new partition "TP1XXX" to the TP. You then assign a CSS to extension 1111 which contains both "remoteste" and "TP1XXX" partitions but the "remotesite" is higher order- in the event that the remote extension is not available due to WAN being down , the call to 1111 will choose the TP1XXX partition as the first choice partition , "remotesite" is no longer available. The TP 1xxx will then translate the internal number 1111 to the full DID. Reading another design doc I understand this can work in 3.x but does it not in 4.x - will it work in 5.X bearing in mind the "not registered call forward setting"

mciarfello Wed, 09/17/2008 - 18:45
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IPTUSer, I couldn't get that to work. remotesite_pt doesn't go away and the call fails trying to dial the 1111 in remotesite_pt. If I change the order of the calling device's CSS so TP1XXX_PT is first and dial 1111 the call goes through, but that's not an automatic failover.

The dialplan analyzer lists the TP as an alternate match, but it's not routing to that alternate match.

Do you have more information?



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