Call Forward Hops limitation

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Sep 24th, 2009
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I've the following scenario: 2 CCM clusters connected via an Intercluster Trunk not GK controlled.

One Cluster is versione 3.3 and the other 7.1.

For IP extensions migration reason I need to have a RP XXXX pointing from one cluster to the other, because extensions still on the old cluster needs to be able to call extensions on the newer one. BUT this create calls loop IF an IP phone registered on the old cluster calls an unregistered ip phone. The call started to bounce from the old cluster to the new (where unregistered phone are forwarded to the old cluster) and this is the problem.

I was looking for a way to limit this scenario; I tried block offnet to offnet calls but it doesn't work. Do you have any suggestions (maybe limiting the maximum forwarding hops?)?


Best Regards


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Jaime Valencia Thu, 09/24/2009 - 07:51
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The hop counter does not help here because each call that comes and goes has different ID. Only if you were doing the calls within phones in the same cluster it would work.

You need to modify the CSS on one of the clusters so they cannot reach them if unregistered to avoid the loops.

Block Offnet to offnet is for transfers, not for CF



if this helps, please rate

r-marchetti Fri, 09/25/2009 - 00:24
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ok this helps for the unregistered phones, thanks.

But I still have the problem if a phone on the old cluster calls a not existing extension in the IP Phones numbering plan. In this case it matches the XXXX RP, goes to the newer CUCM (where the extension doesn't exist), matches the XXXX RP, then went back to old CCM and so on.


Best Regards



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