CUCM, SRST & Unity Connection

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Nov 6th, 2009
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We have a scenario, where SRST Router and Unity Connection are in one site, which connects to CUCM in other site.

In case the WAN link fails, how will the Unity Connection work with the SRST? How will the Unity Connections ports register with SRST?

Is there any configuration which can be performed to use Unity Connection during the WAN failure for the IP Phones registered with the SRST router?


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Overall Rating: 4.5 (2 ratings)
Jaime Valencia Fri, 11/06/2009 - 19:35
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Since both Unity and CUC integrate with SCCP you should be able to use CME-as-SRST using the Unity method to integrate during WAN outage with the local CUC



if this helps, please rate

csshenoy80 Fri, 11/06/2009 - 21:08
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The Unity Connection and SRST Router are at one site and Cisco Call Manager is another site. If WAN goes down, the IP Phones would regsiter with the local SRST, but how would the Unity Connection work? Would local users in SRST site be able to use the UNity Connection?

p.holley Tue, 11/10/2009 - 13:25
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Looking for the same solution. I have SRST and Unity at remote site and CUCM 7.X at central site. Would like to use SRST with Unity when the WAN goes down.

Any ideas?


p.holley Thu, 11/12/2009 - 06:25
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Thanks, I found some good doc on how to do it. One issue I am facing right now is at the remote site I have a translation rule that translated the DIDs to 4 digit numbers, then the voip dial peer send the call to CUCM at the central site and the phone rings.

When I introduce CME config at the remote site, while the phone say ext 4000 is still registered with CUCM at HQ (WAN is up). If i call the DID of ext 4000, it matches the ephone-dn for that extension instead of the voip dial peer to CUCM. Consequently, the caller get Unity Message and the extension does not ring.

How do i work around this. tried higher preference on the ephone-dn, but no luck. I guess closest digits match first before wild card 4...

Any ideas

Md. Mijanur Rahman Tue, 11/10/2009 - 23:25
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Was facing the same problem and was searching for the solution eagerly, cause there is no guideline at the admin guide or any technote at site. Thanks Jamesha!


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