Unity and SRST mode

Unanswered Question
Sep 11th, 2008


would it be possible to have Unity voicemail messaging in branch site working while in SRST mode ?

I have found documentation about unity with CME-as-SRST, but we have a "pure" SRST GW (due to max phone support: 240 for CME as SRST, 720 with SRST).


Aside, I have found documentation for generic voice mail integration with SRST:


Would this latter work with a Unity System ?



I have this problem too.
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Jaime Valencia Thu, 09/11/2008 - 06:38

the ports need to register to work, that's why the solution for this is the CME-AS-SRST.

a "pure" SRST assumes the communication has been lost and calls will be routed thru PSTN but at main site CUCM is up and running along with Unity and they're both communicating fine (ports are registered)

pure SRST won't register the unity ports, if you want this then you'll need to use CME-as-SRST



if this helps, please rate

m.schlienger Thu, 09/11/2008 - 06:43

Actually the Unity server would be located on branch site as described in the cisco document

Integrating Cisco Unity with Cisco Unified CME-as-SRST

So Unity will not be communicating with CUCM when in SRST mode, as described in the document. So what would make the registration to a "pure" srst gateway impossible, while it would be on a "CME-as-SRST" ?

Thanks for your help


Jaime Valencia Thu, 09/11/2008 - 06:47

i'm aware of that. not the 1st time i've seen the scenario. that's why i explained that scenario of why this would not work pure SRST.

SRST registers phones, not VM

CME can register VM ports

that's why the option is CME-as-SRST and not pure SRST



if this helps, please rate


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