SIP Trunking

Unanswered Question
Mar 4th, 2008

Anybody knows how many sip trunks is supporting on a Cisco 3845 with 2e1

I have this problem too.
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Paolo Bevilacqua Tue, 03/04/2008 - 02:31

There is no preset limit.

Since 2 E1 makes 60 calls, if toy send each call to a different destination you will have 60 trunks that is not a big number anyway.

Hope this helps, please rate post if it does!

splata Tue, 03/04/2008 - 03:32

Thanks for your answer

Let me explain better

I have a costumer that needs to E1 to PSTN first, then he needs to conect another E1 service with a carrier for VoIP SIP services. The carrier deliver this SIP trunk with a E1 Interface.

This interfaces will be in a Cisco3825 interconect with a Cisco Call Manager 6.0

The costumer wants 200 IP Phones SIP from Third Part Supplier

Can you tell me if i need a special IOS version in this Gateway?

He ask me. If he needs to add more E1 SIP services from the carrier, How many E1 Services could be receive in this Gateway? It's a physical situation?

Do I need DSPS Upgrade?

Thanks in advance

Paolo Bevilacqua Tue, 03/04/2008 - 03:44


doesn't seem is anything special. You need a minimum of PVDM2-64 in the router, check with "show diag" what do you have.

Note, the idea of using third -party sip phines with ccm is not very good, because the third party ones do not support the features and are not configurable centrally. Depending where you hare, cisco also have cheap sip phones supported by the ccm. And in any case, for just 200 phones, you can supporte them directly on the 3845 itself with CME, no need for CM at all.


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