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Cisco 3925 as a ISDN2SIP Gateway


We have a Cisco 3925 configured with CME 7 and enabled with the UC module. The machine also has a PRI and some BRI cards.

Is the following possible; a ISDN call comes in the Cisco 3925 (does not hit CME yet), the call is routed to our SIP platform, the SIP platform routes the call back to Cisco 3925 and a phone configured in CME should start ringing.

Is this possible?

I know it sounds odd to do this, but there are internal reasons why the call needs to travel through the SIP platform and back to the Cisco.

Thanks in advance!



2 Replies 2

Hi Grant.

A way to achieve this is to send the incoming call with the DDI to the SIP platform, than translate it to the internal extension and route the call back to the VG.







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Hello Carlo,

That sounds good! 

I have the following configuration for the VG and CME:

dial-peer voice 2000 pots
 description Incoming ISDN
 incoming called-number .T
 port 0/3/0:15

 dialplan-pattern 1 7657270.. extension-length 4 extension-pattern 10..

ephone-dn  62  octo-line
 number 1054
 label Grant
 name Grant

Whenever someone (external) dials 765727054 my extension starts to ring. 

From what I remember, an incoming call from ISDN always matches this dial-peer 2000 first, then it goes matching for "virtual" (not sure what these are called) dial-peer which I did not manually create.

Something like:

List of Matched Outgoing Dial-peer(s):
  1: Dial-peer Tag=20157

After this my extension/phone rings.

So, I need to change this dial-peer 2000 to send the call to the SIP platform? How do I do that? The session target command does not work, since the dial-peer is marked as pots and not voip.


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