NATTING SIP phone lines

Unanswered Question
Jun 9th, 2010
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anyone knows if there is a configuration of a Cisco Router with voice functionalities to act as a SIP phone?

A customer's scenario is the following:
- the customer has no.5 SIP phone
- each phone has its own number registered to an external SIP provider
- external SIP provider can't establish a trunk SIP with customer router that is a Cisco 2821 with voice functionalities

I am wondering if a Cisco 2821 router could do the following:
- register IP phones on router (with SIP or SCCP)

- register SIP lines provided by the external VoIP provider directly from router
- route the calls from ip phones to SIP PBX of my provider through Cisco 2821 based on some policies defined on the router without configuring a SIP Trunk.

In this way the router behaves, in the VoIP world, similarly when running NAT for IP address.

Is it possible?

thx in advance


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paolo bevilacqua Thu, 06/10/2010 - 00:24
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Yes, a router (CME) can do all these things, with some limitations.

However, you need a reputable consultant or cerfied cisco partner to configure these, otherwise nothing will ever work.


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