SIP register fails with 827-4V (12.3(4)T4)

[bertrand.cordier]

I have an IP Phone 7960 working fine with software SIP and when I look at the register message I have the following:

From: Phone_number@IP_address_Proxy

To: Phone_number@IP_address_Proxy

However, with the 827-4V and IOS 12.3(4)T4, I have a problem registering and the register message looks like that:

From: Phone_number@IP_address_827

To: Phone_number@IP_address_Proxy

Does anyone know why I have IP_address_827 instead of IP_address_Proxy?

Do you think it is related to a bug or if it is a config problem?

[slicker]

Does the register message go through NAT in the 827?

What is the network topology?

Amos

[bertrand.cordier]

The topology is as follows:

POTS TELEPHONE - 8274V - ADSL - 3rd_PARTY_SIP_PROXY

The register message does not go through NAT.