The communication channel is not established

I am trying to solve this problem for the last two weeks without any luck.

I have an Asterisk 1.4 running under Fedora 6.

This is what happends:

  1. I have four SIP lines with two different providers.

  2. I have two lines with VOIP2LINK. These are DID from Canada. They work without problems. I am using GSM codec.

  3. I have two lines with INPHONEX. One line works but the other it doesn’t want to work. They are sharing the same configuration but still I can’t understand why one is working and the other one not.

More details with the problem

I phoned INPHONEX and with the excuse that they don’t support Asterisk configuration they couldn’t help me.

I can see in my configuration that the registration is working properly. Also, I tried changing the codecs but it didn’t work.

What happends is that when the caller calls, the analog phone I have attached to the DIGIUM CARD rings. When I answer the phone I heared nothing. However, on the caller side nothing changed. For the caller, the receiver never answered the phone.

I checked the SIP protocol. I followed the sequence and I ddin’t notice anything different between the two lines I have. The sequence is the same.

There are only two difference at the package level:

  1. Althougt I bougth the two lines from the same provider, the SIP messages are comming for two different servers.

  2. In the from ‘sip:xxxx@IP’ in one case the xxx is a telephone number and in the other case (the one that doesn’t work) says ‘unkownd’.

I appreciate any comment or suggestions that might help me to solve the problem.