[OpenSIPStack] OpenSBC with FOKUS openIMS

[Gaurav K. <gk...@ve...>]

Hi

I am trying to use OpenSBC with FOKUS OpenIMS. I have following 2 queries:

Query1:
I am using the following setup:

UE-----P-CSCF-----OpenSBC-----I/CSCF----S/CSCF

UE: 10.0.64.11:3422
OpenSBC: 10.0.64.17:7060

P-CSCF is configured to forward all messages to OpenSBC. OpenSBC is
configured to forward all messages coming from UE to I-CSCF. The outbound
proxy in UE is set as P-CSCF.

When UE sends the REGISTER, Contact header contains 10.0.64.11:3422. OpenSBC
changes it to 10.0.64.17:1544 (one more address on which OpenSBC is
listening) before forwarding to I-CSCF.

In the response from S-CSCF to I-CSCF, contact address is 10.0.64.17:1544.
In this response message when OpenSBC forwards to P-CSCF, contact address
still remains 10.0.64.17:1544. OpenSBC doesn't translate it back to
10.0.64.11:3422. As P-CSCF gets 10.0.64.17:1544 in Contact header in
response from S-CSCF, it updates the UE Contact address in its tables from
10.0.64.11:3422 to 10.0.64.17:1544 as part of registration process.

UE is registered now with contact 10.0.64.17:1544 at P-CSCF and S-CSCF.

Now when UE initiates INVITE message, the contact address in the message is
10.0.64.11:3422. But in P-CSCF's table, the contact address for the same UE
is 10.0.64.17:1544. Due to this mismatch, P-CSCF discards the message saying
that User should first register with S-CSCF.

The issue is that OpenSBC is not re-translating the contact address (to what
UE sent in the request) in the REGISTER response which it sends to UE.

Has anyone used OpenSBC with FOKUS OpenIMS? Can anyone point out the =20
issue here?

Query2:
UE-----P-CSCF-----I/CSCF----S/CSCF-----OpenSBC------OtherDomain
Here how to configure OpenSBC to remove P-Asserted-Identity from the =20
INVITE message before it forwards the message to OtherDomain when call =20
comes in with the Privacy header.

Regards,
Gaurav Kansal