[OpenSIPStack] OpenSBC SIP multipart behaviour

[Craig G. <cra...@gm...>]

Hi,

 

I am currently doing interop testing with Level3 who are a tier 1 VoIP
provider in the USA.  The architecture I am using has a single box running
OpenSBC listening on port 5060 and a copy of Callweaver running on port
10060 behind OpenSBC.  OpenSBC is running in B2BUA mode with upper
registration and is handling both SIP and RTP.

 

I have found during interop testing that OpenSBC is not preserving the SDP
when initiating the second leg of the call to Callweaver, causing Callweaver
to reject the call with '488 - Not Acceptable Here'.

 

The difference between the Level3 SIP and other SIP that I've seen is that
Level3 are including multiple parts in the message body.  If I take OpenSBC
out of the equation and have Level3 talk directly to my Callweaver then
there is no problem.

 

I have included two tcpdumps of a session.  The first dump, wanside.cap is
the session from Level3 to OpenSBC and the second dump (lanside.cap) is the
session between OpenSBC and Callweaver.  I am happy to capture and provide
OpenSBC log and debug if required.

 

I'd be interested to know if this is a bug, or otherwise.

 

Craig