Hi,
in r1821 you can find my first shot at this scenario, a b2bua which
enables SST on both sides, and does the SDP ping pong as below.
I am sure that there are many cases which are not handled properly,
for example, if we have started one INVITE ping-pong from the B2B,
then we should not accept re-INVITE from the ends, but refuse them
with 491; atm I think the re-INVITE would just get relayed and two
INVITE transactions would be running simultaneously.
Another issue is what to do when re-INVITE fails, I think that this is
not handled properly at the moment (it is just ignored, but should
probably tear down both calls - that's the thing for, I guess).
A third todo is to pass the headers through. Possibly, this should be
implemented with a header filter or the like.
Regards
Stefan
Klaus Darilion wrote:
Yes, it is complex if the B2BUA does not have a media relay ( in which
case providing the SDP (at least the port information) itself).
Am 22.04.2010 16:01, schrieb Stefan Sayer:
or, other possibility, empty reinvite:
A b2b B
|---INVITE / SDPa-->| |
| |---INVITE / SDPa-->|
| | |
| |<-- OK/SDPb--------|
| |--- ACK ---------->|
|<-- OK/SDPb--------| |
|--- ACK ---------->| |
| | |
... sst timer expires ...
| | |
|<--INVITE | |
| | |
|--- OK/SDPc------->| |
now what? ignore that, or do
| |---INVITE / SDPc-->|
| |<-- OK/SDPd--------|
This is the proper approach.
one more ping-pong?
No.
|<----ACK/SDPd------|----ACK----------->|
No more ping-pongs needed.
regards
klaus
--
Stefan Sayer
VoIP Services Consulting and Development
Warschauer Str. 24
10243 Berlin
tel:+491621366449
sip:sa...@iptel.org
email/xmpp:stefan.sa...@gmail.com
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