Sending a CANCEL before a provisional response is invalid behavior. Right now, the stack forges a CANCEL/200 and sends it to the TU, but does not allow the CANCEL to hit the wire. From here, if B never sends a provisional, the INVITE transaction will time-out, causing the stack to send a simulated INVITE/408. However, if B does respond, the call will continue normally. (This is something a TU must be prepared to handle; just because you get a CANCEL/200 doesn't mean the remote UAS will end the INVITE transaction.) If B does send a provisional, but never sends a final response, it is up to A to decide at what point it wishes to end the transaction. (The TU does this by sending a CANCEL; this will cause the stack to put a CANCEL on the wire, and start a timer that will cause the INVITE transaction to be torn down, if it never gets a response)
Best regards, Byron Campen
…
From: resiprocate-devel-bounces@xxxxxxxxxxxxxxxxxxxx [mailto:resiprocate-devel-bounces@xxxxxxxxxxxxxxxxxxxx] On Behalf Of Volodymyr.Stepanov@xxxxxxxxxxx
Sent: Friday, May 04, 2007 7:57 AM
To: resiprocate-devel@xxxxxxxxxxxxxxxxxxxx
Subject: [reSIProcate] CANCEL before provisional recieved.
Hello!
Currently i'm investigating SIP using resiprocate library.
And i'm stuck at such problem.
User A send INVITE to User B.
After that A sends CANCEL and , like RFC sais i've no effect ,so call remains established on the User B side.
[Scott] It is unclear exactly what is happening here. Did B send a 200 response? If B receives a CANCEL before sending a 200 then the call should be cleared.
What is the way to "fix" this problem?
Currently if A try to send CANCEL in trying state I send BYE...Am I doing right?
[Scott] Not too sure what you are describing. It is legal to send a BYE after receiving a 18x response from an endpoint – this should cause this leg of the call to be ended only – but the INVITE transaction is still active, other potential forks can still respond. If you really want to terminate the entire call before receiving a 200, you should send a CANCEL. Note: I’ve seen some endpoints have trouble receiving a BYE in the trying state. The RFC is pretty clear on what is required on both sides for a CANCEL.
I found couple of thougths about this problem in resiprocate-devel mailing list ,but there os no specifically decision.
Deeply appreciate for attention.
//******************************************************************************************************/
Ok :)
Try to explain my problem.
Main issue is when user A tries to send CANCEL just after INVITE, so no answers from B side recieved .
In logs I have lines .
DEBUG | 20070504-161143.776 | PortalAgent | RESIP:TRANSPORT | 1644 | Transport.cxx:258 | incoming from: [ V4 10.15.3.7:5060 UDP target domain=unspecified received on: Transport: [ V4 10.15.8.37:5080 UDP target domain=unspecified connectionId=0 ] on 10.15.8.37 connectionId=0 ]
WARNING | 20070504-161143.776 | PortalAgent | RESIP:TRANSACTION | 1644 | TransactionState.cxx:423 | You can't CANCEL a request until a provisional has been received
DEBUG | 20070504-161143.776 | PortalAgent | RESIP | 1644 | Helper.cxx:302 | Helper::makeResponse(SipReq: CANCEL admin/unittest3@xxxxxxxxx tid=f179f93ee801be35 cseq=CANCEL / 1 from(tu) code=200 reason=
DEBUG | 20070504-161143.776 | PortalAgent | RESIP:TRANSACTION | 1644 | TransactionState.cxx:1721 | Send to TU: TU: DialogUsageManager size=0 SIP/2.0 200 OK
On A side call hanged, but B remains in the dark about this fact
I understand ,that stack works like said in RFC, but what should I do to prevent wrong call state on the B side?
Thanks for patience :)
Best regards,
Volodymyr Stepanov
A R I C E N T
Kyiv, Ukraine
MSN : stepanov_v_m@xxxxxxxxxxx
ICQ : 272708933_______________________________________________
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