Hi, let me redefine a question I already did:
- A client initiates a SIP UDP call with a server. The call is
correctly established.
- After the INVITE transaction the client sends an in-dialog OPTIONS
to check the dialog status.
- Due to a SIP stack bug, the server ignores the in-dialog OPTIONS (no
response is given but the dialog and RTP remains active in both
directions).
- The client retransmits the OPTIONS until a transaction timeout
occurs (32 seconds). At this point the client decides to stop sending
RTP but doesn's send a BYE.
- The call remains active in the server until a RTP timeout occurs
(i.e. after 1 minute without receiving RTP from the client). Then the
server sends a BYE and receives 481 because the client closed,
internally, the call.
- Client's CDR shows a call of 32 seconds (until the OPTIONS
transaction failed due to timeout).
- The server's CDR shows a call of 92 seconds (the initial 32 plus 60
seconds until RTP timeout raises).
Server side argument: The client should send a BYE after it detects
the in-dialog OPTIONS timeout by following RFC 3261 section 12.2.1.2
(the BYE is mandatory):
---------------------------------------
If the response for a request within a dialog is a 481
(Call/Transaction Does Not Exist) or a 408 (Request Timeout), the UAC
SHOULD terminate the dialog. A UAC SHOULD also terminate a dialog if
no response at all is received for the request (the client
transaction would inform the TU about the timeout.)
For INVITE initiated dialogs, terminating the dialog consists of
sending a BYE.
---------------------------------------
Client side argument: A failing OPTIONS means that the server is
unreachable so it doesn't make sense to send a BYE (taken such
argument from RFC 3261 section 11):
---------------------------------------
As is the case for general UA behavior, the transaction layer can
return a timeout error if the OPTIONS yields no response. This may
indicate that the target is unreachable and hence unavailable.
---------------------------------------
I'm pretty sure that section 12.2.1.2 (server side argument) has
preference over section 11, this is, an in-dialog failed transaction
(due to timeout) must force the client sending a BYE to terminate the
call. Such BYE could arrive to the server or not (in case there are
network problems or the server is down), but it must try to send such
BYE.
However I would like to hear your opinnions about this issue, along
with any other reference justifying one of both arguments.
Thanks a lot and best regards.
--
Iñaki Baz Castillo
<[email protected]>
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