Hi, It sounds like the stateful proxy is not compliant to RFC 6026 concerning 1) should no longer behave statelessly and 2) start using Timer M (defaults 64*T1).
RFC 6026 section 6: "When receiving any SIP response, a transaction-stateful proxy MUST compare the transaction identifier in that response against its existing transaction state machines. The proxy MUST NOT forward the response if there is no matching transaction state machine." RFC 6026 section 8.4: "When a 2xx response is received while in either the "Calling" or "Proceeding" states, the client transaction MUST transition to the "Accepted" state, and Timer M MUST be started with a value of 64*T1. The 2xx response MUST be passed up to the TU. The client transaction MUST NOT generate an ACK to the 2xx response -- its handling is delegated to the TU. A UAC core will send an ACK to the 2xx response using a new transaction. A proxy core will always forward the 2xx response upstream." > -----Original Message----- > From: Alex Balashov [mailto:abalas...@evaristesys.com] > Sent: Sunday, February 16, 2014 8:35 PM > To: sip-implementors@lists.cs.columbia.edu > Subject: [Sip-implementors] INVITE transaction drop by stateful proxy > > Hi, > > I've got a reinvite transaction scenario through a stateful proxy (due > to Record-Route) where the reinvite is not being ACK'd. The proxy > appears to drop state after 7 seconds or less, since, after some > period, > when the retransmissions of the 200 OK back off, the time elapsed > between 200 OKs shows as 7 seconds in my logs, and the second 200 OK is > already showing up as stateless. > > The ACK eventually shows up, but after something like 10 seconds. > > My question is: why is the proxy dropping state for that transaction so > early? As far as I understood RFC 3261 Section 17.2.1 ("INVITE Server > Transactions"), the part that says > > If timer H fires while in the "Completed" state, it implies that > the > ACK was never received. In this case, the server transaction MUST > transition to the "Terminated" state, and MUST indicate to the TU > that a transaction failure has occurred. > > this should be Timer H, which is listed in the table as 64*T1. The > proxy > is using the default T1 value of 500 ms. > > The elapsed time between the origination of the sequential INVITE and > the stateless 200 OK is 7 seconds (any stateful 200 OKs received prior > to this point are not logged). Should it not be ~32 seconds? Or have I > got it all wrong? > > Thanks! > > -- Alex > > -- > Alex Balashov - Principal > Evariste Systems LLC > 235 E Ponce de Leon Ave > Suite 106 > Decatur, GA 30030 > United States > Tel: +1-678-954-0670 > Web: http://www.evaristesys.com/, http://www.alexbalashov.com/ > _______________________________________________ > Sip-implementors mailing list > Sip-implementors@lists.cs.columbia.edu > https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors -- This email is intended solely for the person or entity to which it is addressed and may contain confidential and/or privileged information. If you are not the intended recipient and have received this email in error, please notify BroadSoft, Inc. immediately by replying to this message, and destroy all copies of this message, along with any attachment, prior to reading, distributing or copying it. _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
