Hi Markus, For the flow in discussion, proxy is stateful and it has a IST and an associated ICT. For a non-successful final response for INVITE, ACK is generated/consumed by the transaction not the TU. Hence I said, proxy(TU) cannot associate the ACK for 480 with ACK for 487.
Regards, Ramakrishna -----Original Message----- From: Markus Hofmann [mailto:[EMAIL PROTECTED] Sent: Friday, May 05, 2006 11:40 AM To: Ramakrishna Adukuri (WT01 - IP-Multimedia Carrier & Ent Networks) Cc: [email protected] Subject: Re: [Sip-implementors] question on the behavior of 487 message. Hi Ramakrishna, [EMAIL PROTECTED] wrote: >> It can do either. >> > Isn't this statement violating Invite Client Transaction. As per the ICT state machine it is the responsibility of *INVITE client transaction* to generate an ACK on receipt of 300-699 response. I don't think proxy(TU) can tie the ACK for 480 with ACK for 487. > If an ACK will be received the proxy must check (branch-id of the via header) if a server INVITE transaction exist, if yes the ACK was for the proxy. The call flow INVITE, 300 - 699, ACK has the same branch-id (for example z9hG4bK776asdhds) and is one transaction. If the proxy has no information about a server INVITE transaction the ACK was not for the proxy and it must be forwarded. The call flow INVITE, 2xx, ACK has two transactions. INVITE and 2xx are one transaction (for example z9hG4bK987abdes) and the ACK is an own transaction (z9hG4bK-4345). Regards, Markus > -Ramakrishna > > -----Original Message----- > From: [EMAIL PROTECTED] on behalf of Dale R. > Worley > Sent: Thu 5/4/2006 11:03 PM > To: Sip-Implementors > Subject: Re: [Sip-implementors] question on the behavior of 487 message. > > On Thu, 2006-05-04 at 09:15 -0700, Siddhardha Garige wrote: > >> In this case should proxy wait unitl it gets ACK for 480 and then >> send an ACK to 487 ? Or should it consider 480 and 487 as seperate events? >> > > It can do either. > > Dale > > --- > interop.pingtel.com -- the public SIP phone interoperability test > server > > _______________________________________________ > Sip-implementors mailing list > [email protected] > https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors > > > > > The information contained in this electronic message and any attachments to this message are intended for the exclusive use of the addressee(s) and may contain proprietary, confidential or privileged information. If you are not the intended recipient, you should not disseminate, distribute or copy this e-mail. Please notify the sender immediately and destroy all copies of this message and any attachments. > > WARNING: Computer viruses can be transmitted via email. The recipient should check this email and any attachments for the presence of viruses. The company accepts no liability for any damage caused by any virus transmitted by this email. > > www.wipro.com > _______________________________________________ > Sip-implementors mailing list > [email protected] > https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors > The information contained in this electronic message and any attachments to this message are intended for the exclusive use of the addressee(s) and may contain proprietary, confidential or privileged information. If you are not the intended recipient, you should not disseminate, distribute or copy this e-mail. Please notify the sender immediately and destroy all copies of this message and any attachments. WARNING: Computer viruses can be transmitted via email. The recipient should check this email and any attachments for the presence of viruses. The company accepts no liability for any damage caused by any virus transmitted by this email. www.wipro.com _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
