I do not recommend attempting to use OPTIONS to determine call/dialog state.
RFC 3261 is ambiguous concerning if a 481 should ever be sent for OPTIONS. Similarly RFC 5057 clarifies that OPTIONS is not part of dialog usage; thus a 481 has no impact/meaning. There isn't another OPTIONS response to clearly indicate that the related dialog is unknown/terminated (and destroy the entire dialog). RFC 3261 section 11.2: "An OPTIONS request received within a dialog generates a 200 (OK) response that is identical to one constructed outside a dialog and does not have any impact on the dialog." RFC 3261 section 12.2.2: "Requests that do not change in any way the state of a dialog may be received within a dialog (for example, an OPTIONS request). They are processed as if they had been received outside the dialog." RFC 5057 section "OPTIONS does not belong to any usage. Only those failures discussed in Section 5.1 and Section 5.2 that destroy entire dialogs will have any effect on the usages sharing the dialog with a failed OPTIONS request." > -----Original Message----- > From: Tarun2 Gupta [mailto:tarun2.gu...@aricent.com] > Sent: Wednesday, June 26, 2013 5:33 AM > To: ikuzar RABE; sip-implementors@lists.cs.columbia.edu > Subject: Re: [Sip-implementors] SIP messages exchange to maintain a > session > > Hi > > For keep alive, you can use OPTIONS or Session Timers (see RFC 4028) > for details on usage. > > Regards > Tarun Gupta > Aricent > > > -----Original Message----- > From: ikuzar RABE [mailto:ikuzar9...@gmail.com] > Sent: Wednesday, June 26, 2013 2:57 PM > To: sip-implementors@lists.cs.columbia.edu > Subject: [Sip-implementors] SIP messages exchange to maintain a session > > Hi all, > > I'd like to know if there are SIP messages exchange to maintain the > session between two UA (message such as "Hello, I'am still here" / > "Hello, I'am still here too" while RTP conversation is established and > lasts a longtime. > > The context: > I have to differentiate an INVITE with a BYE which arrives one hour > after an INVITE (so a conversation that lasts one hour) and an INVITE > with no BYE ... (packet lost or another problem ...) _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
