It is my understanding that the Expires: header will define an expiry value for the transaction, whereas an expires= parameter will define an expiry value for a particular AOR<->Contact binding.
Note that a particular Address Of Record may have multiple active Contacts associated with it -- each unique device that REGISTERs for a user will have a separate Contact binding. Each of these Contacts may have a unique TTL. Older SIP UAs will send an Expires: header in their REGISTER request, although this is somewhat uncommon now. Most newer SIP UAs will omit the Expires: header and send a Contact with an expires= parameter. And this is the preferred method. ---------- Original Message ---------------------------------- From: [EMAIL PROTECTED] Date: Fri, 23 Jul 2004 11:00:06 +0530 > > > > >please find my answers inlined... > > > > Sarika Gupta > <[EMAIL PROTECTED] > om> To > Sent by: [EMAIL PROTECTED] > sip-implementors- cc > [EMAIL PROTECTED] > ia.edu Subject > [Sip-implementors] Expires Header > Vs Expires Paramter in Contact > 07/22/04 07:49 PM > > > > > > > > > >Hi >I have a query on the precedence between Expires >header and Expires in Contact in 200 OK message > >As per the text in RFC3261, REGISTER message can >contain Expires in either the Expires header or the >Expires parameter in Contact header. And as per my >understanding if both are present then the value in >Expires parameter of Contact header overrides value in >Expires header. Is this correct? > >SHETTI>> Yes, above I'd consider as the correct behavior. > >In 200 OK sent in response to a REGISTER, I have two >issues >1. Since RFC 3261 clearly says that the Contact in 200 >OK Must Contain Expires Parameter, this implies that >if the Contact is present, its Expires parameter >should be filled. Now my question does it mean that if >a Contact is present Expires header shall be absent in >200 OK? > >SHETTI>> 'Expires' header has not been given any significance >in the RFC for responses to REGISTERs. Even if it is >present, it needs to be ignored as the contact "MUST" >contain the 'expires' parameter and expires parameter >is preferred over expires header. > >2. If not then who takes the precendence expiry value >in Expires header or Expires pameter in Contact >header? > >SHETTI>> I think expires param always has priority over >the expires header in general. > >Thanks > > > > > > >___________________________________________________________ALL-NEW Yahoo! >Messenger - sooooo many all-new ways to express yourself >http://uk.messenger.yahoo.com >_______________________________________________ >Sip-implementors mailing list >[EMAIL PROTECTED] >http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors > > >"DISCLAIMER: This message is proprietary to Hughes Software Systems Limited >(HSS) and is intended solely for the use of the individual to whom it is >addressed. It may contain privileged or confidential information and >should not be circulated or used for any purpose other than for what it is >intended. If you have received this message in error, please notify the >originator immediately. If you are not the intended recipient, you are >notified that you are strictly prohibited from using, copying, altering, or >disclosing the contents of this message. HSS accepts no responsibility for >loss or damage arising from the use of the information transmitted by this >email including damage from virus." > >_______________________________________________ >Sip-implementors mailing list >[EMAIL PROTECTED] >http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors > ______________ ______________ ______________ ______________ Sent via the KillerWebMail system at acmepacket.com _______________________________________________ Sip-implementors mailing list [EMAIL PROTECTED] http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
