Hi In my opinion OPTIONS should be used for querying the capability of the peer user agent and not as keep alive mechanism. For established dialog (specifically two-party call) session timer is one option for checking that UAS is alive or not.
There are two more keep-alive techniques mentioned in section 3.5 of below draft which can be used. For TCP (ping-pong mechanism) and for UDP keep alive with STUN. Path - http://tools.ietf.org/html/draft-ietf-sip-outbound-20 Two answer your second question it is not necessary to send OPTIONS from a registered user. regards Abhishek Dhammawat Aricent -----Original Message----- From: sip-implementors-boun...@lists.cs.columbia.edu [mailto:sip-implementors-boun...@lists.cs.columbia.edu] On Behalf Of Manoj Priyankara [TG] Sent: Thursday, August 06, 2009 6:40 PM To: sip-implementors@lists.cs.columbia.edu Subject: [Sip-implementors] SIP OPTIONS Dear All, According to the RFC 3261, SIP OPRIONS message should be used to query the statue of other UAC or the UAS. Is it OK to use the OPTIONS as a keep alive message to know whether the UAS is alive? Is it necessary to send the OPTIONS message from a registered user or is it possible to send the OPTIONS message from a general user and get 200- OK as the response? Thanks BR, Manoj _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors "DISCLAIMER: This message is proprietary to Aricent 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. Aricent 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 Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
