Hi Gaurav, I dont understand why proxy will generate 181 response when this is an end-to-end response? Then what and how proxy will fill as a To-Tag in 181?
thanks Ritesh On 12/21/06, Gaurav Kheterpal <[EMAIL PROTECTED]> wrote: > > GK>> One of the uses of 181 is the scenario of 'Call Forwarding no No > Answer'. > > The proxy sends back a 181 response to the caller to indicate that the > original call is being forwarded to a new destination (URI) & subsequently > sends an INVITE to the new callee. > > The difference between 181 and 3xx level forwarding is that 181 indicates > proxy level forwarding while 3xx response is mostly used in UA level > forwarding. > > Refer the call flow at http://www.tech-invite.com/Ti-sip-service-9.html. > > And rfc 3261 also says all provisional > messages except 100 trying must have "To" tag in the section 8.2.6.2. > > GK>> The 'To' tag is of relevance in case of forking as there might be > multiple responses returned by UAS. The 'To' tag helps a UAC distinguish > between these final responses. > > I hope this helps. > > Regards, > Gaurav > > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Ritesh > Tiwari > Sent: Thursday, December 21, 2006 1:43 AM > To: [email protected] > Subject: [Sip-implementors] Use of 181--Call is being forwarded > > Hi, > > I don't understand the use of SIP response 181 "Call is being forwarded". > 181 is a end-to-end response. And rfc 3261 also says all provisional > messages except 100 trying must have "To" tag in the section 8.2.6.2. > > thanks > _______________________________________________ > Sip-implementors mailing list > [email protected] > https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors > > _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
