Yup. I am sure you mustb e going thru RFC 3261. On Fri, Oct 8, 2010 at 2:43 PM, Santosh Kal <[email protected]> wrote:
> > Thanks for detailed explanation. > > Following is what I have understood: > > 1. Via header gives the details of the nodes (IP, port etc) a given Initial > request has travelled through and on UAS used to identify the nodes the > response should be travelling through. > 2. Record header is build based on record-route (which every proxy adds in > the Initial request) and used for future request/responses. > > Is this the correct understanding? > > Thanks, > Santosh K > > > From: "$...@r\\/|>r!`/@" <[email protected]> To: > Santosh Kal <[email protected]> > Cc: > [email protected] > Date: 10/08/2010 09:10 AM Subject: Re: [Sip-implementors] Via or Route > header to send response to the requestor at Proxy > ------------------------------ > > > > Hi Santosh, > > The responses are always send as per VIA only. When the initial request as > in which can establish a dialogue is coming from UAC to UAS via a proxy, > during the traversal, each hop's IPaddress is appended in the VIA header > field. The hop's are can be determined by pre existing route set and DNS > lookups. Say > > UAC------->P1-------->P2--------->P3---------->UAS. In this example say P1 > and P2 were part of pre configured route set and P3 as part of DNS lookups. > All UAC, P1, P2, P3 will be in the marked in VIA field. > Also there is a concept of Record Route as well. SIP entities which are > part of initial routing of the message can mark themselves in Record route > which means they will receive all further requests and their responses for > that particular dialog/session. You can read in detail about this. > > Coming back to the scenario, now when UAS sends back the response to the > request, The response will go through P3, P2, P1 and finally UAC(pls notice > the order). The VIA header reuses the effort of routing the initial request > to the UAS and thus ensures that all those elements which were part of the > initial request also know about the response. > > UAC<------P1<------P2<-------P3<-------------UAS. > > The if suppose the dialog is established b/w UAC and UAS and for all > further requests and its responses, the route field will be used to route > the call. Route is calculted by the Record Route header field. > > For more details, refer RFC 3261 for this. > > On Thu, Oct 7, 2010 at 10:16 PM, Santosh Kal > <*[email protected]*<[email protected]>> > wrote: > Hello All, > > To send response back to initiator proxy uses Route header and Via > header. > > Could you please help me understand which field is used in which scenario. > > Thanks, > Santosh > =====-----=====-----===== > Notice: The information contained in this e-mail > message and/or attachments to it may contain > confidential or privileged information. If you are > not the intended recipient, any dissemination, use, > review, distribution, printing or copying of the > information contained in this e-mail message > and/or attachments to it are strictly prohibited. If > you have received this communication in error, > please notify us by reply e-mail or telephone and > immediately and permanently delete the message > and any attachments. Thank you > > > _______________________________________________ > Sip-implementors mailing list* > **[email protected]*<[email protected]> > * > **https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors*<https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors> > > > > -- > cheers!!!! > sarvpriya > *http://sarvpriyak.blogspot.com/* <http://sarvpriyak.blogspot.com/> > > > =====-----=====-----===== > Notice: The information contained in this e-mail > message and/or attachments to it may contain > confidential or privileged information. If you are > not the intended recipient, any dissemination, use, > review, distribution, printing or copying of the > information contained in this e-mail message > and/or attachments to it are strictly prohibited. If > you have received this communication in error, > please notify us by reply e-mail or telephone and > immediately and permanently delete the message > and any attachments. Thank you > > > -- cheers!!!! sarvpriya http://sarvpriyak.blogspot.com/ _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
