Nitin, PUBLISH with soft-state has a life time associated with it. If Server detects that there is expiration of this duration, it can assume the user is off-line. The problem is that the Server needs to wait for the publish expiration to conclude. The server may like to decrease the refresh rate to avoid long publish life-time. Other way is use some device audit technique like using OPTIONS, the server can pole the availability of the PUA.
You may like to couple registration with presence but again the registration has the same problem as PUBLISH as the client will not be able to un-register if it is not turned-off gracefully and this technique assumed that the registrar and presence-server are somehow able to communicate. http://www.veraznetworks.com ~Vikram On Mon, Apr 7, 2008 at 11:14 AM, Nitin Arora <[EMAIL PROTECTED]> wrote: > Hi, > > I am working on a presence client and using SER as presence server. > I am using PUBLISH to publish my presence status (i.e. online, offline, away > etc.) to the sever, and using SUBSCRIBE, NOTIFY to know the status of the > UAs in my friend's list. > > Now my problem is what if my UA is turned off and unable to send PUBLISH to > update its presence status. is there any way to get rid of this problem. > > one way I can think of is that Server will check for the registration status > of that UA and on registration expiration it will automatically change the > presence status to offline, but what if registration period is too long, its > presence status will be kept like orphan on the proxy. > > second way is that UA itself periodically update the status through PUBLISH > but I don't know if any IETF standard defines or recommends this and if such > rfc exists then Does SER (Proxy) supports it or not? > > Please share any opinion. > > Thanks & Regards > Nitin Arora > _______________________________________________ > 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
