On Mon, Nov 7, 2011 at 7:28 PM, Ari Sonesh <[email protected]> wrote: > > Content-Type: text/plain; > charset="utf-8" > Content-Transfer-Encoding: 8bit > Organization: SipXecs Forum > In-Reply-To: <[email protected]> > X-FUDforum: 08063afcdd00a6e76393c5b9527381e8 <64373> > Message-ID: <[email protected]> > > > > I believe that the issue is inherent to mobile data networks > that are buffering initial (after standby) data traffic > until it can allocate a channel to transmit the data to a > receiver. Once channel is allocated the traffic is flowing > well. > > This initial buffering creates an issue with SipX which is > using lower than standard timeout between an Invite and a > corresponding Ack. What happens is that the Sipx sends > Invite and there is no response (as it's still buffered by > the mobile network), so after 100msec it sends another > invite, and another after 200msec, and yet another after > invite after 400msec, and then after a timeout it gives up. > Now, once a channel becomes available all 4 invites are > immediately sent and acknowledged by the remote endpoint, > but by then SIPx already gave up, but the called extension > is ringing. > > When the channel is allocated fast the call setup and the > conversation are flawless. > > This behavior (initial buffering)is characteristically for > all mobile networks. > > We really need to find a solution to this issue through A) > work around B) design change. > > It's acceptable for the caller to wait for some time > (probably as much as 10 seconds) before there is a "ring" > response from the called side.
I probably would not agree with 10 seconds... > > Any suggestions for a work around? I think it is important to understand first whether the trunk provider or gateway uses a precall service before jumping to this conclusion. At the same time, the question is a good one, "how long should the system wait before retrying". _______________________________________________ sipx-users mailing list [email protected] List Archive: http://list.sipfoundry.org/archive/sipx-users/
