On Fri, Aug 15, 2008 at 11:56:30PM -0500, Tilghman Lesher wrote: > > There's no hairpin involved: the point of TBCT is that you tie up *0* > > timeslots instead of 2, to forward a call. > > There is a hairpin involved. The call (for several milliseconds at least) is > using two channels on the PRI before the 2BCT succeeds, and then the call > no longer takes up any channels. It is only when the PRI detects the hairpin, > through the native bridge code that it is able to detect that the call is > eligible for 2BCT.
I'll assume you've watched it on a PRI, so I'll defer, but I wouldn't expect that myself; I would expect that when you tell the switch to transfer it, you go immediately from one B channel to 0. > > Why would an Asterisk instance call itself on the same span? > > Very simple. Call your main number, and if you don't have special logic > in your internal dialplan context to handle that, the call will go out to the > telco and dutifully come right back in on the same circuit. Sure, but that's not a target for TBCT anyway. > > > Similarly, Asterisk cannot complete a 2BCT request, if Asterisk is on the > > > NET side of the PRI circuit. That might could be added in the future, > > > but it is not supported now. > > > > > > So in summary, Asterisk can request 2BCT, but it cannot perform a 2BCT if > > > requested from the other side. > > > > Nothing can perform a TBCT unless it's a PRI server, not a client; it's > > function of 5ESS's and DMSen; you have to be an SS7 speaker to do it in > > the first case. > > I don't think that's the case. Matt would know more, and his reply suggests > that it certainly would be possible for Asterisk to do this. SS7 is not at > all required here. Allow me to phrase it differently: TBCT is a feature of LEC/IXC edge switches; there isn't much use for it in any other context. I don't care if you're using Asterisk to be an edge switch, but it's a *carrier* feature, by and large. Certainly in the specific instance I'm discussing, it is. Cheers, -- jra -- Jay R. Ashworth Baylink [EMAIL PROTECTED] Designer The Things I Think RFC 2100 Ashworth & Associates http://baylink.pitas.com '87 e24 St Petersburg FL USA http://photo.imageinc.us +1 727 647 1274 Those who cast the vote decide nothing. Those who count the vote decide everything. -- (Josef Stalin) _______________________________________________ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- AstriCon 2008 - September 22 - 25 Phoenix, Arizona Register Now: http://www.astricon.net asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
