Daniel Swarbrick wrote: >bkml wrote: > > >>SIP is not my idea of a unified call model either and it won't be for >>a variety of reasons. >> >>There is a proven standard already out there, it's called Q.931 and >>that should be the yardstick. >> >> > >You're lucky if all your installations are within reach of ISDN. Some of >mine aren't, and the availability of IP-based WAN options nearly always >exceeds ISDN availability - whether that be frame-relay, leased line, >xDSL, wireless, laser... voice is pretty easy to move, once it's in an >IP packet. And voip is the reason why most of us are interested in this >project, is it not? > > I think you miss the point. The ISDN call model, embodied in Q.931, is a superset of all the other call models. Any form of telephony today will fit into the ISDN (which is also the SS7) call model. No other call model can say that. H.323 is Q.931 based. SIP is just a hacked up abortion, but it is nowadays trying hard to be like ISDN. MGCP is a misconception designed to support a twisted gateway/switch model within a ISDN based world.
>Of course, if you prefer to use TDM protocols, there is a project that >was originally designed to do just that, and still suffers from a fairly >TDM-centric design... ;-) > >Sure, SIP has its problems, and different implementations of it have >different problems at that... but it's rapidly becoming the de facto >standard for voip. The mere fact that Cisco Call Manager v5 seems to >give at least equal importance to SIP as it does to their own SCCP, >speaks volumes. > >Heck, even some telcos are starting to use IP WANs with a voip to E1 >converter at the CPE, going into legacy PBXs, and thus eliminating the >need for adding more PRI linecards in their exchanges. It's probably >only a matter of time before they simply offer a SIP trunk and be done >with it. > > Regards, Steve _______________________________________________ Openpbx-dev mailing list [email protected] http://lists.openpbx.org/mailman/listinfo/openpbx-dev
