Steve Underwood wrote: > 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.
Yes, I was going to mention SS7... does opbx support that yet? I vaguely remember seeing some rumblings about it a while back. Anyway, running SIP ~or~ H.323 over an IP network is sometimes the only option (unless you want to use FXO cards and POTS), since some exchanges don't have ISDN, either at all, or have simply run out of linecards.... which is the reason why my local telco sometimes use Alcatel 5020 softswitches and run voip trunks out to CPE (albeit converted to E1 at CPE, and you can't touch the voip trunk). Don't get me wrong, I'm still going to be forced to use PSTN of some kind (mainly BRI) for many customers. It's mature technology, much more mature than anything in the voip world. But (going back a few emails in the thread), the point I was trying to make is that once you have an external box handling your PSTN, with H.323/SIP trunk to your PBX, it's very easy to migrate away from PSTN in future, and run your H.323/SIP trunk over some kind of WAN. It also potentially liberates you from having to run a PC... ie, you can use embedded devices that you couldn't plug a PCI card into. Why do businesses pay for a high speed internet feed, which can easily have QoS implemented on it in the case of "corporate" WAN options (as opposed to consumer ADSL), then pay for multiple BRI or channelised E1/T1? _______________________________________________ Openpbx-dev mailing list [email protected] http://lists.openpbx.org/mailman/listinfo/openpbx-dev
