On 24 Nov 2008, at 15:55, Jeremy Jackson wrote:
On Mon, 2008-11-24 at 15:20 +0000, cayle.spandon@gmail.com wrote:
I'm not sure if this is the right mailing list for this question: how widely is TRIP (Telephone Routing over IP [RFC3219]) deployed / used in current networks? http://xconnect.net/ is the big ENUM provider, I think that's the method that has gained popularity for VoIP Peering on the signaling end. TRIP sounds like it would be useful for finding QoS routes for media streams.
Hi, Jeremy, Cayle, All -- I am regularly involved with SIP interconnect. There are a number of providers of similar Federated/All-call-query-ENUM Multilateral Islands, but they do not befit the bilateral interconnect model which most people involved with voice interconnect need to follow, so that they can manage quality and the commercial properties of individual prefixes. *Some* of the island methods I have seen, perform signaling arbitration and media transcoding so that all parties on the island can communicate with all other parties, which is worrying to me as one of the benefits of end-to-end VoIP is the preservation of wideband audio codecs and new signaling features across the call path, compared with lowest-common-denominator call routing (just like TDM paths in the middle). I discussed this with Richard Shockey last year and proposed to him an out-of-band, trip-like gateway protocol that could express prefixes along with all relevant technical and commercial properties between telecoms peers. If the commercial and technical properties fit the requirements of the peer, then the prefix is appended to the dialplan of the peer (be it via a local ENUM zone or some other prefix/call routing method). The point is that the protocol to communicate prefixes and attributes needs to be call routing agnostic. I did some work on this protocol, but don't feel ready to take the document to the relevant working groups at this stage, but would welcome feedback on it from anyone here who is involved with voice interconnect. This is a bit layer 7ish, so the thread is possibly reaching a conclusion on list, but I really hope it continues off-list. best wishes Andy