TRIP deployment?

Andy Davidson andy at
Tue Nov 25 08:21:33 UTC 2008

On 24 Nov 2008, at 15:55, Jeremy Jackson wrote:

> On Mon, 2008-11-24 at 15:20 +0000, cayle.spandon at 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?
> 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

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