This document presents the Telephony Routing over IP (TRIP). TRIP is a policy driven inter-administrative domain protocol for advertising the reachability of telephony destinations between location servers, and for advertising attributes of the routes to those destinations.
 
TRIP's operation is independent of any signaling protocol, hence TRIP can serve as the telephony routing protocol for any signaling protocol.

The Border Gateway Protocol (BGP-4) is used to distribute routing information between administrative domains. TRIP is used to distribute telephony routing information between telephony administrative domains. The similarity between the two protocols is obvious, and hence TRIP is modeled after BGP-4.

There is an open-source TRIP protocol stack as part of the Vovida VoIP suite of tools but it has not seen any work since 1.0.0 which was released in 2001. It currently does not compile on latest Linux 9.0 systems. It can be found on http://www.vovida.org/protocols/downloads/trip/

Both Acme Packet and Jasomi have TRIP-capable session controllers, though at this time not enough data is known about them to comment thoroughly. Additionally, these are hardware-based systems which have significant costs associated with their implementation.