SS8 puts TRIP protocol in SignalingSwitch

SS8 Networks began testing a beta version of its SignalingSwitch IP-based signaling transfer point (STP) this week using a dynamic routing protocol under development with the Internet Engineering Task Force (IETF.)

The Telephony Routing over Internet Protocol (TRIP) runs in SS8’s IP telephony routing engine and will be used to route PSTN calls over IP networks, particularly across multiple networks.

“The softswitch only initiates signaling. It does not have routing and switching functions, which is why you need IP STP products,” said Sharon Chen, president and chief technical officer at SS8.

Using TRIP, the routing engine inside SS8’s SignalingSwitch will support networks deploying both session initiation protocol (SIP) as well as H.323. For SIP-based networks, SS8’s SignalingSwitch serves as a SIP proxy server, redirect server and registrar. For H.323-based network, the product serves as a gatekeeper. For all networks, the SignalingSwitch IP STP performs as a location server. It automatically propagates IP telephony routing information throughout the network.

“Without TRIP, dynamic allocation and routing of IP telephony calls in the softswitch is impossible,” Chen said.

Like the border gateway protocol 4 (BGP-4) on which it is based, TRIP uses dynamic allocation and routing to replace the static routing tables of a class 5 switch.

“A [class 5] switch has to know every other switch in the network. It is not very flexible. With TRIP, when one STP changes or one softswitch changes a number or adds a new area code, the whole network gets updated,” Chen said.

TRIP also gives the routing engine the ability to perform policy-based routing so service providers can define policies to reflect different service level agreements.