Global Crossing ripping out TDM switch

Global Crossing today announced it is decommissioning its first TDM switch in its network, moving the carrier closer to its goal of running an all IP network by the end of 2006.

The Alcatel switch in Chicago has been carrying less and less traffic as Global Crossing has been transferring more network traffic from the TDM switch to its Sonus softswitching architecture. The company plans to remove more legacy switches from the network later this year, starting with Los Angeles and moving up the chain of large markets.

"This is what we set out to do four years ago when we adopted voice over IP into our network," said Anthony Christie, chief marketing officer for Global Crossing. "We haven’t bought another TDM port for our network since. Now we’re actually removing TDM infrastructure. This is a big milestone for us."

Global Crossing’s convergence strategy has taken an inside out approach. The company started by using Sonus gear as end points to its long-haul routes, routing almost all of its international voice traffic IP. As it became comfortable with the softswitch architecture it began pushing it into the core, allowing it to take direct IP hand-offs from its carrier customers as well as convert its mainstay TDM traffic directly to IP when it hit the network.

The Chicago TDM switch used to be one of the most heavily trafficked of the network. At its peak it handled 80 million calls or 180 million minutes of voice traffic a month, so Chicago became one of the logical focus points for the new core softswitches. Traffic over the TDM switch as fallen dramatically over the last years as Global Crossing began routing more and more of its TDM traffic to the packet network. The decline finally reached the point where Global Crossing became comfortable with decommissioning the TDM switch entirely, transferring all remaining circuit-switched traffic in that market to IP, Christie said.

"Our softswitch became battle hardened," Christie said. "We became confident it could handle the whole load."

About 40% of Global Crossing’s voice traffic is routed IP, but the vast majority of it still hits its network TDM. While Christie doesn’t expect to see a vast increase in direct IP hand-off anytime soon, Global Crossing can at least get the extra cost savings of removing the final TDM hop on its own network. "We’re getting to the point that the second a minute of traffic hits our network, it’s IP," Christie said.