Packet evolution

A big part of CenturyLink's long-distance network consolidation process is creating a path to enhance its packet-based service capabilities.

By establishing a demarcation point for SIP and the PSTN, the service provider deployed Sonus' suite of media gateways (GSX9000), policy management (PSX Call Routing and Policy Server) and its session border controller (NBS-9000).

Initially, the deployment capex reduction exercise, the Sonus equipment is being used for TDM to IP interconnection that's centrally managed.

"What they wanted to do was not interrupt services to their end users while becoming more capex efficient," said Aashu Virmani, Sr. Director, Marketing, Sonus. "In addition, they have other capabilities from Sonus they'll deploy in the future. Not only can they use these capabilities to enable VoIP, but also pass video and multimedia traffic."

Beal agreed, adding that Sonus had the capabilities to get up and running quickly for what is initially a Class 4 voice switching upgrade. Of course, the migration to a common LD network also forms the basis for an IMS network implementation.

"Given the time frame that we were allowing ourselves, we really needed to go with a vendor who would work right out of the box and take away the integration risk, but was next-gen focused to keep us open standards and implement an IP multimedia service (IMS) strategy in the near future," he said. 

While IMS has been through a long phase of initial hype and various meanings, CenturyLink sees it as an evolution from basic voice to multimedia and the normalization of feature sets. This evolution would apply to two domains: voice services and its ongoing IPTV investment. 

On the voice end, it would enable CenturyLink to launch new packet-based voice products, including IP Centrex and voice mail. Already, CenturyLink does provide IP Centrex in some markets and conducting SIP trunking trial. In addition, a lot of the traffic exchange on the long-distance network is native SIP already.

Although still early in the game, CenturyLink will also leverage the IMS network architecture for its ongoing IPTV network rollout. Currently, CenturyLink is running IPTV service over DSL including Wisconsin, Columbia, Mo. and Jefferson City, Mo.

"We have IPTV launched in a couple of markets and are proving our operational characteristics and our product its capabilities," Beal said. "We're pretty excited about the capabilities that [IPTV] gives us to serve our customers, which is obviously still in very early release."

And while other service providers talk about making network transformations, CenturyLink is making it happen today.

Beal says that for those that have been in the next gen network world for a while like himself see this latest build out to may seem to the outside as an evolution, but "from a vantage point of someone who has been in the next-gen world for a while that's the way it will seem, but to a lot of my colleagues it feels like a complete rewrite of our data and voice services business."

Packet evolution diagram

Packet evolution