WiMax provider Clearwire has struck a deal with Nortel Networks to provide VoIP service to their wireless broadband customers. While Clearwire currently offers VoIP in 37 of the company's 46 markets, this will be the first time they'll be doing so over their own infrastructure. Clearwire will use Nortel's Application Server (AS) 5200 to deliver SIP applications, and Nortel's Communication Server 2000, an IP multimedia softswitch that handles long distance and local number portability services. Remember of course that Echostar and DirecTV will be reselling Clearwire service, which means they may also be reselling this VoIP service eventually.