Headquarters: Reston, Va.

2008 Revenue: $4 billion

Channel Chief: Mark Vayda, president of Worldwide Sales

Why It's a Strategic Networking Partner: Siemens Enterprise Communications Group is a joint venture formed last fall that includes a few familiar networking names. Owned by private-equity firm Gores Group and Siemens AG, the venture brings together Siemens Enterprise Communications and the businesses of Enterasys Networks and SER Solutions, both of which are owned by Gores Group. The end result is a company with a full line of networking, VoIP and unified communications tools.