Travis Russell is Regional Sales Manager of the Network Switching Division at Tekelec in North Carolina. He has been a field engineer in the telecommunications business for over 20 years, and lectures on basic telecommunications at area colleges and universities, as well as industry seminars. He is the author of Telecommunications Protocols, Signaling System #7, and the co-author of CDPD: Cellular Digital Packet Data Standards and Technology, all published by McGraw-Hill.