The Design And Implementation Of An H.323 Gateway System

Several years ago, only a few market explorers set foot in the VoIP realm. But now a day, it has already been able to give us the top-ranking reliable service. The H.323 recommedation that was devised for the interoperatability of VoIP gradually become a practical standard. The gateway defined by H.323 to act as a bridge between SCN and PSTN naturally is the key product of manufacturers in CT (Computer Telephony) industry.This paper is based on a successful implementation of an H.323 gateway system, which was realized by the project team that the author parcitipated in. In this paper, the author analyzes the H.323 protocol stack at first, then presents a detailed H.323 gateway system implementation on WindowsNT/2000, and brings forward an elaborate analysis of DM3 CT platform which was used by the gateway; in succsession, the author discusses the communication between that gateway and a gatekeeper; at last, sets forth the test result and ideas for future improvement.