Edge Of The Service Access Gateway

Solution of NAT/FW traversing is the main function of border service access gateway . The border service access gateway shielded the topology of private network.in another word ,The core component of a soft switch network is protected by the border service access gateway . The gateway is still a developing entity.its main function are interconnection,security and access control.The paper is divided into three chapters, introduces the present solutions of firewall/network address translation traversing and practical application of jitter buffer to solve time delay jitter of voice packet.The first part mainly describes porting of the ORTP stack from linux platform to vxworks and implementation of RTP related subsystem of the VoIP gateway . another part of the paper give a brief introduction to implementation of Cone/Symmetry NAT tunnel for SIP and RTP , and firewall traversing when the VoIP gateway is placed in private network .