Motorola 110502USM001 User Guide - Page 42

RTP/UDP/IP Header Compression Motorola's Vanguard routers supports RTP/UDP/IP and/or UDP/IP header compression. As Implementation of shown in Figure 2-17, the Vanguard compresses the 40 byte header to between 2 to 4 RTP/UDP/IP Header bytes. If UDP checksum is being sent, the RTP/UDP/IP header is compressed from Compression 40 bytes to 4 bytes. If no UDP checksum is being sent, header compression is 40 bytes to 2 bytes. 40 Bytes IP UDP RTP Packet Voice/Data IP UDP RTP Packet Voice/Data 2 to 4 Bytes Figure 2-17. RTP/UDP/IP Header Compression Motorola's Vanguard products support: • header compression by traffic type - RTP/UDP/IP, UDP/IP, or both • header compression on a link-by-link basis • header compression of RTP/UDP/IP or UDP/IP packets carried over PPP or Frame Relay WAN links Options for Header The Vanguard products can support header compression in four different Compression configurations. Header compression can be enabled to: • Compress outgoing packets only; incoming compressed packets are not recognized for decompression. • Decompress the incoming compressed packets only; outgoing packets sent on an interface are not compressed. • Compress all the outgoing packets and decompress all the incoming compressed packets on an interface. In addition, header compression can be configured to autodetect the compression state of incoming and outgoing packets. If an incoming packet received on a link is compressed then the outgoing packets are also be compressed. 2-26 Vanguard Routing Model