Cisco Systems 3825 manual Ip rtp header-compression, Iphc-format, Ietf-format, Periodic-refresh

Appendix A Cisco 3825 Mobile Wireless Edge Router RAN-O Command Reference

ip rtp header-compression

ip rtp header-compression

Syntax Description

Defaults

To enable Real-Time Transport Protocol (RTP) header compression, use the ip rtp header-compressioncommand in interface configuration mode. To disable RTP header compression, use the no form of this command.

ip rtp header-compression [passive iphc-format ietf-format][periodic-refresh]no ip rtp header-compression [passive iphc-format ietf-format][periodic-refresh]

passive	(Optional) Compresses outgoing RTP packets only if incoming RTP packets on
	the same interface are compressed. If you do not specify the passive keyword, all
	RTP packets are compressed.
iphc-format	(Optional) Indicates that the IP Header Compression (IPHC) format of header
	compression will be used.
ietf-format	(Optional) Indicates that the Internet Engineering Task Force (IETF) format of
	header compression will be used.
periodic-refresh	(Optional) Indicates that the compressed IP header will be refreshed periodically.

Disabled

For PPP interfaces, the default format for header compression is the IPHC format.

For High-Level Data Link Control (HDLC) and Frame Relay interfaces, the default format for header compression is the original proprietary Cisco format. The maximum number of compression connections for the proprietary Cisco format is 256.

Command Modes

Command History

Interface configuration

Release	Modification
11.3	This command was introduced.
12.0	This command was incorporated into Cisco IOS Release 12.0. This command
	was modified to include the iphc-formatkeyword.
12.3(2)T	This command was incorporated into Cisco IOS Release 12.3(2)T. This
	command was modified to include the periodic-refreshkeyword.
12.3(4)T	This command was modified to include the ietf-formatkeyword.
12.2(25)S	This command was incorporated.
12.4(2)MR	This command was incorporated.

Usage Guidelines You can compress IP/UDP/RTP headers to reduce the size of your packets. Compressing headers is especially useful for RTP because RTP payload size can be as small as 20 bytes, and the uncompressed header is 40 bytes.

	Cisco 3825 Mobile Wireless Edge Router Software Configuration Guide
OL-15667-03		A-41