Cisco 3825 - Manual (Page 173)

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Cisco 3825 Mobile Wireless Edge Router Software Configuration Guide
OL-15667-03
Appendix A Cisco 3825 Mobile Wireless Edge Router RAN-O Command Reference
ip rtp header-compression
ip rtp header-compression
To enable Real-Time Transport Protocol (RTP) header compression, use the ip rtp header-compression
command 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]
Syntax Description
Defaults 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 Interface configuration
Command History
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.
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.
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-format keyword.
12.3(2)T This command was incorporated into Cisco IOS Release 12.3(2)T. This
command was modified to include the periodic-refresh keyword.
12.3(4)T This command was modified to include the ietf-format keyword.
12.2(25)S This command was incorporated.
12.4(2)MR This command was incorporated.