Cisco 3825 - Manual (Page 176)

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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 tcp header-compression
ip tcp header-compression
To enable TCP header compression, use the ip tcp header-compression command in interface
configuration mode. To disable compression, use the no form of this command.
ip tcp header-compression [passive] [iphc-format] [ietf-format]
no ip tcp header-compression [passive] [iphc-format] [ietf-format]
Syntax Description
Defaults Disabled
For PPP interfaces, default format for header compression is the IPHC format.
For High-Level Data Link Control (HDLC) and Frame Relay interfaces, the default format is as
described in RFC 1144, Compressing TCP/IP Headers for Low-Speed Serial Links.
Command Modes Interface configuration
Command History
Usage Guidelines You can compress the headers of your TCP/IP packets in order to reduce the size of your packets. TCP
header compression is supported on serial lines using Frame Relay, HDLC, or PPP encapsulation. You
must enable compression on both ends of a serial connection. Compressing the TCP header can speed
up Telnet connections dramatically.
In general, TCP header compression is advantageous when your traffic consists of many small packets,
not for traffic that consists of large packets. Transaction processing (usually using terminals) tends to
use small packets and file transfers use large packets. This feature only compresses the TCP header, so
it has no effect on User Datagram Protocol (UDP) packets or other headers.
passive (Optional) Compresses outgoing TCP packets only if incoming TCP packets
on the same interface are compressed. If you do not specify the passive
keyword, all TCP 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 the header compression will be used.
Release Modification
10.0 This command was introduced.
12.0 This command was incorporated. This command was modified to include the
iphc-format keyword.
12.3(4)T This command was incorporated. This command was modified to include the
ietf-format keyword.
12.4(2)MR This command was incorporated.