Command:

x25 map compressedtcp

Mode:

Router(config-if)#


Syntax:

x25 map compressedtcp ip-address [protocol2 address2 [...[protocol9address9]]]
x121-address [option]

no x25 map compressedtcp address [protocol2 address2 [...[protocol9address9]]]
x121-address


Syntax Description:

ip-address

IP address.

protocol

(Optional) The upper layer protocol to be associated with the X.121 address specified in this map. To specify a protocol, use the protocol's keyword as listed in the table below. As many as nine protocol and address pairs can be specified in one command line.

address

(Optional) Protocol address.

x121-address

X.121 address.

option

(Optional) The same options as those for the x25 map command; see Table earlier in this chapter.


Command Description:

To map compressed TCP traffic to an X.121 address, use the x25 map compressedtcp interface configuration command. To delete a TCP/IP header compression map for the link, use the no form of this command.

Cisco supports RFC 1144 TCP/IP header compression (THC) on serial lines using HDLC and X.25 encapsulation. THC encapsulation is only slightly different from other encapsulation traffic, but these differences are worth noting. The implementation of compressed TCP over X.25 uses one virtual circuit to pass the compressed packets. Any IP traffic (including standard TCP) is separate from TCH traffic; it is carried over separate IP encapsulation virtual circuits or identified separately in a multiprotocol virtual circuit. 


 

Note   If you specify both ip and compressedtcp in the same x25 map compressedtcp command, they must both specify the same IP address.


The nvc map option cannot be used for TCP/IP header compression, because only one virtual circuit can carry compressed TCP/IP header traffic to a given host.


Example:

The following example establishes a map for TCP/IP header compression on serial interface 4:

Router(config)#interface serial 4
Router(config-if)#ip tcp header-compression
Router(config-if)#x25 map compressedtcp 172.20.2.5 000000010300


Misconceptions:

 

None


Related commands:

 

x25 map

 


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