3com MSR 20-20 참조 매뉴얼

C

HAPTER

 22: F

RAME

 R

ELAY

 C

ONFIGURATION

 C

OMMANDS

Frame relay interface view

None

Use the fr compression iphc command to enable FRF.20 (FRF.20 IPHC) 
compression.

Use the undo fr compression iphc command to disable the function.

By default, the frame relay compression function is disabled.

The system supports frame relay FRF.20 IP Header Compression (IPHC) function 
that compresses IP header. This technology is used to transmit voice messages so 
as to save bandwidth, and data is transmitted with great efficiency and speed.

Messages are divided into control messages and data messages according to 
FRF.20. An control message is used for state negotiation between the two sides 
that have compression protocol enabled of a DLCI connection. FRF.20 data 
messages are exchanged only after the negotiation succeeds. The negotiation fails 
if the number of FRF.20 control messages sent exceeds. In this case, compression 
configuration cannot take effect. This command is only valid for RTP messages and 
TCP ACK messages.

You can specify FRF.20 (FRF.20 IPHC) compression function using either the fr 
compression iphc command or configuring static address mapping.

For detailed information about configuring static address mapping, refer to “fr 
map ip” on page 396.

# Configure the frame relay interface Serial 2/0 to adopt FRF.20 compression.

<Sysname> system-view

[Sysname] interface serial 2/0

[Sysname-Serial2/0] fr compression iphc 

fr dlci dlci-number

undo fr dlci [ dlci-number ]

Interface view

dlci-number: Virtual circuit number allocated for the frame relay interface, in the 
range 16 to 1007. The range 0 to 15 and 1008 to 1023 are reserved for special 
purposes.

Use the fr dlci command to configure the virtual circuit for frame relay interface 
and enter the corresponding virtual circuit view on the frame relay.