User Manual - Configuration Guide (Volume 3)
Versatile Routing Platform Chapter 5
IPHC Configuration
5-2
5.2 IPHC Configuration

5.2.1 Configuration Task List of IPHC

The configuration tasks of IPHC include:
z Enable/disable RTP header compression
z Configure the maximum connection number of RTP header compressions
z Configure the maximum connection number of TCP header compressions
z Configure the enabling of the Cisco-compatible RTP header compression
z Configure the removal of udp_chk field in the UDP header.

5.2.2 Enable/disable RTP header compression

When RTP header compression is enabled, TCP header compression will be enabled
accordingl. If the RTP header compression is disabled, the TCP header compres sion
will also be disabled.
Please make the following configuration in the interface configurat ion mode.
Table VC-5-1 Enable/Disable RTP header compression
Operation Command
Enable RTP header compression ip rtp header-compression
Disable RTP header compression no ip rtp header-compression
By default, the interface will not perform RTP header compression on the pack et.
It should be pointed out for notice here,
1) The subscriber must configure RTP header compression command on both ends
of the links at the same time.
2) After TCP header compression is enabled, fast forwarding will not be perf ormed
on the packet compressed.
3) After the configuration is completed, only when the shutdown and no shutdown
operation are performed on the interface can the configuration take eff ect.

5.2.3. Configure the Max. Connection Number of RTP Header Compressions

The subscriber can specify the maximum connection number on an interface that
performs RTP header compression.
Please perform the following configurations in interface configur ation mode.
Table VC-5-2 Configure the maximum connection number of RTP header compression
Operation Command
Configure the maximum connection number of RTP header
compression ip rtp compression-connections number
Restore the default value of the maximum connection number of
RTP header compression no ip rtp compression-connections
By default, the maximum connection number of TCP header compression that the
interface allows is 16. The value ranges from 4 to 1000.