Cisco MWR 1941-DC User Manual page 21

Cisco MWR 1941-DC Router with the Cisco IOS IP-RAN Feature Set
To configure RTP header compression when using Cisco IOS Release 12.3(11)T or later, use the
following commands while in multilink interface configuration mode:
Command
Step 1
RPM(config-if)# ip rtp header-compression ignore-id
Step 2
RPM(config-if)# ip rtp compression-connections
number
The MWR 1941-DC supports up to 1000 RTP header compression connections on an interface.
Note
Configuring the RTP/UDP Compression Flow Expiration Timeout Duration
To minimize traffic corruption, cUDP flows expire after a period of time during which no packets are
passed. When this user defined duration of inactivity occurs on a flow at the compressor, the compressor
sends a full header upon receiving a packet for that flow, or, if no new packet is received for that flow,
the compressor makes the CID for the flow available for new use. When a packet is received at the
decompressor after the duration of inactivity has been exceeded, the packet is dropped and a context state
message is sent to the compressor requesting a flow refresh.
The default expiration timeout is 5 seconds. The recommended value is 8 seconds.
Caution Failure of performance/latency scripts could occur if the expiration timeout duration is not changed to
the recommended 8 seconds.
To configure the duration of the cUDP flow expiration timeout, use the following command while in
multilink interface configuration mode:
Command
RPM(config-if)# ppp iphc max-time seconds
Purpose
Enables RTP header compression for serial
encapsulations and suppresses IP ID checking during
RTP compression.
Configures the total number of RTP header
compression connections on an interface.
By default, a total of 16 RTP compression
connections on an interface is supported.
Purpose
Specifies the duration of inactivity, in seconds, that
when exceeded causes the cUDP flow to expire.
Configuring Tasks
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