102 | Managing the Radio
Aprisa SRx User Manual 1.3.0
DATA COMPRESSION
IP Header Compression Ratio
The IP Header Compression implements TCP/IP ROHC v2 (Robust Header Compression v2. RFC4995,
RFC5225, RFC4996) to compress the IP header. IP header compression allows for faster point-to-point
transactions, but only in a star network.
IP Header Compression module comprises of two main components, compressor and decompressor. Both
these components maintain some state information for an IP flow to achieve header compression.
However, for reasons like packet drops or station reboots this state information can go out of sync
between the compressor and decompressor resulting in compression and/or decompression failure
resulting in loss of packets.
The compression ratio controls the rate at which compressor and decompressor synchronize state
information with each other. Frequent synchronization results in reduced ratio.
Option
Function
Compression
Disabled
Disables IP header compression.
High
State information is synchronized less frequently thus achieving
the best compression ratio.
Medium
State information is synchronization less frequently than ‘High’
setting but more frequently than ‘Low’ setting.
Low
State information is synchronized frequently thus reducing the
compression ratio.
The default setting is High.
When IP Header Compression is enabled, it is important that the Network Radius is set correctly. If it was
incorrectly set to 1, header compression could not be interpreted by radius 2 radios.
