4RF Aprisa SR+, User Manual

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Managing the Radio | 147
Aprisa SR+ User Manual 1.11.1
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 more frequently than ‘High’
setting but less frequently than ‘Low’ setting.
Low State information is synchronized frequently thus reducing the
compression ratio.
The default setting is High.