Compression of fragmented IPv4 packets ?

> I get fragmented IPv4 packets and want to compress these packages. Do you think I can get a compression gain that way using the ROHC algorithm?

The IP-only, TCP, UDP, ESP and RTP profiles do not support fragmented IPv4 packets, so the Uncompressed profile is used as fallback. The Uncompressed profile provide no compression gain at all.

So, ROHC won't provide any bandwidth gain for fragmented IPv4 packets.

You might however be able to avoid fragmented IPv4 packets at all. Maybe you are able to decrease the MTU (or the MSS for TCP) configured on both endpoints. Either manually, or with ad-hoc protocols such as Path MTU (PMTU) discovery.