rohc team mailing list archive

[Didier Barvaux <didier@xxxxxxxxxxx>]

Hi,

> I am trying to write a custom code for an InterSwitch Link (ISL), can
> you please advise how I can compress the headers
> of all the Ethernet frames that goes through the link between the two
> Layer 2 switches ?.
> The ISL is just a simplified bridge.

The ROHC protocol does not compress the Ethernet header itself, so
for better efficiency you should leave the Ethernet header unchanged,
and compress the Ethernet payload with the ROHC library.

In short:
 a/ skip the Ethernet header,
 b/ compress the Ethernet payload (possibly IPv4 or IPv6) with the
    ROHC library,
 c/ copy the Ethernet header you skipped before the ROHC packet so
    that your compressed packet can be handled by the Ethernet network.

You may find an example within the non-regression test of the library.
The non-regression test gets an Ethernet packet from a capture file,
skips its header, compresses its payload, adds back the header, then
writes the resulting frame to a another capture file. See
http://bazaar.launchpad.net/~didier-barvaux/rohc/main/view/head:/test/non_regression/test_non_regression.c#L451

I hope I was clear enough. If not, tell me.

Regards,
Didier

Attachment: signature.asc
Description: PGP signature