Subject: [rohc] Regarding the TCP Options in the IR, IR-DYN Packets

From: [email-masked]
Date: Thu, 12 Mar 2009 11:09:22 +0000

Hi,
I am implementing the RoHC TCP Profile and I had a query
regarding the TCP Options. In Section 6.3.5 of RFC 4996
it is mentioned that the TCP options will be encoded by
setting all the X bits to 1 and then sent as part of the dynamic
chain in case of IR and IR-DYN packets.
But the IR or IR-DYN packet format doesn't contain any field
indicating the presence or absence of the options. The byte
following the dynamic chain could as well be a payload byte
in case the options are not present. So how should the options
be detected in case of the IR, IR-DYN packets?
Should the byte following the dynamic chain be checked for
the PS bit and the M bits and then a further check be
done to see if the X bits are set and then treat them as the
options or is there any other better way of doing this?

Regards,
Ray