DSCP Marking for selected TCP packets

anant.konchada · 05-24-2018, 01:24 AM

Hi, I have a special usecase to mark DSCP for selected packets on a given socket connection. I was able to set DSCP at socket connection (using setsockopt) and this is applied to all packets sent on that connection. But not finding a way to mark DSCP for only required packets. Can some one who already tried (any method) guide me on how to achieve this?

nini09 · 05-24-2018, 02:37 PM

What's your meaning, required packets?

anant.konchada · 05-24-2018, 11:27 PM

I mean instead of marking all packets sent on a given TCP connection.
I would like to mark DSCP value for some packets based on application content (in that packet) at the time of sending packet on that socket.
I am not finding any way to manage this while sending packet using socket send API. Is there a way using socket APIs or any alternate way?

nini09 · 05-25-2018, 02:44 PM

you can use raw socket to control any field in IP and TCP header. It request more code.

anant.konchada · 05-26-2018, 02:27 AM

Thanks nini09. Can you direct me to any sample, just for my reference. Thanks in advance.

nini09 · 05-30-2018, 03:01 PM

The link has example code of raw socket for UDP and TCP, http://www.tenouk.com/Module43a.html.