Per-packet IP DSCP/TOS Marking
It is interesting to know whether there is a way to conditionally mark *each* outgoing IP packet with a *different* DSCP/TOS marking?
Basically: If I have a TCP socket which is used by 2 different applications, each of which generates a particular kind of data; Is it possible to mark some flag using socket API's (or otherwise), which informs IP layer to perform DSCP marking based on the flag set?
I write a program to do the following:
==> Open socket.
==> If data is from application A, set flag abc.
Or if data is from application B, set flag xyz.
And, when it reaches IP, it:
==> Marks DSCP field of the packet with 11 if flag abc is set;
==> Marks DSCP field of the packet with 22 if flag xyz is set.
Thanks for any pointers or suggestions.