How to replace one variable into TOS

[haojianmao]

Now I want to define one struct time by myself, and I catch the delay time between rx and ip_rcv, but I come across one problem. That's how I can replace the time into TOS when the packets are transmitting in networking. Thank you so much!

[andy-shev]

This is kinda question to StackOverflow, not related to Intel Edison board.