Type-of-service field during TCP Server connections

Hi there,

I’m running QNX 4.24 with the TCP/IP 4.25 packages.
I’ve a TCP server running on my system, which is contacted by a remote client over a WAN.
The WAN uses the Type-of-service/DSCP field in the IP header to prioritise packets.
However! On connection, the SYN-ACK packet is sent before I acquire the socket handle (i.e. before accept() returns), and so the first packet always escapes with a TOS of 0x00, and is promptly discarded by the (congested) routers.

Does anyone know of a way to preset the TOS before the three-way handshake takes place? I’ve tried using setsockopt on the listener socket, but the connection socket doesn’t seem to inherit the value.

Thanks,
Graeme