Marty,
Actually I was proposing that this be handled outside of setting TOS bits, but I wasn't clear. basically if I own a router from cisco today i can prioritize my interface traffic using the "priority-list" command. i select by protocol. Could that concept be built on to give me per port control over my routing in the future? who knows.
What you're trying to do is basically what TOS does: choose your outgoing path based on whether the application is most concerned about delay, throughput, or whatever. yes. When a host doesn't set any TOS bits, a router could conceivably then peek into the packet to look at TCP ports as part of computing the next hop. However, a router that did so would probably still want to leverage off of the TOS mechanism by using the TCP ports to determine what TOS bits the host should (according to Host Requirements) have set. agreed. the router could send a ICMP SET_YOUR_TOS_BIT,_DUMMY to the host. ;-) m