Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!dimacs.rutgers.edu!mips!ultra!wayne
From: wayne@ultra.com (Wayne Hathaway)
Newsgroups: comp.protocols.tcp-ip
Subject: Question on TCP use of IP TOS
Message-ID: <1991Jan21.200559.1426@ultra.com>
Date: 21 Jan 91 20:05:59 GMT
Reply-To: wayne@ultra.com (Wayne Hathaway)
Distribution: na
Organization: Ultra Network Technologies
Lines: 25

Can some expert out there please explain the relationship between IP
type of service (TOS) and TCP connection establishment?  In particular,

1) Host A does a LISTEN() without specifying an IP TOS.  Host B does a
   CONNECT(TOS=THROUGHPUT).  When host A sends segments to host B over
   this connection, what TOS should it use? 

2) Host A does a LISTEN(TOS=DELAY).  Host B does the same
   CONNECT(TOS=THROUGHPUT).  When host A sends segments to host B over
   this connection, what TOS should it use? 

Another way of asking this is "Is TOS somehow negotiated during
connection establishment, or does each end use what it wants
independent of the other?"

Finally, for data transfer it would seem best for the end sending the
data to say TOS=THROUGHPUT and the end sending the ACKs to say
TOS=DELAY; is this typically done?

Thanx much.

    Wayne Hathaway               domain: wayne@Ultra.COM
    Ultra Network Technologies     uucp: ...!ames!ultra!wayne
    101 Daggett Drive             phone: 408-922-0100 x132
    San Jose, CA 95134           direct: Hey, you!