tcp urgent data
Kurt Matthys
urgent data when an rfc793 compliant host is communicating with an
RFC 1122 compatible host. If the 793 host is sending, the 1122
host thinks that there is more urgent data than there really is. The
problem here is that Telnet is supposed to keep looking for the IAC
DM after running out of urgent data. The DM will be in the
penultimate byte of urgent data as far as the 1122 host is concerned.
Telnet will look at the last byte of what it thinks is urgent data,
see that it is not a DM, and continue discarding input. This is not
good.
One way to handle the situation is for the 1122 TCP to lie to Telnet,
saying that there is one less urgent byte than TCP thinks there is.
This will work whether the 1122 host is communicating with a 793 host
or a 1122 host. This sounds like a kludge to me, and is esthetically
not pleasing as TCP is now lying to the applications. Can someone
shed some light on this for me?
Kurt----------------------------------------------------------------------
Kurt Matthys
Unisys Corp Tel: (612) 635-5693
M.S. 4123 Fax: (612) 635-7523
P.O. Box 64942 email: ku...@rsvl.unisys.com
St. Paul, MN 55164 0942
----------------------------------------------------------------------
Bob Braden
*> I am wondering if there is a standard, approved way to handle tcp
*> urgent data when an rfc793 compliant host is communicating with an
*> RFC 1122 compatible host.
Kurt,
Just for the record, it is not 1122 VS. 793. As noted in 1122, 793
contained DIFFERENT definitions in two different places, and some people
did one, some did the other. 1122 just said which one to believe.
I think Dave Borman has worried this one to death; ask him.
Bob Braden