victor@kuling.UUCP (Bjorn Victor) (04/21/87)
As I'm working on a TCP implementation, I have a question on the
interpretation of RFC 793 (please look in your copy):
On page 73 (Segment Arrives, otherwise clause, ACK bit clause), in
state FIN-WAIT-1, it says
"..., if our FIN is now acknowledged then enter FIN-WAIT-2 and
continue processing in that state."
On page 75 (Segment Arrives, otherwise clause, FIN bit clause), in
state FIN-WAIT-1, it says
"If our FIN has been ACKed (perhaps in this segment), then enter
TIME-WAIT, ..."
Now, could somebody please explain how we could possibly "execute" the
quoted sentence on page 75? If our FIN *was* ACKed, we're no longer
in the FIN-WAIT-1 state!?
Also, if someone could point me to a more formal description of TCP,
I'd be more than happy.
--Bjorn Victor UUCP: {mcvax,seismo}!enea!kuling!victor
Dept. of Computer Systems ARPA: Victor%Carmen.UU.SE@Seismo.CSS.GOV,
Uppsala University, SWEDEN victor%kuling.UU.SE@Seismo.CSS.GOV
--
--Bjorn Victor UUCP: {mcvax,seismo}!enea!kuling!victor
Dept. of Computer Systems ARPA: Victor%Carmen.UU.SE@Seismo.CSS.GOV,
Uppsala University, SWEDEN victor%kuling.UU.SE@Seismo.CSS.GOVCLYNN@G.BBN.COM.UUCP (04/22/87)
Bjorn, Technically, you can't; in fact, the next paragraph on page 75, FIN-WAIT-2, says to do exactly the same thing as does the FIN-WAIT-1 state when the FIN has been acked. I view the situation as an explicit restatement of robustness -- a correct implementation shouldn't get into that state, but if it does (software implementations have been known to contain bugs) then there is a way to recover. Maybe there should be a statement to the effect that you shouldn't be here, write an entry into the system error log. Charlie
PADLIPSKY@A.ISI.EDU (Michael Padlipsky) (04/24/87)
A great deal of time and trouble went into making "MIL-STD-1778"
("Military Standard Transmission Control Protocol") APPEAR to be more
formal than the RFC TCP spec. It would be interesting to learn if
a relatively neutral observer thought it actually IS more formal--
and, as a purist's point, whether that makes it more useful, since
I doubt there's an a priori correlation between formality and utility.
Given that page ii says that "benefical comments" can go to
Defense Communications Agency
ATTN: J110
1860 Wiehle Avenue
Reston, VA 22090
and that I don't see any "ordering information" elsewhere (not that
it's necessarily not there, just that I don't see it), presumably
a request for a copy could go to that address as well with some chance
of being fulfilled.
cheers, map
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