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<TITLE>Re: [e2e] Are we doing sliding window in the Internet?</TITLE>
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<DIV id=idOWAReplyText74238 dir=ltr>
<DIV dir=ltr><FONT face=Arial color=#000000 size=2></FONT> </DIV></DIV>
<DIV dir=ltr>Joe Touch wrote :<BR><FONT size=2><BR>>> Do these semantic
wranglings actually have a point?<BR><BR>> The question is "under what
conditions is it permissible to override a<BR>> SHOULD". I would hope that
would be clarified in an update to 2119, but<BR>> don't know what the state
of that doc is...<BR><BR>1. The technical issue in question is QuickAck,
where delayed acks are not used for the first R / 2 bytes of received data,
where R seems to be the receive socket buffer size</FONT></DIV>
<DIV dir=ltr><FONT size=2>2. QuickAck is enabled in Linux, by default.
There is no procedure to disable it, except temporarily, for an application via
a system call.</FONT></DIV>
<DIV dir=ltr><FONT size=2>
<DIV dir=ltr><FONT size=2>3. </FONT><FONT size=2>Linux supports many other
"non-standard" TCP features, but most/all of them seem to be disabled by
default.</FONT></DIV></FONT></DIV>
<DIV dir=ltr><FONT size=2>4. There does not seem to be a whole lot of
technical documentation on the feature, except for the Linux man page. It is not
clear how this feature gets turned on and off during the life of a connection.
There is no RFC on the subject.</FONT></DIV>
<DIV dir=ltr><FONT size=2>5. It seems to violate a "SHOULD" statement in the
RFCs. </FONT></DIV>
<DIV dir=ltr><FONT size=2>6. It's objective is certainly not nefarious. It
improves performance for individual short data transfers. Perhaps the SHOULD
needs to be changed with some qualifications. But that requires an
open discussion.</FONT></DIV>
<DIV dir=ltr><FONT size=2></FONT> </DIV>
<DIV dir=ltr><FONT size=2>It is perhaps understandable that SHOULDs and even
MUSTs can be violated in controlled experimental environments (e.g.,
simulations).</FONT></DIV>
<DIV dir=ltr><FONT size=2>
<DIV dir=ltr><FONT size=2>It is perhaps understandable that SHOULDs may be
violated in controlled , isolated environments (e.g., satellite
networks).</FONT></DIV>
<DIV dir=ltr>
<DIV dir=ltr><FONT size=2>It may be unavoidable that a SHOULD or MUST
is violated by a "hacker" and used over over the
Internet.</FONT></DIV>But under what circumstances should a SHOULD be violated
and let loose over the Internet as part of a widely used OS?</DIV>
<DIV dir=ltr> </DIV>
<DIV dir=ltr>One would like to think that the last category should require some
care and a rigorous process. Is this process not documented or well understood?
Surely, it cannot be - implement, deploy, publish paper and write RFC :). What
role should the IETF play in this process? Advisory only?</DIV>
<DIV dir=ltr> </DIV>
<DIV dir=ltr>Anil</DIV>
<DIV dir=ltr>-----</DIV>
<DIV dir=ltr>Anil Agarwal</DIV>
<DIV dir=ltr>ViaSat Inc.</DIV>
<DIV dir=ltr> </DIV></DIV></FONT><FONT size=2></FONT>
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