> I am pretty much a novice when it comes to the networking code but
> the way I understand it is the MSS options are exchanged when a
> connection is created.  However the option length may not be
> constant during the lifetime of the connection (a host that sends
> SACK blocks, something I'm currently working on, is a good example
> of this).

The SACK issue is pretty thin, I think.  The only time that comes
into play is when you have bi-directional bulk transfer, I think.
And, that is pretty rare.  I.e., SACK makes the size of the ACKs
variable.  (Some people have suggested that timestamps should be
changed so that we only use them if our sending rate becomes "large"
such that we need them for PAWS, but that is just a theory at this
point.)  It seems to me that the end-point that opens the connection
passively can solve this problem.  That end-point know whether or
not timestamps will be used and can adjust things accordingly.

allman


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Mark Allman -- NASA GRC/BBN -- http://roland.grc.nasa.gov/~mallman/