On Fri, 5 Apr 2002, Michael Smith wrote: > The last time this came up for a TCP implementation I used to > maintain, our interpretation of Robustness Principle applied to this > problem dictated that we shouldn't send segments with checksum fields > set to all ones (that is, we shouldn't send ~(+0)), but that we had to > accept either ~(+0) or ~(-0) in received segments. > > Strictly speaking, either zero state is completely legal Not so. Please read RFC1624 sections 3-5. L. <L.Wood@surrey.ac.uk>PGP<http://www.ee.surrey.ac.uk/Personal/L.Wood/>