> > to fragment, i.e., use datagrams that no longer consist of a single
> > packet, then the whole reason for using datagrams has disappeared.
> this confuses me, what about fragmentation removes the whole reason for
> using datagrams. IP itself is a datagram, and must be able to be
> fragmented. Fragmentation is necessary to allow larger packets to
> travel over networks with smaller MTUs. So unless you are using something
> with MTU discovery, or a homogenous network, it is always possible that
> you are always going to need to use fragmentation. I understood (was
> taught) that datagrams were connectionless and unreliable. Nothing was
> ever mentioned that they had to stay as complete units, and could not be
> broken up and put back together at the other end...
>
> -chris
>
> *************************************************************
> Christopher Rogers Stevens Institute of Technology
> Email:gandalf@pobox.com
> HomePage http://stute.jacobus.stevens-tech.edu/~gandalf
> *************************************************************
>
> It has recently been discovered that research causes cancer in rats.
it is precisely because udp is connectionless and unreliable that you
can split a udp packet....you could split one up, you would either have
to put them back together in the proper order at the distant end, in
which case you should use tcp instead, and it would completely negate
the advantage (as it were) of using udp, or at least there would no
longer be a reason to use it...or some of the fractional udp packets
would have the possibility of getting lost or returning in the wrong
order, which would make the data in the packets anywhere from useless to
harmful...
-- Lance Dillon | "Not in the face, UNIX/NT Sysadmin | not in the face!" Booz-Allen & Hamilton, Inc. | -- Arthur http://home1.gte.net/riffraff/ |