On 2/6/07, Erik R. Jensen <[EMAIL PROTECTED]> wrote:
Bryan Sant wrote:
> UDP is built on IP (and TCP is built on UDP)
TCP and UDP are both built on IP. TCP is not built on UDP.
TCP and UDP are peer protocols.
I apologize if it was just a typo, but wanted to clarify.
No typo, but it is wrong. When you look at a chart of the TCP/IP
stack you'll probably see the UDP and TCP protocols side-by-side.
However, TCP is actually a super-set of the features of UDP. In the
OSI network model, IP maps to layer 3 (network), UDP and TCP both map
to layer 4 (transport). However, if you could split layer 4 in two,
there would be a lower portion that UDP handles and a higher portion
that TCP handles.
UDP sends datagrams.
TCP manages datagrams with reliable delivery (acks, time-outs,
resends, etc), packet ordering, flow control/windowing, etc.
I am incorrect in stating that TCP is literally built on top of UDP.
I doubt they share any code, or that the TCP code is an addition to
the UDP code, but the TCP feature set is a super-set of UDP.
-Bryan
/*
PLUG: http://plug.org, #utah on irc.freenode.net
Unsubscribe: http://plug.org/mailman/options/plug
Don't fear the penguin.
*/
