Entry

what is different between TCP & UDP ?

Feb 16th, 2006 04:40
Devis Lucato, Chunnu pandya,

There are four major differences between UDP and TCP:
1. TCP can establish a Connection, UDP cannot;
2. TCP provides a stream of unlimited length, UDP sends small packets;
3. TCP guarantees that as long as you have a connection data sent will
arrive at the destination, UDP provides no guaranteed delivery;
4. UDP is faster for sending small amounts of data since no connection
setup is required, the data can be sent in less time than it takes for TCP
to establish a connection.
Related to 2 above is the fact that UDP packets are limited in size, with
the extact size limit being determined potentially on a per-system basis.
IIRC studies have shown that 1400 bytes is a safe maximum size, and 900
bytes is even safer.
Related to 3 above is the fact that UDP packets may simply disappear in
transit. Routers may toss them if there's a lot of traffic at any given
moment, and the receiving system may not have room to buffer them when
received.