TCP and UDP

[mahiapkum]

Hi all,
I am new to networking and i want to know why TCP is called a connection oriented even though we send out packets,n UDP called connectionless
Thanx in advance

[Banfa]

You send packets on both UDP and TCP. However a TCP connection is negotiated and once established it is then guaranteed. That is packets sent on a TCP connection are guaranteed to arrive in the correct order at the destination and if any packets go missing they will be re-requested as long as the connection remains "up".

On the other hand a UDP connection is not negotiated in the same way and is not guaranteed. That is packets are just fired at the destination by the source and there is no feedback as to if the arrive or not and in fact they are not guaranteed to arrive so if there is a lot of network congestion the network will drop UDP packets.

You may say why use UDP at all, well because there doesn't have to be an reverse communication that the data has arrived correctly (which there has to be for a guaranteed connection) it can achieve higher data throughput. It is often used for non-critical audio and video streaming as loosing the odd packet there is deemed acceptable.