Udp/tcp

[MonkyMajik]

What difference does it make to an application if data it receives is delivered by UDP or by TCP?

 

[AllThingsGeek]

it makes a lot of difference to the host sending the data. for instance, pcanywhere:
pcanywhere uses UDP to send the status to the host indicating that it is still functioning properly. UDP doesn't require a response back from the remote client. it assumes that the data is making contact. however it uses TCP in order to send the data (screen refresh). if the remote administration pc doesn't respond to the screen refreshes then the host will assume that the connection speed needs to be altered or the connection was lost.

 

[m3trj]

TCP is where data is sent forward, and a reply is sent back from the other end to say the data got there alright.

UDP is where the data is just broadcast and no data is sent back. Usually used where there is no need for error correction.

 

[AllThingsGeek]

thanks, m3, sometimes i speak in "geek"

 

[fitzjj]

bit more to what has been said above:

since UDP does not send back an acknowledgement and there are no retransmissions of failed packets UDP is a good choice for things like video where you dont want to retransmit a failed frame because there would be a pause while you waited for the frame to retransmit and you are unlikely to notice one or two missed frames anyway. - in UDP you dont establish a connection you just fire packets (it is connectionless) - with TCP you establish a connection