what is best-effort traffic?

Question

it's about data traffic.

Answer 1

In the IP world, the 2 primary protocols used are TCP and UDP. TCP is "connection oriented" and UDP is "connectionless" or "best effort".

With TCP you establish a connection between two end points and then you agree on a "window", an amount of data that can be outstanding or unaknowledged at any given time. If you have too much unacknowledged data then you assume that the data was lost on it's way to the destination and so you retransmit that data. TCP uses sequence numbers to insure that all data is recieved, and that it is in the correct order.

UDP will simply transmit the data, will not make any effort to ensure that it was received, and will not make any effort to ensure that the data was received in the correct order.

The two protocols are useful in different situations, but often times even when UDP is used there will be something at a higher level (like the application itself) that will make sure that any required data is received and that it can be assembled correctly.

Answer 2

With TCP/IP traffic, whenever a packet of information is send, a confirmation is returned when it recieves it destination. That way if some of the information fails to get therough it can be retransmitted. If a section of your spreadsheet does not make it, you want it retransmitted.

With "best-effort" the data is simply sent and no confirmation is required. It is the network's "best effort" to get it there. But if it does not arrive it is not retransmitted. Usually used for things like streaming video and Voice over IP. If your phone call breaks up for a second, you don't want that retransmitted and arrive several seconds later out of order. You won't be able to understand the conversion if the words are out of order. You want it dropped instead.