Answer and Explanation:
Reliability is important because if the service lacks lacks reliability this could mean losing a packet or acknowledgement which then requires retransmission.
Delay can be tolerable in different degrees by applications, for example online chatting or conferences need to have the minimum delay possible.
Jitter is the variation in delay for packets belonging to the same flow.
High Jitter: difference between delays is large
Low jitter: difference between delays is small.
Bandwidth depends on the application. In video conferences, for example, there is a need to send million of bits per second to refresh a colour screen while sending a email may not reach even a million.
