The developer of a file transfer application-layer protocol that works over the
ID: 3768688 • Letter: T
Question
The developer of a file transfer application-layer protocol that works over the TCP/IP stack has to select a transport layer that works on top of IP v4. What is the correct answer from the following?
a.select UDP because datagrams are not lost, nor reordered and implementing protocols on top of a best effort datagram transport is very simple
b. select UDP because the file transfer protocol can run as a user-level process, not like with TCP or SCTP
c. select TCP because it already implements error, flow, and congestion control, even though path capacity may not be used optimally
d. cannot use SCTP since this protocol does not do error and flow control, just like UDP
a.select UDP because datagrams are not lost, nor reordered and implementing protocols on top of a best effort datagram transport is very simple
b. select UDP because the file transfer protocol can run as a user-level process, not like with TCP or SCTP
c. select TCP because it already implements error, flow, and congestion control, even though path capacity may not be used optimally
d. cannot use SCTP since this protocol does not do error and flow control, just like UDP
Explanation / Answer
Answer:
c) select TCP because it already implements error, flow, and congestion control, even though path capacity may not be used optimally.
Reason:
UDP typically gives higher throughput and shorter latency, and is therefore often used for real-time multimedia communication where packet loss occasionally can be accepted, for example IP-TV and IP-telephony, and for online computer games.However, in case of File transfer, initially the developer should provide reliability even though the transfer speed will be less in TCP.