Question
The transport layer protocols used for real time multimedia, file transfer, DNS and email, respectively are
Official answer and solution
- Official answer
- C
- From
- Official GATE 2013 answer key
Solution
Recall the standard transport layer protocol (TCP or UDP) used by key network applications.
Let us examine the requirements of each application:
- Real-time multimedia (VoIP, video streaming): Requires low latency and minimal jitter; packet loss can be tolerated, so it uses UDP.
- File transfer (FTP): Requires 100% reliable and in-order delivery of data bytes, so it uses TCP.
- DNS (Domain Name System): Typically uses short single-request single-response query messages where handshake overhead is undesirable, so it uses UDP on port 53.
- Email (SMTP / POP3 / IMAP): Requires completely reliable transport for message transmission, so it uses TCP.
Therefore, the protocols are UDP, TCP, UDP and TCP.
Final answer
Option (C)
Common trap
Assuming DNS always uses TCP, whereas standard DNS lookups primarily use UDP.
The answer is the one in the official GATE answer key. The solution is this site's own explanation.
Source
- Paper
- GATE 2013 Computer Science and Information Technology (CS)
- Question
- 12 of 65, printed as CS Q.12
- Section
- Computer Science and Information Technology
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