Why are sequence numbers in a sliding window link layer protocol generally smaller than those in TCP?

Question

Computer networks

Hello, I came across this question. I’ll clarify right away that it was taken from the exam, in the original it sounded like this: “Why are the sequence numbers in a link layer protocol with sliding window normally smaller than in the TCP protocol?”.

Answer 1

Question from the series "- Why is there only one engine, but four wheels ?!" :)
Actually, they have already answered - 1 byte is allocated for channel channels under SEQ, 4 bytes for TCP.

Answer 2

You probably looked at the questions in a very hardcore exam :) Because, according to Google, the sliding window mechanism is implemented not only in the operation of the TCP protocol (which everyone knows), but also when sending frames at the data link layer. The answer obviously lies in the numbering order: in TCP, each octet sent over the connection is considered as having a sequence number, but at the link level, the frames that fall into this sliding window are numbered directly, which, as I understand it, is clearly less than octets. Therefore, there are fewer serial numbers.

Answer 3

If we take the link layer protocol, then it still works at the level where there is no routing, only a local area network. If you send a queue of packets that do not receive an acknowledgment of receipt, then it makes no sense to send too many of them - in the local network there are other problems other than a slow channel (and collisions), other problems are unlikely to occur.
While on a WAN, the response speed can be slow due to the distance and complexity of routing rather than the thickness of the channel, and while a response from a remote server is received, many more packets can be sent "in advance".
But this is all theory, which led to the fact that two bytes (16 bits) are allocated for packet numbering in tcp / ip, with the possibility of expansion, and in most link layer protocols (link layer), it is usually used up to 1 bit (then there is one frame each), creating chains of several or several tens of packets / frames, but not hundreds or thousands.

Answer 4

There are two counter questions.
1) What substances did the author of the question use, and in general, where did IT come from?
2) What are the answers?