BPSC TRE – Computer Networks: Data Link Layer & MAC Sublayer | Test 1

The LLC sublayer provides logical link control functions, including flow-control and error-control mechanisms in applicable IEEE 802 networks. The MAC sublayer is responsible for media access and MAC addressing, while physical signaling belongs to the Physical Layer.

Framing encapsulates network-layer packets into discrete data structures called frames, adding header and trailer synchronization flags so the receiver can detect the start and end of each packet.

Byte stuffing (or character stuffing) inserts an escape character (ESC) immediately before any inadvertent flag or escape byte in the data stream so the receiver treats it as raw data rather than a framing delimiter.

In HDLC and related protocols, whenever the sender transmits five consecutive '1' bits in the data payload, it automatically stuffs a '0' bit. This prevents user data from ever mimicking the six consecutive '1' bits of the flag delimiter (01111110).

An Ethernet MAC address is a 48-bit (6-byte) physical hardware address, typically represented as 12 hexadecimal digits separated by colons or hyphens (e.g., 00:1A:2B:3C:4D:5E).