Question

How does GBN protocol detect lost or overly delayed packet

a) Timeout mechanism
b) Selective repeat
c) Sliding window
d) Error correction

Answer 1

The GBN protocol uses a Timeout mechanism and Sliding window to detect lost or overly delayed packets. Error correction is not used for this purpose.The correct option is A.

Step-by-step explanation:

The GBN (Go-Back-N) protocol detects lost or overly delayed packets using a) Timeout mechanism and c) Sliding window.

1. Timeout Mechanism: GBN protocol uses a fixed timeout value. If an acknowledgment for a packet is not received within this timeout period, the sender assumes that the packet is lost and retransmits it.
2. Sliding Window: GBN protocol maintains a sliding window at the sender and receiver sides. The sender keeps a track of the acknowledgments received for each packet it sends. If an acknowledgment is not received within a certain time, the sender assumes that the packet is lost and retransmits it.

d) Error correction is not directly used by the GBN protocol to detect lost or overly delayed packets.