Packet Switching and Data Transmission

Vocabulary flashcards covering packet switching mechanisms, packet structure, transmission types, and error detection methods based on the provided lecture notes.

Packet switching

A process where data is broken into packets that travel independently across the network, possibly via different routes, and are reassembled at the destination.

Header

The part of a packet that contains the source IP, destination IP, packet number, and protocol.

Payload

The part of a packet containing the actual data being transmitted.

Trailer

The part of a packet containing error checking data, such as a checksum, and an end-of-packet marker.

Serial transmission

A transmission type where bits are sent one at a time along a single wire; it is more reliable over long distances.

Parallel transmission

A transmission type where multiple bits are sent simultaneously along multiple wires; it is faster over short distances but suffers from interference (skew) over long distances.

Half-duplex

A transmission mode where data travels in both directions, but only one direction at a time.

Full-duplex

A transmission mode where data travels in both directions simultaneously.

Parity check (even)

An error detection method where a parity bit is added so the total number of 1s in the byte is even; an error is detected if the count is odd at the receiver.

Checksum

A value calculated from the data before sending; the receiver recalculates it and detects an error if the values differ.

ARQ (Automatic Repeat reQuest)

An error detection system where the receiver requests a retransmission (NACK) if an error is detected or sends an acknowledgement (ACK) if received correctly.

NACK

A signal sent in ARQ to request the sender to retransmit the data if an error is detected.

ACK

An acknowledgement sent in ARQ if data is received correctly.

Check digit

A digit added to data, often calculated from other digits, used to detect errors in data entry or scanning.