The TCP sliding window protocol is a flow control mechanism that allows a sender to transmit multiple data packets (or bytes) before needing an acknowledgment (ACK), significantly improving network efficiency over "stop-and-wait" methods. It enables reliable, in-order delivery by managing a "window" of permitted packets, adjusting the amount of data in transit to avoid overwhelming the receiver.
- Window Size: Defines the number of bytes the sender can send before receiving an ACK.
- Dynamic Adjustment: The receiver notifies the sender of its available buffer space (receiver window) in its ACKs, allowing the sender to increase or decrease its sending rate dynamically.
- Flow Control: If the receiver's buffer fills up, it can shrink the window size (even to zero) to halt transmission, preventing buffer overflow.
- How it Slides: As the receiver acknowledges received data (ACK), the sender "slides" the window forward, permitting new segments to be transmitted.
- Sequence Numbers: Each byte is numbered to detect packet loss and reorder packets, ensuring reliable, ordered delivery. This protocol balances throughput and network load, making it crucial for modern network performance
We show three different protocols here
- Stop and Wait -the simplest and most inneficient
- The Go Back N - protocol
- The Selective Repeat protocol
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