TCP Sliding Window

Understanding TCP's sliding window protocol

This easy networking question tests your grasp of how TCP manages flow control and reliable data transmission. The sliding window is a fundamental mechanism that allows a sender to transmit multiple segments without waiting for individual acknowledgements, while the receiver signals how much data it can buffer.

To answer questions in this area, you need to understand the relationship between the sender's window (the range of bytes it is permitted to send) and the receiver's advertised window (the space available in the receiver's buffer). As acknowledgements arrive, the window slides forward, allowing new data to be sent. This protocol balances throughput—by allowing pipelined transmission—against reliability and flow control.

• Window size advertisement and dynamic adjustment
• Sequence numbers and cumulative acknowledgements
• Relationship between send and receive buffers
• Window shrinkage and expansion scenarios