What distinguishes the sliding window protocol in TCP's flow control mechanism?It relies on a single acknowledgement per segmentIt uses cumulative acknowledgementsIt does not allow for out-of-order deliveryIt employs hop-by-hop flow control

The sliding window protocol in TCP's flow control mechanism is distinguished by several key features:

1. Cumulative Acknowledgements: Unlike protocols that rely on a single acknowledgement per segment, the sliding window protocol uses cumulative acknowledgements. This means that the receiver sends an acknowledgement indicating the next byte it expects to receive, which implicitly acknowledges receipt of all previous bytes.

2. Out-of-Order Delivery: The sliding window protocol allows for out-of-order delivery. This means that if a segment is lost or delayed in transit, subsequent segments can still be received and processed by the receiver. This is in contrast to protocols that require strict in-order delivery of segments.

3. End-to-End Flow Control: The sliding window protocol employs end-to-end flow control, rather than hop-by-hop flow control. This means that the sender adjusts its transmission rate based on feedback from the receiver, rather than based on feedback from each intermediate node along the transmission path. This allows for more efficient use of network resources, as it avoids the need for each node to maintain state information about each active connection.