How to Implement Sliding Window Protocol in Networking

TL;DR

The sliding window protocol allows sending multiple frames before requiring an acknowledgment, increasing bandwidth utilization compared to stop-and-wait. It uses a window size to determine how many frames can be sent before waiting for acknowledgments, and the window slides forward as frames are acknowledged, allowing new frames to be sent.

Transcript

in the last lecture we have seen the stop-and-wait protocol and the stop-and-wait a RQ protocol in today's lecture we will see the sliding window protocol let's start the session with the outcomes in today's session we have three outcomes let's see what are they upon the completion of this session the learner will be able to outcome number one unde... Read More

Key Insights

• The sliding window protocol enables multiple frames to be sent before acknowledgments arrive.
• The window size determines how many frames can be in flight before waiting for acknowledgments.
• Each frame has a sequence number to simplify tracking and ordering of frames.
• The sender transmits frames up to the window limit and then waits for acknowledgments.
• Acknowledgments allow the window to slide forward, freeing capacity for new frames.
• Frame 0 is acknowledged first, enabling the sender to transmit the next frame in sequence.
• As frames are acknowledged, the sender moves the window to include new frames in its range.
• If frames are not acknowledged promptly, the window prevents sending beyond the current limit, avoiding congestion.
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Questions & Answers

Q: A real search query about the topic: How does sliding window protocol improve bandwidth utilization?

The sliding window protocol improves bandwidth utilization by allowing multiple frames to be sent before an acknowledgment is received. The window size sets how many frames can be in transit at once, so the sender can keep sending within that limit while waiting for acknowledgments. This reduces idle time and makes better use of available bandwidth.

Q: What is the role of the window size in sliding window protocol?

The window size defines the number of frames that can be sent before any acknowledgment is required. It controls how many frames can be transmitted concurrently, enabling efficient use of the channel. As acknowledgments arrive, the window slides forward to include new frames, maintaining continuous data flow.

Q: How are frames tracked in sliding window protocol?

Frames are tracked using sequence numbers assigned to each frame, which helps the receiver organize incoming data and helps the sender know which frames have been acknowledged. This sequencing allows the sliding window to move forward accurately as acknowledgments arrive, ensuring proper order and progress.

Q: What happens when an acknowledgment is received in sliding window protocol?

When an acknowledgment for a specific frame is received, the sender slides the window forward to reflect the new acknowledged state and can send additional frames that were previously outside the window. This process continues, keeping the transmission efficient and in order.

Q: What problem does sliding window protocol address compared to stop-and-wait ARQ?

Sliding window protocol addresses the underutilization of bandwidth seen in stop-and-wait ARQ by allowing multiple frames to be in transit. This reduces idle time while waiting for acknowledgments and improves overall throughput, especially in networks with higher bandwidth where sending one frame at a time wastes capacity.

Q: How does the protocol ensure frame order during transmission?

Frame order is ensured by sequencing each frame and by the receiver acknowledging frames in sequence. The sender cannot advance beyond the last acknowledged frame, so the window slides in a controlled manner. This structured advancement maintains data integrity and proper ordering of frames.

Q: What is the relationship between sent frames, acknowledged frames, and the current window?

The sent frames that are acknowledged appear before the window, the frames that are sent but not yet acknowledged occupy the middle portion, and the frames not yet sent stay in the tail. The window moves as acknowledgments arrive, expanding to include new frames and shrinking the acknowledged region.

Q: Can the sliding window protocol adapt to varying network conditions?

Yes, by adjusting the window size, the protocol can adapt to different network conditions. A larger window increases parallelism and throughput on reliable links, while a smaller window reduces potential congestion on lossy channels. Dynamic window sizing helps balance throughput and reliability under changing conditions.

Summary & Key Takeaways

• Sliding window protocol improves utilization by sending several frames before acknowledgments arrive, unlike stop-and-wait.

• Frame sequencing and a moving window maintain order and track acknowledgments as the window slides.

• Understanding window size and acknowledgment flow is essential to grasp how this protocol manages transmission efficiency.