Best Guide to Understanding the Operation of Stop-and-Wait Protocol

With the setup of multiple network channels, the difficulty of controlling the transmission of data and information between the sender and receiver side has also significantly increased. In this article on ‘Stop-and-Wait Protocol,’ we will learn to control and maintain efficient data flow through the stop-and-wait data exchange method.

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What Is Stop-and-Wait Protocol?

To begin with, let’s look into some basic information about the protocol to understand the working of the stop-and-wait protocol better.


  • The Stop-and-wait protocol is a data exchange method designed to be active in the data link layer of the OSI model and is used in the data exchange between network devices in noiseless channels.


  • This protocol is designed to transfer data in a unidirectional data flow without application for error detection services.


  • The most important point of this protocol is based on the acknowledgment-based data transmission, i.e., the sender side will wait for the next data transfer until it receives the acknowledgment from the receiver side.

Next, we will look into the steps involved in the stop-and-wait protocol.

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Steps Involved in the Protocol

There are two main steps involved in the working of the stop-and-wait protocol that is required in the data exchange process:

Sender Side

Step 1: Transmission of one data unit at a time.

Step 2: The sender side will send the next data unit unless the receiver send’s the acknowledgment signal.

Receiver Side

Step 1: This side will receive the data sent by the sender side and use it.

Step 2:  After the receiver side uses the data, it will send the acknowledgment signal to the sender’s side for the next data transmission.

Now let’s move on to the working procedure of the protocol.

Working on the Stop-and-Wait Protocol

To better understand the working of the protocol, we will divide the data exchange method into steps:


  1. For the first step, the sender side will share the data with the receiver end for it to use.
  2. Then, according to the stop-and-wait method, the sender side will wait for the receiver's end to share the acknowledgment for data exchange to take place.
  3. The receiver side will use the data received and send the acknowledgment signal to the sender side.
  4. After receiving the acknowledgment, the sender end will share the next data unit.
  5. The exchange of data is continued for N no. of packets.

Then let’s move on to the drawbacks of applying the stop-and-wait protocol.

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Drawbacks of Applying the Protocol

Even if the protocol provides the network with various benefits, it also falls short in some cases. Some of the drawbacks of the stop-and-wait protocol are:

1. Data Loss During the Transmission Between Network Devices.


The issue is when the data is not received by the receiver, or the acknowledgment is not received by the sender side.

2. Issues With Sharing the Acknowledgment With the Sender End.


If no acknowledgment is received, the data exchange is paused from the sender side due to no error flow and control in the network.

3. Delay in Reaching the Acknowledgment to the Sender End.

The acknowledgment received after the time-out session is discarded by the sender end and halts the data transmission.


After completing this heading, we have covered all the parts needed to understand the stop-and-wait protocol.

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In this article on ‘Stop-and-Wait Protocol,’ we understood the importance of the network method that governs the data transmission between the devices in a communication channel. Then we also looked into the steps involved and working of the stop-and-wait protocol in the network.

If you want to learn more about the topic related to a network protocol and look further into the stop-and-wait protocol, you can refer to Simplilearn’s Cyber Security Expert course. This expert will help you train in the topics related to a network protocol and its deeply rooted need in a network channel.

Do you have any questions about this article on ‘Stop-and-Wait Protocol’. If yes, feel free to include them in the comment section at the bottom of this page. The Simplilearn team will help you solve your queries ASAP.

About the Author

Anmol KapoorAnmol Kapoor

Anmol is a Research Analyst who aims to become a Data Scientist one day. He enjoys Data Management systems and analysis. You will find him reading a book when he is not working.

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