Sliding Window Protocol Program in C and C++

Here you will get sliding window protocol program in C.

In computer networks sliding window protocol is a method to transmit data on a network. Sliding window protocol is applied on the Data Link Layer of OSI model. At data link layer data is in the form of frames. In Networking, Window simply means a buffer which has data frames that needs to be transmitted.

Both sender and receiver agrees on some window size. If window size=w then after sending w frames sender waits for the acknowledgement (ack) of the first frame.

As soon as sender receives the acknowledgement of a frame it is replaced by the next frames to be transmitted by the sender. If receiver sends a collective or cumulative acknowledgement to sender then it understands that more than one frames are properly received, for eg:- if ack of frame 3 is received it understands that frame 1 and frame 2 are received properly.

Sliding Window Protocol

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In sliding window protocol the receiver has to have some memory to compensate any loss in transmission or if the frames are received unordered.

Efficiency of Sliding Window Protocol

η = (W*tx)/(tx+2tp)

W = Window Size

tx = Transmission time

tp = Propagation delay

Sliding window works in full duplex mode

It is of two types:-

1. Selective Repeat: Sender transmits only that frame which is erroneous or is lost.

2. Go back n: Sender transmits all frames present in the window that occurs after the error bit including error bit also.

Sliding Window Protocol Program in C

Below is the simulation of sliding window protocol in C.

Output

Enter window size: 3

Enter number of frames to transmit: 5

Enter 5 frames: 12 5 89 4 6

With sliding window protocol the frames will be sent in the following manner (assuming no corruption of frames)

After sending 3 frames at each stage sender waits for acknowledgement sent by the receiver

12 5 89
Acknowledgement of above frames sent is received by sender

4 6
Acknowledgement of above frames sent is received by sender

Sliding Window Protocol Program in C++

Below is the simulation of sliding window protocol in C++.

Comment below if you have any queries regarding above program.

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