Networking Lab

 AIM. Write a program to Simulate Packet Transmission Delay

Source code 

packets = {'Packet1', 'Packet2', 'Packet3'}; 

delay = 1; % seconds 

for i = 1:length(packets) 

    fprintf('Transmitting %s...\n', packets{i}); 

    pause(delay); 

end 

AIM. Write a program to check the simple IP Address Validator  

 Source code 

ip = '192.168.1.10'; 

parts = str2double(strsplit(ip, '.')); 

if length(parts)==4 && all(parts >= 0 & parts <= 255) 

    disp('Valid IP Address'); 

else 

    disp('Invalid IP Address'); 

end

AIM. Write a program to simulate Ping with Random Delay.

Source code 

for i = 1:5 
    delay = rand() * 0.1;  % Simulate delay in seconds 
    fprintf('Ping %d: delay = %.2f ms\n', i, delay*1000); 
    pause(1); 
end 

AIM: Write a program to implement a basic Port Scanner (on local host)   

         Source code 

host = '127.0.0.1'; 
for port = 80:85 
    try 
        t = tcpclient(host, port, 'Timeout', 0.5); 
        fprintf('Port %d is open\n', port); 
        clear t 
catch 
        fprintf('Port %d is closed\n', port); 
    end 
end

AIM. Write a program to design a TCP/IP Client server model to transmit the data with delay.

 Source code 

% Server (Receiver) 

server = tcpserver("127.0.0.1", 30000);
disp('Server is listening...'); 
while true 
    if server.NumBytesAvailable > 0 
        data = read(server, server.NumBytesAvailable, "string"); 
        disp(['Received: ', data]); 
    end 
    pause(0.1);  % small delay to avoid busy waiting 
end 

Run below first: 

% Client (Transmitter) 

client = tcpclient("127.0.0.1", 30000);  % Connect to server at localhost, port 30000 
disp('Client connected to server'); 
messages = ["Hello", "This is test data", "With latency", "Goodbye"]; 
latency = 2;  % Latency in seconds between packets 
for i = 1:length(messages) 
    write(client, messages(i), "string"); 
    disp(['Sent: ', messages(i)]); 
    pause(latency);  % simulate delay 
end 

Stop-and-wait

clc;
clear;
for i = 1:5
    fprintf("Sending Frame %d...\n", i);
    if rand < 0.3
        disp("ACK Lost! Retransmitting the same frame...");
        i = i - 1;   
    else
        disp("ACK Received.");
    end
    pause(0.5);   
end
disp("All frames are sent successfully!");

Go-BACK-NARQ

clc;

clear;

n = 4;          

total = 10;    

for i = 1:total

    if rand < 0.25

        fprintf("Frame %d lost!\n", i);

    else

        fprintf("Frame %d sent successfully.\n", i);

    end

    if mod(i, n) == 0

        disp("---- Moving to Next Window ----");

        pause(0.5);  % Small delay for simulation

    end

end

disp("Transmission complete!");