Go back N Protocol [Matlab code]

clc;

clear all;

n=input('Number Of Frames: ');

w=input('Window Size: ');

pt=1;

flag=0;

flag2=0;

a=1:n;

while flag==0

if flag2==0

%Transmitting The Frames In A Window

for i=1:w

fprintf('Frame %d Transmitted\n',a(pt));

pt=pt+1;

end

flag2=1;

end

s=randint(1,1,10);

if s>3

fprintf('PAK of Frame %d Received\n',a(pt-w));

fprintf('Frame %d Transmitted\n',a(pt));

if a(pt)==n

flag=1;

end

pt=pt+1;

else

fprintf('NAK Of Frame %d Received\n',a(pt-w));

for j=0:w-1

fprintf('Frame %d Discarded\n',a(pt-w+j));

end

pt=pt-w;

flag2=0;

end

end

%Last 'W' Frames are dealt seperately

i=n-w+1;

while (i<=n)

s=randint(1,1,10);

if s>4

fprintf('PAK of Frame %d Received\n',a(i));

i=i+1;

else

fprintf('NAK of Frame %d Received \n',a(i));

for j=i:n

fprintf('Frame %d Discarded\n',a(j));

end

for k=i:n

fprintf('Frame %d Transmitted\n',a(k));

end

end

end

Distance Vector Routing [Matlab]

clc;

clear all;

ack=0;

s=input('Enter the source router no: ');

z=input('Enter the destination node: ');

while ack==0

%delay routing tables for 5 modes

A=randint(1,5,100);%metric may be delay or no of hops

B=randint(1,5,100);

C=randint(1,5,100);

D=randint(1,5,100);

E=randint(1,5,100);

A(1)=0;B(2)=0;C(3)=0;D(4)=0;E(5)=0;

r=vertcat(A,B,C,D,E);

disp('All routers are updated with routing tables of neighbouring routers');

fprintf('The routing tables for router %d is \n',s);

disp(r);

d(1,5)=0;

count=1;

for i=s

for j=1:5

if j~=i

for k=1:5

if k~=j && k~=i

for l = 1:5

if l~=k && l~=j && l~=i

for m = 1:5

if m~=k && m~=j && m~=i && m~=l

if(m==z)

d(count,:)=[i,j,k,l,m];

count=count+1;

end

end

end

end

end

end

end

end

end

end

count1 =1;

for i=s

for j=1:5

if j~=i

for k=1:5

if k~=j && k~=i

for l=1:5

if l~=k && l~=j && l~=i

if l==z

c(count1,:)=[i,j,k,l];

count1= count1+1;

end

end

end

end

end

end

end

end

count2 = 1;

for i=s

for j=1:5

if j~=i

for k=1:5

if k~=j && k~=i

if k==z

e(count2,:) = [i,j,k,0];

count2= count2 + 1;

end

end

end

end

end

end

%finding the total delay of all possible paths

for i=1:6

del(i)=0;

for j=2:5

del(i)=del(i)+r(d(i,j-1),d(i,j));

end

end

count=i+1;

for i=1:6

del(count)=0;

for j=2:4

del(count)=del(count)+r(c(i,j-1),c(i,j));

end

count=count+1;

end

for i=1:3

del(count)=0;

for j=2:3

del(count)=del(count)+r(e(i,j-1),e(i,j));

end

count=count+1;

end

del(count)=r(s,z);

dc= sort(del);

%possible paths and latest delay paths

fprintf('Possble path delayS');

for i=1:count

for j=1:count

if dc(i)==del(j)

n(i)=j;

if j<=6

fprintf('\n%d %d %d %d %d %d %d',d(j,:),dc(i));

ma(i,:)=cellstr(num2str(d(j,:)));

elseif j<=12

fprintf('\n%d %d %d %d %d',c(j-6),dc(i));

ma(i,:)=cellstr(num2str(c(j-6)));

elseif j<=15

fprintf('\n%d %d %d %d',e((j-12),:),dc(i));

ma(i,:)=cellstr(num2str(e((j-12),:)));

elseif j==16

fprintf('\n%d %d %d',s,z,dc(i));

ma(i,:)=cellstr(num2str([s z]));

end

end

end

end

temp=dc(1);

for i=2:count

if(dc(i)<=temp)

temp=dc(i);

end

end

for i=1:count

if(dc(i)==temp)

break;

end

end

disp(sprintf('\n\n\t Least delay path is %s delay=%d',(char(ma(i))),dc(i)));

m(16,5)=0;

e=char(ma);

for i=1:length(ma)

m(i,1)=str2double(cellstr(e(i,1)));

m(i,2)=str2double(cellstr(e(i,4)));

m(i,3)=str2double(cellstr(e(i,7)));

m(i,4)=str2double(cellstr(e(i,10)));

m(i,5)=str2double(cellstr(e(i,13)));

end

k=m(1,2);

disp(sprintf('Packet sent to %d router',k));

disp('Updating the routing table..');

if (m(1,1)==s&&m(1,2)==z)

ack=1;

disp(sprintf('Packet sent to the destination router %d',z));

end

s=m(1,2);

z=m(1,3);

end

Bit stuffing in data frames[Matlab code]

clc;

clear all;

msg=input('Input Message Binary Bit Stream: ');

count=0;

stuffcount=0;

[M N]=size(msg);

for j=1:N-5+stuffcount

for i=j:j+5

if msg(i)==1

count=count+1;

else

count=0;

break;

end

end

if count==6

msg=[msg(1:j+4) 0 msg(j+5:end)];

count=0;

stuffcount=stuffcount+1;

end

end

fprintf('Stream after the bit is stuffed:');

disp(msg);