SIMULATON OF SLIDING WINDOW PROTOCOL

SERVER SIDE:

#include<stdio.h>

#include<sys/types.h>

#include<sys/socket.h>

#include<netinet/in.h>

#include<string.h>

int main(int argc,char **argv)

{

int len;

int listenfd,connfd,n;

struct sockaddr_in servaddr,cliaddr;

char b[1024];

char c[1000];

listenfd=socket(AF_INET,SOCK_STREAM,0);

if(listenfd<0)

perror("cannot create socket");

bzero(&servaddr,sizeof(servaddr));

servaddr.sin_family=AF_INET;

servaddr.sin_addr.s_addr=inet_addr("20.30.1.211");

servaddr.sin_port=htons(20064);

bind(listenfd,(struct sockaddr*)&servaddr,sizeof(servaddr));

listen(listenfd,5);

len=sizeof(cliaddr);

connfd=accept(listenfd,(struct sockaddr*)&cliaddr,&len);

if(connfd>0)

printf("\n connection established");

do

{

n=read(connfd,b,1024);

printf("\n reeive data %s",b);

printf("\n your acknowledgement[yes=1,no=0]:");

scanf("%s",c);

n=write(connfd,c,1024);

}while(1);

close(connfd);

close(listenfd);

return 0;

}

CLIENT SIDE:

#include<stdio.h>

#include<sys/types.h>

#include<sys/socket.h>

#include<netinet/in.h>

#include<string.h>

int main(int arg,char **argv)

{

int len;

int sockfd,n,m,p;

struct sockaddr_in servaddr,cliaddr;

char buff[1024];

char buff1[1000];

char str[1000];

char d[10]={'a','b','c','d','e','f','g','h','i','j'};

int count[10],ack[10];

int i,j,k;

for(k=0;k<10;k++)

{

count[k]=0;

ack[k]=0;

}

sockfd=socket(AF_INET,SOCK_STREAM,0);

if(sockfd<0)

perror("\n cannot create socket");

bzero(&servaddr,sizeof(servaddr));

servaddr.sin_family=AF_INET;

servaddr.sin_addr.s_addr=inet_addr("20.30.1.211");

servaddr.sin_port=htons(20064);

m=connect(sockfd,(struct sockaddr *)&servaddr,sizeof(servaddr));

if(m==0)

printf("\n connection established");

i=0;

do

{

 *buff=d[i];

n=write(sockfd,buff,1024);

n=read(sockfd,buff1,1024);

if(strcmp(buff1,"1")==0)

{

for(p=i;p>i-2,p>=0;p--)

{

ack[p]=1;

count[p]=1;

}

}

for(j=i;j>i-3,j>=0;j--)

{

if(ack[j]==0)

count[j]++;

}

if(i>=2 && count[i-2]==3)

{

count[i-2]=1;

i=i-2;

}

else

i++;

}

while(i<10);

printf("the data is successfully sent to the server \n");

close(sockfd);

return 0;

}

OUTPUT:

SERVER SIDE:

"serversli.c" 39L, 881C written

[ME04@TELNET ~]$ cc serversli.c

[ME04@TELNET ~]$ ./a.out

 connection established

 reeive data a

 your acknowledgement[yes=1,no=0]:1

 reeive data b

 your acknowledgement[yes=1,no=0]:1

 reeive data c

 your acknowledgement[yes=1,no=0]:1

 reeive data d

 your acknowledgement[yes=1,no=0]:1

 reeive data e

 your acknowledgement[yes=1,no=0]:1

 reeive data f

 your acknowledgement[yes=1,no=0]:1

 reeive data g

 your acknowledgement[yes=1,no=0]:1

 reeive data h

 your acknowledgement[yes=1,no=0]:1

 reeive data i

 your acknowledgement[yes=1,no=0]:0

 reeive data j

 your acknowledgement[yes=1,no=0]:1

 reeive data j

 your acknowledgement[yes=1,no=0]:1

 reeive data j

 your acknowledgement[yes=1,no=0]:0

[ME04@TELNET ~]$

CLIENT SIDE:

"clientsli.c" 64L, 1100C written

[ME04@TELNET ~]$ cc clientsli.c

[ME04@TELNET ~]$ ./a.out

 connection establishedthe data is successfully sent to the server

[ME04@TELNET ~]$