One Bit Sliding Window Protocol

Question - To write a C program to Implement One Bit Sliding Window Protocol.

Screenshot of Output



Program

sender.c (server)

#include "stdio.h"
#include "sys/types.h"
#include "netinet/in.h"
#include "string.h"
#include "sys/socket.h"
#include "stdlib.h"
#include "unistd.h"
main()
{
int sd,i,r,bi,nsd,port,frame,prev_frame=0,count=0;;
char ack[5],buff[30];
struct sockaddr_in ser,cli;
if((sd=socket(AF_INET,SOCK_STREAM,IPPROTO_TCP))==-1)
{
printf("\n Socket problem");
return 0;
}
printf("\n Socket created\n");
bzero((char*)&cli,sizeof(ser));
printf("ENTER PORT NO:\n");
scanf("%d",&port);
printf("\n Port Address is %d\n:",port);
ser.sin_family=AF_INET;
ser.sin_port=htons(port);
ser.sin_addr.s_addr=htonl(INADDR_ANY);

bi=bind(sd,(struct sockaddr *)&ser,sizeof(ser));
if(bi==-1)
{
printf("\n bind error, port busy, plz change port in client and server");
return 0;
}
i=sizeof(cli);
listen(sd,5);
nsd = accept(sd,((struct sockaddr *)&cli),&i);
if(nsd==-1)
{
printf("\ncheck the description parameter\n");
return 0;
}
printf("\nConnection accepted.");
while(count<5)
{
ph:
printf("\nSending FRAME %d to the Receiver...\n",prev_frame); snprintf(buff,sizeof(buff),"%d",prev_frame);
send(nsd,buff,30,0);
r = recv(nsd,ack,5,0);
if(strcmp(ack,"ack")==0 || strcmp(ack,"ACK")==0)
{ count++;
if(prev_frame==0) prev_frame=1;
else prev_frame = 0;
}
else if(strcmp(ack,"nak")==0 || strcmp(ack,"NAK")==0)
{
printf("\n NAK: So again sending the Previous frame...\n"); goto ph;
}
}
printf("\n Bye..");
send(nsd,"EOF",4,0);
close(sd);
close(nsd);
return 0;
}


receiver.c (client)

#include "stdio.h"
#include "sys/types.h"
#include "netinet/in.h"
#include "string.h"
#include "sys/socket.h"
#include "stdlib.h"
#include "unistd.h"
int main()
{
int sd,con,port,i;
char content[30],ack[3];
struct sockaddr_in cli;
if((sd=socket(AF_INET,SOCK_STREAM,IPPROTO_TCP))==-1)
{
printf("\n Socket problem");
return 0;
}
bzero((char*)&cli,sizeof(cli));
cli.sin_family = AF_INET;
printf("ENTER PORT NO");
scanf("%d",&port);
cli.sin_port=htons(port);
cli.sin_addr.s_addr=htonl(INADDR_ANY);
con=connect(sd,(struct sockaddr*)&cli,sizeof(cli));
if(con==-1)
{
printf("\n connection error");
return 0;
}
i=recv(sd,content,30,0);
while(strcmp(content,"EOF") != 0)
{
printf("Received from Sender: Frame %s \n",content);
ph:
printf("\n Acknowledgement(ACK/NAK) : ");
scanf("%s",ack);
if(!(strcmp(ack,"ack")==0 || strcmp(ack,"nak")==0 || strcmp(ack,"ACK")==0 || strcmp(ack,"NAK")==0))
{
printf("\n Not a valid Acknowledgement..use ACK or NAK..\n ");
goto ph;
}
send(sd,ack,5,0);
i=recv(sd,content,30,0);
}
printf("\n\n Bye...");
close(sd);
return 0;
}

Download Source Codes

sender.c

receiver.c


Program Written by G.Vivek Venkatesh