sliding_serv.py

import socket
s=socket.socket(socket.AF_INET,socket.SOCK_STREAM)
s.bind(('127.0.0.1',2231))
s.listen(5)
input=raw_input("enter the data to be transmitted : ")
client,address=s.accept()
print "sending frames to :"+str(address)
window=4
frames=[]
for k in input:
	frames.append(k)
print frames
count=0
while True:
	if len(input)-count>4:
		window=4
	else:
		window=len(input)-count
	if window<=0:
		break
	temp=[]
	for l in range(count,count+window):
		temp.append(str(l))
	client.send(''.join(frames[count:count+window])+' '+' '.join(temp))
	recv=client.recv(1024)
	if(int(recv)==0):
		count+=window
		continue
	else:
		frameno=client.recv(1024)
		frameno=int(frameno)
		print frameno
		client.send(''.join(frames[frameno:count+window])+' '+' '.join(temp[frameno:]))
		count+=window
client.send("exit")
s.close()