= TCP Communication =


<<TableOfContents>>

See also: [[UdpCommunication|UdpCommunication]]


== Client ==


Here's simple code to send and receive data by TCP in Python:







{{{#!python
#!/usr/bin/env python

import socket


TCP_IP = '127.0.0.1'
TCP_PORT = 5005
BUFFER_SIZE = 1024
MESSAGE = "Hello, World!"

s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect((TCP_IP, TCP_PORT))
s.send(MESSAGE)
data = s.recv(BUFFER_SIZE)
s.close()

print "received data:", data
}}}



== Server ==


Here's simple code to serve TCP in Python:







{{{#!python
#!/usr/bin/env python

import socket


TCP_IP = '127.0.0.1'
TCP_PORT = 5005
BUFFER_SIZE = 20  # Normally 1024, but we want fast response

s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.bind((TCP_IP, TCP_PORT))
s.listen(1)

conn, addr = s.accept()
print 'Connection address:', addr
while 1:
    data = conn.recv(BUFFER_SIZE)
    if not data: break
    print "received data:", data
    conn.send(data)  # echo
conn.close()
}}}



== Links ==


 * [[http://www.python.org/doc/current/lib/module-socket.html|socket]] -- builtin Python module
 * [[http://www.python.org/doc/current/lib/module-telnetlib.html|telnetlib]] -- builtin Python module
 * [[http://woozle.org/~neale/papers/sockets.html|Introduction to TCP Sockets]] -- uses Python to explain. Note: substitute socket.AF_INET where socket.PF_INET is mentioned.


= Discussion =


 . (none yet!)