Oh - sorry - you're *not* just talking about protocol... :)

IO::Socket is the OO version of the basic 'Socket' module - you can use either, though it's usually easier to use the first to do something like below...

A client...

use IO::Socket::INET;
my $socket = IO::Socket::INET->new("${my_server}:${my_port}") or die $
+!;
print $socket "My Ping\n";
my $answer = <$socket>; #should be 'My Pong'
close $socket;
[download]

A server...

use IO::Socket::INET;
my $server = IO::Socket::INET->new(LocalPort=>$my_port,Type=>SOCK_STRE
+AM,Listen=>1) or die $!;
while (my $client = $server->accept()) {
    my $message = <$client>;
    print $client "My Pong\n" if ($message =~/My Ping/);
}
[download]

...which is obviously not going anywhere near production code, but should be enough to get started with. Check out the 'Sockets' section of the Camel Book for more info.

Cheers, Ben.