This is the server socket's didAcceptNewSocket delegate method.

SocketServerDelegate.m

// GCDAsyncSocket delegate, called when the server (device receiving JSON) accepts an incoming client connection.  another socket is spawned to handle it.
- (void)socket:(GCDAsyncSocket *)sender didAcceptNewSocket:(GCDAsyncSocket *)newSocket
{
    // The "sender" parameter is the listenSocket we created.
    // The "newSocket" is a new instance of GCDAsyncSocket.
    // It represents the accepted incoming client connection.

    // Do server stuff with newSocket...
    NSLog(@"Accepted new socket from %@:%hu", [newSocket connectedHost], [newSocket connectedPort]);

    NSString *welcomMessage = @"Server says Hi, send me some JSON \r\n";
    [newSocket writeData:[welcomMessage dataUsingEncoding:NSUTF8StringEncoding] withTimeout:-1 tag:TAG_ASK_FOR_JSON];
}