TCP_DoubleAdapter.js

var net = require('net');

var serverA = net.createServer();
var serverB = net.createServer();

serverA.on('connection', (socketA) => {

	socketA.on('data', (data) => {
		console.log('CLIENTA:', data);
	});

	serverB.on('connection', (socketB) => {

		socketB.on('data', (data) => {
			console.log('CLIENTB:', data);
		});

		socketA.pipe(socketB);
		socketB.pipe(socketA);

	});

});

PORTA = 50100
PORTB = 50101

serverA.listen(PORTA);
serverB.listen(PORTB);

Example: Open up three terminals and type the following commands:
Terminal 1: node TCP_DoubleAdapter.js
Terminal 2: nc 50100
Terminal 3: nc 50101

Then use either instance of netcat to create some network traffic, notice that it is being logged as raw bytes (or a Buffer() object) in the node-js application