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Multiplex multiple services through one (TCP) port.


Multiplex multiple services through one (TCP) port.


The muxer basically sniffs the initial data packet sent by the client to determine (using a rule set) where to forward the request to.


Instead of having to expose all your services to the outside world on their respective ports, use a single port to access them all. Initially created to multiplex HTTP, HTTPS and SOCKS5 traffic over one port for a personal project.


From the NPM repository:

$ npm install port-mux

From the Github repository:

$ git clone
$ cd node-port-mux
$ npm install [-g]


var Muxer = require('port-mux');
// instantiate Muxer 
  // match HTTP GET requests (using a prefix string match) and forward them to localhost:80 
  .addRule('GET ', 80)
  // match TLS (HTTPS) requests (versions 3.{0,1,2,3}) using a regular expression 
  .addRule(/^\x16\x03[\x00-\x03]/, '') // regex match 
  // you can also proxy UNIX domain sockets (which should already exist when you call .addRule()): 
  .addRule(..., '/tmp/my-unix-domain-socket')
  // you can also pass a matcher function: 
  .addRule(function(chunk) {
    // - chunk is a Buffer 
    // - if the function returns true, the match is considered a success. 
  }, ...)
  // pass a function as a third argument and it will get called (once the proxy 
  // has connected to the service) using the proxy connection and original 
  // (incoming) connection as arguments: 
  .addRule(..., ..., function(proxy, conn) {
    var addr = proxy.address();
    console.log('Incoming connection from %s passed to %s:%s',
  // start listening on port 3000 

Performance impact

There's going to be a performance impact when using this module, since it's proxying connections to the endpoint.

Using httperf, these are the results I get on a Macbook Pro (using the modified version of the example.js script in the repository):

Type of connection Reqs/s I/O speed Remarks
Direct 9991 1863 KB/s access HTTP server directly (not muxed)
Muxed (TCP) 4881 910 KB/s HTTP server uses TCP sockets
Muxed (UNIX) 5629 1050 KB/s HTTP server uses UNIX domain sockets

So performance impact is about 50%, a bit less when you use UNIX domain sockets.


Simplified BSD License ( BSD-2-Clause ).