title: What about WAMP.2?
body: <p>It seems to be really hard to find anything about the WAMP.2 protocol. I am trying to connect to a webSocket that uses WAMP.2, using Python, autobahn and twisted. However, I keep getting this error: </p>
  
  <pre><code>2018-03-09 14:54:53+0100 [-] Log opened.
  2018-03-09 14:54:53+0100 [-] Starting factory 
  &lt;autobahn.twisted.websocket.WebSocketClientFactory object at 0x000002A461F489B0&gt;
  2018-03-09 14:54:53+0100 [-] failing WebSocket opening handshake ('WebSocket connection upgrade failed (400 -ThisserveronlyspeaksWebSocketsubprotocolswamp.2.cbor.batched,wamp.2.cbor,wamp.2.msgpack.batched,wamp.2.msgpack,wamp.2.ubjson.batched,wamp.2.ubjson,wamp.2.json.batched,wamp.2.json)')
  2018-03-09 14:54:53+0100 [-] dropping connection to peer tcp4:... with abort=True: WebSocket connection upgrade failed (400 - ThisserveronlyspeaksWebSocketsubprotocolswamp.2.cbor.batched,wamp.2.cbor,wamp.2.msgpack.batched,wamp.2.msgpack,wamp.2.ubjson.batched,wamp.2.ubjson,wamp.2.json.batched,wamp.2.json)
  2018-03-09 14:54:53+0100 [-] Stopping factory 
  &lt;autobahn.twisted.websocket.WebSocketClientFactory object at 0x000002A461F489B0&gt;
  2018-03-09 14:55:01+0100 [-] Received SIGINT, shutting down.
  2018-03-09 14:55:01+0100 [-] Main loop terminated.
  </code></pre>
  
  <p>Now, usually, when I get stuck I can find at least something about it on the internet. However, there seems to be little to no information about this (google doesn't even give any results relating WAMP.2).</p>
  
  <p>I imagine that if webSocket servers are using WAMP.2 there must be a way to connect to them, right? If so, why is it so hard to find anything about it?</p>
  
  <p>The code I am working with:</p>
  
  <pre><code>from autobahn.twisted.websocket import WebSocketClientFactory, 
  WebSocketClientProtocol, connectWS
  from twisted.internet import reactor
  
  class EchoClientProtocol(WebSocketClientProtocol):
  
      def sendHello(self):
          self.sendMessage("Hello, world!")
  
      def onOpen(self):
          self.sendMessage("Hi there")
  
      def onMessage(self, msg, binary):
          print("Got echo: " + msg)
          reactor.callLater(1, self.sendHello)
  
  if __name__ == '__main__':
  
      import sys
  
      from twisted.python import log
  
      log.startLogging(sys.stdout)
      factory = WebSocketClientFactory("wss://api.poloniex.com")
      factory.protocol = EchoClientProtocol
      connectWS(factory)
      reactor.run()
  </code></pre>