diff --git a/dist/dhcp/server.js b/dist/dhcp/server.js
index b4700f7..4edcb9a 100644
--- a/dist/dhcp/server.js
+++ b/dist/dhcp/server.js
@@ -32,7 +32,7 @@ Server = (function(superClass) {
 
   function Server(config) {
     var sock, sock6;
-    Server.__super__.constructor.apply(this, arguments);
+    Server.__super__.constructor.call(this);
     sock = dgram.createSocket({
       type: 'udp4',
       reuseAddr: true
diff --git a/dist/http/cwmp/xml.js b/dist/http/cwmp/xml.js
index 1761073..5b9bd0a 100644
--- a/dist/http/cwmp/xml.js
+++ b/dist/http/cwmp/xml.js
@@ -101,7 +101,7 @@ exports.parse = function(xml) {
   );
 };
 
-methods = {
+exports.methods = methods = {
   'cwmp:TransferCompleteResponse': function(res) {
     var h, i, ref, w;
     i = 0;
diff --git a/dist/port.js b/dist/port.js
new file mode 100644
index 0000000..d7f0a3d
--- /dev/null
+++ b/dist/port.js
@@ -0,0 +1,19 @@
+var net;
+
+net = require('net');
+
+module.exports = function() {
+  return new Promise(function(resolve, reject) {
+    var server;
+    server = net.createServer();
+    server.unref();
+    server.on('error', reject);
+    return server.listen(0, function() {
+      var port;
+      port = server.address().port;
+      return server.close(function() {
+        return resolve(port);
+      });
+    });
+  });
+};
diff --git a/package.json b/package.json
index a54d0ea..fd9e02d 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "tch-exploit",
-  "version": "2.0.0-b2",
+  "version": "2.0.0-b3",
   "main": "dist/index.js",
   "bin": "dist/index.js",
   "scripts": {
diff --git a/src/http/cwmp/xml.coffee b/src/http/cwmp/xml.coffee
index b7f10b7..893cda5 100644
--- a/src/http/cwmp/xml.coffee
+++ b/src/http/cwmp/xml.coffee
@@ -92,7 +92,7 @@ exports.parse = (xml) ->
 
   "#{name}": obj
 
-export.methods = methods =
+exports.methods = methods =
 
   'cwmp:TransferCompleteResponse': (res) ->
     i = 0