Trying to make basic connection.

I'm trying to connect two machines together. I know that I can't just connect immediately without doing some testing beforehand, like for NAT. I got this script from the Unity documentation. I think it's supposed to determine if useNAT should be on or off, but some parts look a little messed up to me.

1) The line that says "case ConnectionTesterStatus.NATpunchthroughAddressRestrictedCone:" executes no code.
2) There are 2 cases that say "ConnectionTesterStatus.LimitedNATPunchthroughPortRestricted:"

As of right now I am unable to establish a connection with this script. Can someone update it?

Also I'm wondering if useNAT is the only thing I need to worry about to guarantee a connection. What are all the variables I need to consider? Because I know that some connections (like 3G) can't initialize a server, right?

Code (csharp):

1. var testStatus = "Testing network connection capabilities.";
2. var testMessage = "Test in progress";
3. var shouldEnableNatMessage : String = "";
4. var doneTesting = false;
5. var probingPublicIP = false;
6. var serverPort = 9999;
7. var connectionTestResult = ConnectionTesterStatus.Undetermined;
8.  
9. // Indicates if the useNat parameter be enabled when starting a server
10. var useNat = false;
11.  
12. function OnGUI() {
13.     GUILayout.Label("Current Status: " + testStatus);
14.     GUILayout.Label("Test result : " + testMessage);
15.     GUILayout.Label(shouldEnableNatMessage);
16.     if (!doneTesting)
17.         TestConnection();
18. }
19.  
20. function TestConnection() {
21.     // Start/Poll the connection test, report the results in a label and
22.     // react to the results accordingly
23.     connectionTestResult = Network.TestConnection();
24.     switch (connectionTestResult) {
25.         case ConnectionTesterStatus.Error:
26.             testMessage = "Problem determining NAT capabilities";
27.             doneTesting = true;
28.             break;
29.            
30.         case ConnectionTesterStatus.Undetermined:
31.             testMessage = "Undetermined NAT capabilities";
32.             doneTesting = false;
33.             break;
34.                        
35.         case ConnectionTesterStatus.PublicIPIsConnectable:
36.             testMessage = "Directly connectable public IP address.";
37.             useNat = false;
38.             doneTesting = true;
39.             break;
40.            
41.         // This case is a bit special as we now need to check if we can
42.         // circumvent the blocking by using NAT punchthrough
43.         case ConnectionTesterStatus.PublicIPPortBlocked:
44.             testMessage = "Non-connectble public IP address (port " +
45.                 serverPort +" blocked), running a server is impossible.";
46.             useNat = false;
47.             // If no NAT punchthrough test has been performed on this public
48.             // IP, force a test
49.             if (!probingPublicIP) {
50.                 connectionTestResult = Network.TestConnectionNAT();
51.                 probingPublicIP = true;
52.                 testStatus = "Testing if blocked public IP can be circumvented";
53.                 timer = Time.time + 10;
54.             }
55.             // NAT punchthrough test was performed but we still get blocked
56.             else if (Time.time > timer) {
57.                 probingPublicIP = false;         // reset
58.                 useNat = true;
59.                 doneTesting = true;
60.             }
61.             break;
62.         case ConnectionTesterStatus.PublicIPNoServerStarted:
63.             testMessage = "Public IP address but server not initialized, "+
64.                 "it must be started to check server accessibility. Restart "+
65.                 "connection test when ready.";
66.             break;
67.            
68.         case ConnectionTesterStatus.LimitedNATPunchthroughPortRestricted:
69.             testMessage = "Limited NAT punchthrough capabilities. Cannot "+
70.                 "connect to all types of NAT servers.";
71.             useNat = true;
72.             doneTesting = true;
73.             break;
74.        
75.         case ConnectionTesterStatus.LimitedNATPunchthroughPortRestricted:
76.             testMessage = "Limited NAT punchthrough capabilities. Cannot "+
77.                 "connect to all types of NAT servers. Running a server "+
78.                 "is ill advised as not everyone can connect.";
79.             useNat = true;
80.             doneTesting = true;
81.             break;
82.            
83.         case ConnectionTesterStatus.LimitedNATPunchthroughSymmetric:
84.             testMessage = "Limited NAT punchthrough capabilities. Cannot "+
85.                 "connect to all types of NAT servers. Running a server "+
86.                 "is ill advised as not everyone can connect.";
87.             useNat = true;
88.             doneTesting = true;
89.             break;
90.        
91.         case ConnectionTesterStatus.NATpunchthroughAddressRestrictedCone:
92.         case ConnectionTesterStatus.NATpunchthroughFullCone:
93.             testMessage = "NAT punchthrough capable. Can connect to all "+
94.                 "servers and receive connections from all clients. Enabling "+
95.                 "NAT punchthrough functionality.";
96.             useNat = true;
97.             doneTesting = true;
98.             break;
99.  
100.         default:
101.             testMessage = "Error in test routine, got " + connectionTestResult;
102.     }
103.     if (doneTesting) {
104.         if (useNat)
105.             shouldEnableNatMessage = "When starting a server the NAT "+
106.                 "punchthrough feature should be enabled (useNat parameter)";
107.         else
108.             shouldEnableNatMessage = "NAT punchthrough not needed";
109.         testStatus = "Done testing";
110.     }
111. }