Trying to Connect a Remote Computer from a Different ISP

Hi! I have been struggling with network connectivity with another user. I can host the server over my LAN and it works fine, but whenever I try to connect a computer from a different ISP, it will not allow them to connect. They can see my server on a different script I wrote that shows up in a list, but cannot connect (You tell the game to refresh the server list and it brings up any servers it finds). I have port-forwarded port 80 and verified that it is open with CanYouSeeMe.org. Please help and thank you for reading this. :) Here is my code for Multiplayer Management.

 using UnityEngine;
 using System.Collections;
 
 /// <summary>
 /// This script is attached to the MultiplayerManager and it
 /// is the foundation for our multiplayer system.
 /// </summary>
 
 public class MultiplayerScript : MonoBehaviour 
 {
     //Variables Start===================================
     
     private string titleMessage = "Network Prototype";
     
     private string connectToIP  = "127.0.0.1";
     
     private int connectionPort  = 80;
     
     private bool useNAT = false;
     
     private string ipAddress;
     
     private string port;
     
     private int numberOfPlayers = 10;
     
     public string playerName;
     
     public string serverName;
     
     public string serverNameForClient;
     
     private bool iWantToSetupAServer = false;
     
     private bool iWantToConnectToAServer = false;
     
     
     // These variables are used to define the main window.
     
     private Rect connectionWindowRect;
     
     private int connectionWindowWidth = 400;
     
     private int connectionWindowHeight = 280;
     
     private int buttonHeight = 60;
     
     private int leftIndent;
     
     private int topIndent;
     
     
     //These variables are used to define the server
     //shutdown window.
     
     private Rect serverDisWindowRect;
     
     private int serverDisWindowWidth = 300;
     
     private int serverDisWindowHeight = 150;
     
     private int serverDisWindowLeftIndent = 10;
     
     private int serverDisWindowTopIndent = 10;
     
     
     //These variables are used to define the client
     //disconnect window.
     
     private Rect clientDisWindowRect;
     
     private int clientDisWindowWidth = 300;
     
     private int clientDisWindowHeight = 170;
     
     private bool showDisconnectWindow = false;
     
     // Variables End=====================================
 
     // Use this for initialization
     void Start () 
     {
         //Load the last used serverName from registry.
         //If the serverName is blank then use "Server"
         //as a default name.
         
         serverName = PlayerPrefs.GetString("serverName");
         
         if(serverName == "")
         {
             serverName = "Server";    
         }
         
         //Load the last used playerName from registry.
         //If the playerName is blank the use "Player"
         //as a default name.
         
         playerName = PlayerPrefs.GetString("playerName");
         
         if(playerName == "")
         {
             playerName = "Player";
         }
     }
     
     // Update is called once per frame
     void Update () 
     {
         if(Input.GetKeyDown(KeyCode.Escape))
         {
             showDisconnectWindow = !showDisconnectWindow;    
         }
     }
     
     void ConnectWindow(int windowID)
     {
         //Leave a gap from the header.
         
         GUILayout.Space(15);
         
         //When the player launches the game they have the option
         //to create a server or join a server. The variables
         //iWantToSetupAServer and iWantToConnectToAServer start as
         //false so that the player is presented with two buttons
         //"Setup my server" and "Connect to a server".
         
         if(iWantToSetupAServer == false && iWantToConnectToAServer == false)
         {
             if(GUILayout.Button("Setup a server", GUILayout.Height(buttonHeight)))
             {
                 iWantToSetupAServer = true;    
             }
             
             GUILayout.Space(10);
             
             if(GUILayout.Button("Connect to a server", GUILayout.Height(buttonHeight)))
             {
                 iWantToConnectToAServer = true;    
             }
             
             GUILayout.Space(10);
             
             if(Application.isWebPlayer == false && Application.isEditor == false)
             {
                 if(GUILayout.Button("Exit Prototype", GUILayout.Height(buttonHeight)))
                 {
                     Application.Quit();    
                 }
             }
         }
         
         if(iWantToSetupAServer == true)
         {
             //The user can type a name for their server into the
             //textfield.
             
             GUILayout.Label("Enter a name for your server");
             
             serverName = GUILayout.TextField(serverName);
             
             GUILayout.Space(5);
             
             //The user can type in the port number for their server
             //into the textfield. We defined the default value above in
             //the 26500.
             
             GUILayout.Label("Server Port");
             
             connectionPort = int.Parse(GUILayout.TextField(connectionPort.ToString()));
             
             GUILayout.Space(10);
             
             if(GUILayout.Button("Start my own server", GUILayout.Height(30)))
             {
                 //Create the server.
                 
                 Network.InitializeServer(numberOfPlayers, connectionPort, useNAT);
                 
                 //Save the serverName using PlayerPrefs.
                 
                 PlayerPrefs.SetString("serverName", serverName);
                 
                 iWantToSetupAServer = false;
             }
             
             if(GUILayout.Button("Go Back", GUILayout.Height(30)))
             {
                 iWantToSetupAServer = false;    
             }
         }
         
         if(iWantToConnectToAServer == true)
         {
             //The user can type their player name into the
             //textfield.
             
             GUILayout.Label("Enter your player name");
             
             playerName = GUILayout.TextField(playerName);
             
             GUILayout.Space(5);
             
             //The player can type the IP address for the server
             //that they want to connect to into the textfield.
             
             GUILayout.Label("Type in Server IP");
             
             connectToIP = GUILayout.TextField(connectToIP);
             
             GUILayout.Space(5);
             
             //The player can type in the Port number for the server
             //they want to connect to into the textfield.
             
             GUILayout.Label("Server Port");
             
             connectionPort = int.Parse(GUILayout.TextField(connectionPort.ToString()));
             
             GUILayout.Space(5);
             
             //The player clicks on this button to establish a connection.
             
             if(GUILayout.Button("Connect", GUILayout.Height(25)))
             {
                 //Ensure that the play can't join a game with an empty name.
                 
                 if(playerName == "")
                 {
                     playerName = "Player";    
                 }
                 
                 //If the player has a name that isn't empty then attempt to join
                 //the server.
                 
                 if(playerName != "")
                 {
                     //Connect to a server with the IP address contained in
                     //connectToIP and with the port number contained in
                     //connectionPort.
                     
                     Network.Connect(connectToIP, connectionPort);
                     
                     PlayerPrefs.SetString("playerName", playerName);
                 }
             }
             
             GUILayout.Space(5);
             
             if(GUILayout.Button("Go Back", GUILayout.Height(25)))
             {
                 iWantToConnectToAServer = false;    
             }
         }
     }
     
     void ServerDisconnectWindow(int windowID)
     {
         GUILayout.Label("Server name: " + serverName);
         
         //Show the number of players connected.
         
         GUILayout.Label("Number of players connected: " + Network.connections.Length);
         
         //If there is at least one connection then show the average ping.
         
         if(Network.connections.Length >= 1)
         {
             GUILayout.Label("Ping: " + Network.GetAveragePing(Network.connections[0]));    
         }
         
         //Shutdown the server if the user clicks on the Shutdown server button.
         
         if(GUILayout.Button("Shutdown server"))
         {
             Network.Disconnect();    
         }
     }
     
     void ClientDisconnectWindow(int windowID)
     {
         //Show the player the server they are connected to and the
         //average ping of their connection.
         
         GUILayout.Label("Connected to server: " + serverName);
         
         GUILayout.Label("Ping: " + Network.GetAveragePing(Network.connections[0]));
         
         GUILayout.Space(7);
         
         //The player disconnects from the server when they press the
         //Disconnect button.
         
         if(GUILayout.Button("Disconnect", GUILayout.Height(25)))
         {
             Network.Disconnect();    
         }
         
         GUILayout.Space(5);
         
         //This button allows the player using a webplayer who has gone
         //fullscreen to be able to return to the game. Pressing escape in
         //fullscreen doesn't help as that just exits fullscreen.
         
         if(GUILayout.Button("Return to Game", GUILayout.Height(25)))
         {
             showDisconnectWindow = false;    
         }
     }
     
     void OnDisconnectedFromServer()
     {
         //If a player loses the connection or leaves the scene
         //then the level is restarted on their computer.
         
         Application.LoadLevel(Application.loadedLevel);
     }
     
     void OnPlayerDisconnected(NetworkPlayer networkPlayer)
     {
         //When the player leaves the server delete them across the network
         //along with their RPCs so that other players no longer see them.
         
         Network.RemoveRPCs(networkPlayer);
         
         Network.DestroyPlayerObjects(networkPlayer);
     }
     
     void OnPlayerConnected(NetworkPlayer networkPlayer)
     {
         networkView.RPC("TellPlayerServerName", networkPlayer, serverName);    
     }
     
     void OnGUI()
     {
         //If the player is disconnected then run the ConnectWindow function.
         
         if(Network.peerType == NetworkPeerType.Disconnected)
         {
             //Determine the position of the window based on the width and
             //height of the screen. The window will be placed in the middle
             //of the screen.
             
             leftIndent = Screen.width / 2 - connectionWindowWidth / 2;
             
             topIndent = Screen.height / 2 - connectionWindowHeight / 2;
             
             connectionWindowRect = new Rect(leftIndent, topIndent, connectionWindowWidth, 
                                             connectionWindowHeight);
             
             connectionWindowRect = GUILayout.Window(0, connectionWindowRect, ConnectWindow,
                                             titleMessage);
         }
         
         //If the game is running as a server then run the ServerDisconnectWindow
         //function.
         
         if(Network.peerType == NetworkPeerType.Server)
         {
             //Defining the Rect for the server's disconnect window.
             
             serverDisWindowRect = new Rect(serverDisWindowLeftIndent, serverDisWindowTopIndent,
                                             serverDisWindowWidth, serverDisWindowHeight);
             
             serverDisWindowRect = GUILayout.Window(1, serverDisWindowRect, ServerDisconnectWindow, "");
         }
         
         //If the connection type is a client (a player) then show a window that allows
         //them to disconnect from the server.
         
         if(Network.peerType == NetworkPeerType.Client && showDisconnectWindow == true)
         {
             clientDisWindowRect = new Rect(Screen.width / 2 - clientDisWindowWidth / 2, 
                                             Screen.height / 2 - clientDisWindowHeight / 2,
                                             clientDisWindowWidth, clientDisWindowHeight);
             
             clientDisWindowRect = GUILayout.Window(1, clientDisWindowRect, ClientDisconnectWindow, "");
         }
     }
     
     //Used to tell the MultiplayerScript in connected players the serverName. Otherwise
     //players connecting wouldn't be able to see the name of the server.
     
     [RPC]
     void TellPlayerServerName (string servername)
     {
         serverName = servername;    
     }
 }