RTMFP直接點對點連接在Windows XP上運行，但在Windows 7上運行

Question

我們在這裏遇到了一個項目上的奇怪問題。當我們將NetConnection與NetGroup結合使用以在Windows XP上啓動兩個本地AIR應用程序之間的通信時，它們始終都會成功連接到NetGroup，並將相互檢測爲鄰居。但是，在Windows 7上，兩個應用程序都成功連接到NetConnection，並且NetGroup都不會將相互檢測爲鄰居。

要重現這個問題，這裏有兩個AIR應用程序：

RTMFP1：

<?xml version="1.0" encoding="utf-8"?> 
<s:WindowedApplication xmlns:fx="http://ns.adobe.com/mxml/2009" 
xmlns:s="library://ns.adobe.com/flex/spark" 
xmlns:mx="library://ns.adobe.com/flex/mx" 
applicationComplete="init()"> 
<fx:Declarations> 
    <!-- Place non-visual elements (e.g., services, value objects) here --> 

</fx:Declarations> 
<fx:Script> 
    <![CDATA[ 
     private var nc:NetConnection; 

     private var group:NetGroup; 

     [Bindable] 
     private var connected:Boolean = false; 


     private function init():void 
     { 
      connect(); 
     } 

     private function connect():void 
     { 
      nc = new NetConnection(); 
      nc.addEventListener(NetStatusEvent.NET_STATUS, netStatus); 
      nc.connect("rtmfp:"); 
     } 

     private function netStatus(event:NetStatusEvent):void 
     { 
      writeText(event.info.code); 

      switch (event.info.code) 
      { 
       case "NetConnection.Connect.Success": 
        setupGroup(); 
        break; 

       case "NetGroup.Connect.Success": 
        connected = true; 
        break; 

       case "NetGroup.Posting.Notify": 
        receiveMessage(event.info.message) 
        break; 
      } 
     } 

     private function setupGroup():void 
     { 
      var groupspec:GroupSpecifier = new GroupSpecifier("myGroup/groupOne"); 
      groupspec.postingEnabled = true; 
      groupspec.ipMulticastMemberUpdatesEnabled = true; 
      groupspec.addIPMulticastAddress("127.0.0.1:30302"); 

      group = new NetGroup(nc, groupspec.groupspecWithAuthorizations()); 
      group.addEventListener(NetStatusEvent.NET_STATUS, netStatus); 
     } 

     private var i:int = 0; 

     private function sendMessage():void 
     { 
      var message:Object = new Object(); 
      message.sender = group.convertPeerIDToGroupAddress(nc.nearID); 
      message.text = "Here's your message!"; 
      message.random = i++; 
      group.post(message); 
     } 

     public function receiveMessage(message:Object):void 
     { 
      writeText(message.text); 
     } 

     private function writeText(txt:String):void 
     { 
      txtHistory.text += txt + "\n"; 
     } 


     private function btnSend_clickHandler(event:MouseEvent):void 
     { 
      sendMessage(); 
     } 
    ]]> 
</fx:Script> 
<s:layout> 
    <s:VerticalLayout/> 
</s:layout> 
<s:TextArea id="txtHistory" 
    width="100%" height="100%"/> 
<s:Button id="btnSend" 
    enabled="{connected}" 
    label="Send message" 
    click="btnSend_clickHandler(event)"/> 
</s:WindowedApplication> 

RTMFP2：

<?xml version="1.0" encoding="utf-8"?> 
<s:WindowedApplication xmlns:fx="http://ns.adobe.com/mxml/2009" 
xmlns:s="library://ns.adobe.com/flex/spark" 
xmlns:mx="library://ns.adobe.com/flex/mx" 
applicationComplete="connect()"> 
<fx:Declarations> 
    <!-- Place non-visual elements (e.g., services, value objects) here --> 
</fx:Declarations> 
<fx:Script> 
    <![CDATA[ 
     private var nc:NetConnection; 

     private var group:NetGroup; 

     [Bindable] 
     private var connected:Boolean = false; 


     private function connect():void 
     { 
      nc = new NetConnection(); 
      nc.addEventListener(NetStatusEvent.NET_STATUS, netStatus); 
      nc.connect("rtmfp:"); 

     } 

     private function netStatus(event:NetStatusEvent):void 
     { 
      switch (event.info.code) 
      { 
       case "NetConnection.Connect.Success": 
        setupGroup(); 
        break; 

       case "NetGroup.Connect.Success": 
        connected = true; 
        break; 

       case "NetGroup.Posting.Notify": 
        receiveMessage(event.info.message) 
        break; 
      } 
     } 

     private function setupGroup():void 
     { 
      var groupspec:GroupSpecifier = new GroupSpecifier("myGroup/groupOne"); 
      groupspec.postingEnabled = true; 
      groupspec.ipMulticastMemberUpdatesEnabled = true; 
      groupspec.addIPMulticastAddress("127.0.0.1:30302"); 

      group = new NetGroup(nc, groupspec.groupspecWithAuthorizations()); 
      group.addEventListener(NetStatusEvent.NET_STATUS, netStatus); 
     } 

     private var i:int = 0; 

     private function sendAcknowledge():void 
     { 
      var message:Object = new Object(); 
      message.text = "We received your message!"; 
      message.sender = group.convertPeerIDToGroupAddress(nc.nearID); 
      message.sequence = i++; 
      group.post(message); 
     } 

     public function receiveMessage(message:Object):void 
     { 
      writeText(message.text); 
      sendAcknowledge(); 
     } 

     private function writeText(txt:String):void 
     { 
      textArea.text += txt + "\n"; 
     } 
    ]]> 
</fx:Script> 
<s:layout> 
    <s:VerticalLayout/> 
</s:layout> 
<s:TextArea id="textArea" width="100%" height="100%"/> 
</s:WindowedApplication> 

這些應用程序可以連接併發送消息給對方不會有問題在Windows XP上。但是，在Windows 7上，他們不能。

有誰知道爲什麼這不會在Windows 7上工作，以及可以採取哪些措施使其工作？這對我們的項目至關重要。在某些情況下，應用程序需要相當長的時間才能將相互檢測爲鄰居（某些情況下最多15秒），而在其他情況下，它們會立即檢測到對方。有誰知道什麼可能會導致這種延遲？

Answer 1

我的第一個猜測可能是防火牆或網絡。 RTMFP使用 UDP port 1935這是非標準的，許多企業防火牆阻止所有不是端口80或443（HTTP，HTTPS）的。

這就是爲什麼如果p2p不起作用，建議您有第三方服務器回退，因爲情況並非總是如此。