Question

我们在这个项目上遇到了一个奇怪的问题。当我们将NetConnection与NetGroup结合使用以启动Windows XP上两个本地AIR应用程序之间的通信时，它们总是成功连接到NetGroup并相互检测为邻居。但是，在Windows 7上，两个应用程序连接成功连接到NetConnection和NetGroup都不会将对方检测为邻居。

要重现此问题，以下是两个AIR应用程序：

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>

这些应用程序可以在Windows XP上相互连接和发送消息而不会出现问题。但是，在Windows 7上，它们不能。

有谁知道为什么这不适用于Windows 7以及可以采取哪些步骤来使其工作？这对我们的项目至关重要。

P.s。：在某些情况下，应用程序需要相当长的时间来检测彼此作为邻居（在某些情况下最多15秒），在其他情况下，它们会立即相互检测到。有谁知道什么可能导致这种延迟？

Answer 1

我的第一个猜测是使用防火墙或网络。 RTMFP使用 UDP port 1935是非标准的，许多企业级防火墙阻止了非端口80或443（HTTP，HTTPS）的所有内容。

这就是为什么如果p2p不起作用，建议你有第三方服务器后备，因为情况并非总是如此。

RTMFP直接在Windows XP上进行点对点连接，但不在Windows 7上

1 个答案: