WebSocket部署服务器外网无法连接解决方案

<script type="text/javascript">
        $(function () {
            var url = "ws://xxxx:xx"+"@Url.Action("RequestProcessCenter")";
            var ws;
            function connect() {
                ws = new WebSocket(url);
                $("#TopicContent").append("正在连接\n");
                ws.onopen = function () {
                    $("#TopicContent").append("已经连接\n");
                };
                ws.onmessage = function (evt) {
                    console.log(evt.data);
                    $("#TopicContent").append(evt.data);
                };
                ws.onclose = function () {
                    $("#TopicContent").append("已经关闭\n");
                };
                ws.onerror = function (evt) {
                    console.log(evt.data);
                    $("#TopicContent").append(evt.data);
                };
            };
            $("#send").click(function () {
                console.log(1);
                console.log(ws.readyState);
                console.log(WebSocket.OPEN);
                if (ws.readyState == WebSocket.OPEN) {
                    ws.send($("#content").val());
                    $(this).val("");
                }
                else {
                    $("#TextMessge").append("连接已经关闭");
                }
            });
            $("#open").click(function () {
                connect();
            });
            $("#close").click(function () {
                ws.close();
            });
        });
    </script>

public void RequestProcessCenter()
        {
            if (HttpContext.IsWebSocketRequest)
            {
                var currUser = GetCurrUser();
                this._UserName = currUser.LoginName;
                HttpContext.AcceptWebSocketRequest(ProcessTopic);
            }
            else
            {
                HttpContext.Response.Write("请求失败哟");
            }
        }