开源项目地址：http://dotras.codeplex.com/
使用这个可以方便的操作ADSL拨号、断开。有详细的开发文档，需要的可以自己去看。。
/// <summary>/// 创建或更新一个PPPOE连接(指定PPPOE名称)/// </summary>void CreateOrUpdatePPPOE(string updatePPPOEname){RasDialer dialer = new RasDialer();RasPhoneBook allUsersPhoneBook = new RasPhoneBook();string path = RasPhoneBook.GetPhoneBookPath(RasPhoneBookType.AllUsers);allUsersPhoneBook.Open(path);// 如果已经该名称的PPPOE已经存在，则更新这个PPPOE服务器地址if (allUsersPhoneBook.Entries.Contains(updatePPPOEname)){allUsersPhoneBook.Entries[updatePPPOEname].PhoneNumber = " ";// 不管当前PPPOE是否连接，服务器地址的更新总能成功，如果正在连接，则需要PPPOE重启后才能起作用 allUsersPhoneBook.Entries[updatePPPOEname].Update();}// 创建一个新PPPOEelse{string adds = string.Empty;ReadOnlyCollection<RasDevice> readOnlyCollection = RasDevice.GetDevices();// foreach (var col in readOnlyCollection)// {// adds += col.Name + ":" + col.DeviceType.ToString() + "|||";// }// _log.Info("Devices are : " + adds);// Find the device that will be used to dial the connection.RasDevice device = RasDevice.GetDevices().Where(o => o.DeviceType == RasDeviceType.PPPoE).First();RasEntry entry = RasEntry.CreateBroadbandEntry(updatePPPOEname, device); //建立宽带连接Entryentry.PhoneNumber = " ";allUsersPhoneBook.Entries.Add(entry);}}/// <summary>/// 断开 宽带连接/// </summary>public void Disconnect(){ReadOnlyCollection<RasConnection> conList = RasConnection.GetActiveConnections();foreach (RasConnection con in conList){con.HangUp();}}/// <summary>/// 宽带连接，成功返回true,失败返回 false/// </summary>/// <param name="PPPOEname">宽带连接名称</param>/// <param name="username">宽带账号</param>/// <param name="password">宽带密码</param>/// <returns></returns>public bool Connect(string PPPOEname, string username, string password,ref string msg ){try{CreateOrUpdatePPPOE(PPPOEname);using (RasDialer dialer = new RasDialer()){dialer.EntryName = PPPOEname;dialer.AllowUseStoredCredentials = true;dialer.Timeout = 1000;dialer.PhoneBookPath = RasPhoneBook.GetPhoneBookPath(RasPhoneBookType.AllUsers);dialer.Credentials = new NetworkCredential(username, password);dialer.Dial();return true;}}catch (RasException re){msg = re.ErrorCode + " " + re.Message;return false;}}}
