public static UserEndpoint ConnectLyncServer(string userSipUri, string lyncServer, bool usingSso, string username, string password)
        {
            // Create the Lync Server UserEndpoint and attempt to connect to Lync Server
            Console.WriteLine("{0} Connecting to Lync Server... [{1}]", username, lyncServer);

            // Use the appropriate SipTransportType depending on current Lync Server deployment
            ClientPlatformSettings platformSettings = new ClientPlatformSettings("PersistentChat.Test", SipTransportType.Tls);
            CollaborationPlatform  collabPlatform   = new CollaborationPlatform(platformSettings);

            collabPlatform.AllowedAuthenticationProtocol = SipAuthenticationProtocols.Ntlm;

            // Initialize the platform
            collabPlatform.EndStartup(collabPlatform.BeginStartup(null, null));

            // You can also pass in the server's port # here.
            UserEndpointSettings userEndpointSettings = new UserEndpointSettings(userSipUri, lyncServer);

            // When usingSso is true use the current users credentials, otherwise use username and password
            userEndpointSettings.Credential = usingSso ? SipCredentialCache.DefaultCredential : new NetworkCredential(username, password);

            UserEndpoint userEndpoint = new UserEndpoint(collabPlatform, userEndpointSettings);

            // Login to Lync Server.
            userEndpoint.EndEstablish(userEndpoint.BeginEstablish(null, null));

            if (PersistentChatServerUri == null)
            {
                // Extract default Persistent Chat pool uri from inband
                ProvisioningData provisioningData =
                    userEndpoint.EndGetProvisioningData(userEndpoint.BeginGetProvisioningData(null, null));
                PersistentChatServerUri = new Uri(provisioningData.PersistentChatConfiguration.DefaultPersistentChatUri);
                Console.WriteLine("\t-- {0}PersistentChatServerUri:{1}", username, PersistentChatServerUri);
            }

            Console.WriteLine("\t{0} Connecting>>>>Success", username);
            return(userEndpoint);
        }