Creating Call Center Applications with Unified Communications SDKs: Code Listing (Part 4 of 4)

Summary:   Learn how to use Unified Communications SDKs to implement speech synthesis, speech recognition, and call control technologies to create a simple call center application.

Applies to:   Microsoft Unified Communications Managed API (UCMA) 3.0 Core SDK or Microsoft Unified Communications Managed API 4.0 SDK | Microsoft Lync 2010 SDK | Microsoft Speech Platform SDK version (x64) 10.2

Published:   April 2012 | Provided by:   John Clarkson and Mark Parker, Microsoft | About the Author


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Watch video   See video

This is the last in a series of four articles about how to create a call center application.

The following example contains the code from the Program.cs file in the bot application.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

using System.Threading;
using Microsoft.Rtc.Collaboration;
using Microsoft.Rtc.Collaboration.AudioVideo;
using Microsoft.Rtc.Signaling;
using Microsoft.Rtc.Collaboration.Sample.Common;
using System.Configuration;
using Microsoft.Speech.Synthesis;
using Microsoft.Speech.Recognition;
using Microsoft.Speech.AudioFormat;

namespace SimpleCallCenter
    class Program

        #region Globals
        // The URI and connection server of the user to forward the call to.
        private String _transferUserURI;
        private UCMASampleHelper _helper;
        private UserEndpoint _userEndpoint;
        private AudioVideoCall _inboundAVCall, _outboundAVCall;
        private Microsoft.Rtc.Collaboration.Conversation _conversation;
        private ConversationContextChannel _channel;
        private CollaborationPlatform _collabPlatform;
        private AudioVideoFlow _audioVideoFlow;
        private string _name;
        private string _department;
        private SpeechSynthesisConnector _speechSynthesisConnector;
        private SpeechRecognitionConnector _speechRecognitionConnector;
        private SpeechSynthesizer _speechSynthesizer;
        private SpeechRecognitionEngine _speechRecognitionEngine;
        // Wait handles are used to synchronize the main thread and worker threads.
        private AutoResetEvent _waitForCallToBeTransferred = new AutoResetEvent(false);
        private AutoResetEvent _waitForCallToBeAccepted = new AutoResetEvent(false);
        private AutoResetEvent _waitForCallToBeEstablished = new AutoResetEvent(false);
        private AutoResetEvent _waitForShutdownEventCompleted = new AutoResetEvent(false);
        private AutoResetEvent _waitForRecoCompleted = new AutoResetEvent(false);

        static void Main(string[] args)
            Program program = new Program();

        private void Run()
            _helper = new UCMASampleHelper();
            _userEndpoint = _helper.CreateEstablishedUserEndpoint("Forwarding User" /*endpointFriendlyName*/);

            Console.WriteLine("Waiting for incoming call...");
            UCMASampleHelper.PauseBeforeContinuing("Press ENTER to shut down and exit.");

            // Shut down the sample.

        // Query caller for name and department.
        // This method is called from the AudioVideoCall_Received event handler.
        private void GetCallerInfo()

        public void PromptUserForDepartment()
            // Cache the Flow from the incoming call.
            _audioVideoFlow = _inboundAVCall.Flow;

            // Create a speech synthesis connector and attach the AudioVideoFlow instance to it.
            _speechSynthesisConnector = new SpeechSynthesisConnector();


            _speechSynthesizer = new SpeechSynthesizer();
            SpeechAudioFormatInfo audioformat = new SpeechAudioFormatInfo(16000, AudioBitsPerSample.Sixteen, Microsoft.Speech.AudioFormat.AudioChannel.Mono);
            _speechSynthesizer.SetOutputToAudioStream(_speechSynthesisConnector, audioformat);

            // Register for notification of the SpeakCompleted and SpeakStarted events on the speech synthesizer.
            _speechSynthesizer.SpeakStarted += new EventHandler<SpeakStartedEventArgs>(_speechSynthesizer_SpeakStarted);
            _speechSynthesizer.SpeakCompleted += new EventHandler<SpeakCompletedEventArgs>(_speechSynthesizer_SpeakCompleted);

            // Start the speech synthesis connector.
            _speechSynthesizer.Speak("Hello, can I connect you to billing or sales");

        public void RecognizeDepartmentName()
            // Create a speech recognition connector and attach it to a AudioVideoFlow.
            _speechRecognitionConnector = new SpeechRecognitionConnector();

            // Start recognizing.
            SpeechRecognitionStream stream = _speechRecognitionConnector.Start();

            // Create a speech recognition engine and start recognizing by attaching the connector to the recognition engine.
            _speechRecognitionEngine = new SpeechRecognitionEngine();
            _speechRecognitionEngine.SpeechRecognized += new EventHandler<SpeechRecognizedEventArgs>(speechRecognitionEngine_SpeechRecognized);
            _speechRecognitionEngine.SpeechRecognitionRejected += new EventHandler<SpeechRecognitionRejectedEventArgs>(_speechRecognitionEngine_SpeechRecognitionRejected);

            string[] departmentString = { "Sales", "Billing" };
            Choices departmentGrammar = new Choices(departmentString);
            _speechRecognitionEngine.LoadGrammar(new Grammar(new GrammarBuilder(departmentGrammar)));
            _speechRecognitionEngine.Grammars[0].Name = "department";

            string[] nameString = { "Terry Adams", "Toni Poe" };
            Choices nameGrammar = new Choices(nameString);
            _speechRecognitionEngine.LoadGrammar(new Grammar(new GrammarBuilder(nameGrammar)));
            _speechRecognitionEngine.Grammars[1].Name = "name";

            SpeechAudioFormatInfo speechAudioFormatInfo = new SpeechAudioFormatInfo(8000, AudioBitsPerSample.Sixteen, Microsoft.Speech.AudioFormat.AudioChannel.Mono);
            _speechRecognitionEngine.SetInputToAudioStream(stream, speechAudioFormatInfo);
            Console.WriteLine("\r\nGrammar loaded.");



        public void AskCallerName()
            _speechSynthesizer.Speak("And who shall I say is calling?");
        public void RecognizeName()
            Console.WriteLine("\r\nGrammar loaded names, say exit to shutdown.");

            try { _speechRecognitionEngine.RecognizeAsync(RecognizeMode.Multiple); }
            catch (Exception ex)

        // Send caller info to the agent.
        private void SendCallerInfo(AudioVideoCall call)
            Conversation conversation = call.Conversation;
            ParticipantEndpoint endpoint = call.RemoteEndpoint;
            Guid AppId = new Guid("client application GUID");
            _channel = new ConversationContextChannel(conversation, endpoint);
            ConversationContextChannelEstablishOptions options = new ConversationContextChannelEstablishOptions();
            options.ContextualData = SetCallerInfo();
            _channel.BeginEstablish(AppId, options, BeginContextEstablishCB, null);

        // Determine what caller info is sent to the agent.
        // In a "real" application, the information would come from a database.
        private string SetCallerInfo()
            string customerData = null;

            if (_name == "Toni Poe")
                customerData = "3;Toni Poe;3456.00";
            if (_name == "Terry Adams")
                customerData = "4;Terry Adams;6789.88";

            return customerData;

        public void SpeechPlatformShutDown()
            Console.WriteLine("department: " + _department);
            Console.WriteLine("name: " + _name);

            // Stop the connector.
            Console.WriteLine("Stopping the speech recognition connector");

            // Speech recognition connector must be detached from the flow, otherwise if the connector is rooted, it will keep the flow in memory.

            // Shut down the platform.


        #region EVENT HANDLERS
        void AudioVideoCall_Received(object sender, CallReceivedEventArgs<AudioVideoCall> e)
            //Type checking was done by the platform; no risk of this being any 
            // type other than the type expected.
            _inboundAVCall = e.Call;

            // Call: StateChanged: Only hooked up for logging, to show the call 
            // state transitions.
            _inboundAVCall.StateChanged += new

            Console.WriteLine("Call Received!");

            // Accept the call. Before transferring the call, it must be in the Established state.
            // Note that the docs are wrong in the state machine for the AVCall. BeginEstablish 
            // should be called on outgoing calls, not incoming calls.

            _inboundAVCall.BeginAccept(BeginAcceptCB, _inboundAVCall);

            // Wait for the call to be accepted, putting it into the Established state.
            Console.WriteLine("ServerFQDN call state is {0}\n", _inboundAVCall.State);

            // Query caller for department and name.

            // Which department should we transfer to?
            if(_department == "Sales")
                _transferUserURI = "SalesDepartmentURI";
            if (_department == "Billing")
                _transferUserURI = "BillingDepartmentURI";
            CallTransferOptions basicTransferOptions;
            IAsyncResult result;

            // Begin call transfer. 
            _conversation = new Conversation(_userEndpoint);
            _outboundAVCall = new AudioVideoCall(_conversation);
            _outboundAVCall.BeginEstablish(_transferUserURI, null, BeginEstablishCB, _outboundAVCall);

            basicTransferOptions = new CallTransferOptions(CallTransferType.Attended);
            result = _inboundAVCall.BeginTransfer(_outboundAVCall, basicTransferOptions, BeginTransferCB, _inboundAVCall);
            Console.WriteLine("Supervised transfer.");

            // Send contextual data.

        // Handler for the StateChanged event on the AudioVideoFlow object.
        private void audioVideoFlow_StateChanged(object sender, MediaFlowStateChangedEventArgs e)
            // When flow is active, media operations can begin.
            if (e.State == MediaFlowState.Terminated)
                // Detach SpeechRecognitionConnector, since AVFlow is terminated.
                AudioVideoFlow avFlow = (AudioVideoFlow)sender;
                if (avFlow.SpeechRecognitionConnector != null)

        // Handler for the StateChanged event on the inbound AudioVideoCall object.
        void inboundAVCall_StateChanged(object sender, CallStateChangedEventArgs e)
            Console.WriteLine("Inbound call has changed state.\n Previous call state: " + e.PreviousState +
                "\n Current call state: " + e.State);

        // Handler for the SpeechRecognized event on the speech recognition engine.
        // This method determines which grammar was used (department grammar or user name grammar)
        // and sets either _department or _name accordingly.
        void speechRecognitionEngine_SpeechRecognized(object sender, SpeechRecognizedEventArgs e)
            RecognitionResult result = e.Result;
            if (result != null)
                Console.WriteLine("Speech recognized: " + result.Text);

                if (result.Grammar.Name == "department")
                    _department = result.Text;

                else if (result.Grammar.Name == "name")
                    _name = result.Text;

                    Console.WriteLine("Speech not name or dept: " + result.Text);

        void _speechSynthesizer_SpeakCompleted(object sender, SpeakCompletedEventArgs e)
            Console.WriteLine("_speechSynthesizer_SpeakCompleted event handler");

        void _speechSynthesizer_SpeakStarted(object sender, SpeakStartedEventArgs e)
            Console.WriteLine("_speechSynthesizer_SpeakStarted event handler");

        void _speechRecognitionEngine_SpeechRecognitionRejected(object sender, SpeechRecognitionRejectedEventArgs e)
            Console.WriteLine("Speech reco rejected: " + e.Result.Text);


        #region CALLBACK METHODS
        // Callback for BeginAccept on the incoming call.
        void BeginAcceptCB(IAsyncResult ar)
            Console.WriteLine("Inbound call is accepted.\n");

        // Callback for BeginEstablish on the outgoing call.
        void BeginEstablishCB(IAsyncResult ar)
            Console.WriteLine("Outbound call is established.\n");

        // Callback for BeginTransfer on the incoming call.
        void BeginTransferCB(IAsyncResult ar)
                Console.WriteLine("Transfer completed.\n");
            catch (FailureResponseException fre)
                Console.WriteLine("Transfer failed: " + fre.ToString() + "\n");
            catch (OperationTimeoutException ote)
                Console.WriteLine("Transfer failed: " + ote.ToString() + "\n");
            catch (OperationFailureException ofe)
                Console.WriteLine("Transfer failed: " + ofe.ToString() + "\n");
            catch (FailureRequestException fre)
                Console.WriteLine("Transfer failed: " + fre.ToString() + "\n");


        // Callback for BeginContextEstablish on the context channel.
        void BeginContextEstablishCB(IAsyncResult res)
            if (_channel.State == ConversationContextChannelState.Establishing)
                Console.WriteLine("Context channel is in the Establishing state");


        #region PLATFORM CLEANUP
        private void ShutdownPlatform()
            // Shutdown the platform.     
            _collabPlatform = _audioVideoFlow.Call.Conversation.Endpoint.Platform;
            _collabPlatform.BeginShutdown(EndPlatformShutdown, _collabPlatform);

        private void EndPlatformShutdown(IAsyncResult ar)
            CollaborationPlatform collabPlatform = ar.AsyncState as CollaborationPlatform;

            // Shutdown actions will not throw.
            Console.WriteLine("The platform is now shutdown.");

            // Again, just to sync the completion of the code and the platform teardown.


The following examples show the code used to create the agent application.

Silverlight XAML Page

The following example shows the Microsoft Silverlight page .xaml file. This XAML text creates a button attached to a Click event handler in the code behind, and three text boxes with labels to display customer data.

<UserControl x:Class="SilverlightApplication4.MainPage"
    d:DesignHeight="300" d:DesignWidth="400">

    <Grid x:Name="LayoutRoot">

        <TextBox Height="23" HorizontalAlignment="Left" Margin="21,74,0,0" Name="textBoxCustomerID" VerticalAlignment="Top" Width="120" />
        <TextBox Height="23" HorizontalAlignment="Left" Margin="21,128,0,0" Name="textBoxCustomerName" VerticalAlignment="Top" Width="120" />
        <TextBox Height="23" HorizontalAlignment="Left" Margin="21,179,0,0" Name="textBoxCustomerBalance" VerticalAlignment="Top" Width="120" />
        <TextBlock Height="23" HorizontalAlignment="Left" Margin="173,78,0,0" Name="textBlock1" Text="ID" VerticalAlignment="Top" />
        <TextBlock Height="23" HorizontalAlignment="Left" Margin="173,132,0,0" Name="textBlock2" Text="Name" VerticalAlignment="Top" />
        <TextBlock Height="23" HorizontalAlignment="Left" Margin="173,179,0,0" Name="textBlock3" Text="Balance" VerticalAlignment="Top" />
        <Button Click="GetUserInfo_Click"  Content="GetUserInfo" Height="23" HorizontalAlignment="Left" Margin="21,33,0,0" Name="button1" VerticalAlignment="Top" Width="75" />

Silverlight Code-Behind Page

The following example shows the content of the Silverlight page code-behind file. This code obtains context data sent by the bot application, parses the data, and displays it in Silverlight controls on the XAML page.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;

using Microsoft.Lync.Model.Extensibility;
using Microsoft.Lync.Model.Conversation;

namespace SilverlightApplication4
    public partial class MainPage : UserControl
        public MainPage()

        private void GetUserInfo_Click(object sender, RoutedEventArgs e)
            //This GUID registers the application on this computer.
            //It is identical to the GUID for the bot application.
            string appId = "your application GUID";

            //Get the Conversation object from the Lync client.
            Conversation conversation = (Conversation)Microsoft.Lync.Model.LyncClient.GetHostingConversation();

            //The GetApplicationData method gets the data
            //sent from the bot. This is the information about the
            string text = conversation.GetApplicationData(appId);

            //Parse the string passed in as contextual data.
            char[] delimiter = { ';' };
            string[] custData = text.Split(delimiter);

            //Display array elements in text boxes.
            textBoxCustomerID.Text = custData[0];
            textBoxCustomerName.Text = custData[1];
            textBoxCustomerBalance.Text = custData[2];

Combine speech synthesis and speech recognition technologies with the call management features that are provided in the UCMA 3.0 Core SDK to create a call center application.

Mark Parker is a programming writer at Microsoft Corporation. His principal responsibility is the UCMA SDK documentation.

John Clarkson is also a programming writer on the Microsoft Lync feature team.