Manage calls

Install the SDK

Use the npm install command to install the Azure Communication Services Common and Calling SDK for JavaScript:

npm install @azure/communication-common --save
npm install @azure/communication-calling --save

Initialize required objects

A CallClient instance is required for most call operations. When you create a new CallClient instance, you can configure it with custom options like a Logger instance.

With the CallClient instance, you can create a CallAgent instance by calling the createCallAgent. This method asynchronously returns a CallAgent instance object.

The createCallAgent method uses CommunicationTokenCredential as an argument. It accepts a user access token.

You can use the getDeviceManager method on the CallClient instance to access deviceManager.

const { CallClient } = require('@azure/communication-calling');
const { AzureCommunicationTokenCredential} = require('@azure/communication-common');
const { AzureLogger, setLogLevel } = require("@azure/logger");

// Set the logger's log level
setLogLevel('verbose');

// Redirect log output to console, file, buffer, REST API, or whatever location you want
AzureLogger.log = (...args) => {
    console.log(...args); // Redirect log output to console
};

const userToken = '<USER_TOKEN>';
callClient = new CallClient(options);
const tokenCredential = new AzureCommunicationTokenCredential(userToken);
const callAgent = await callClient.createCallAgent(tokenCredential, {displayName: 'optional Azure Communication Services user name'});
const deviceManager = await callClient.getDeviceManager()

Manage SDK connectivity to Microsoft infrastructure

The Call Agent instance helps you manage calls (to join or start calls). In order to work your calling SDK needs to connect to Microsoft infrastructure to get notifications of incoming calls and coordinate other call details. Your Call Agent has two possible states:

Connected - A Call Agent connectionStatue value of Connected means the client SDK is connected and capable of receiving notifications from Microsoft infrastructure.

Disconnected - A Call Agent connectionStatue value of Disconnected states there's an issue that is preventing the SDK it from properly connecting. Call Agent should be re-created.

• invalidToken: If a token is expired or is invalid Call Agent instance disconnects with this error.
• connectionIssue: If there's an issue with the client connecting to Microsoft infrastructure, after many retries Call Agent exposes the connectionIssue error.

You can check if your local Call Agent is connected to Microsoft infrastructure by inspecting the current value of connectionState property. During an active call you can listen to the connectionStateChanged event to determine if Call Agent changes from Connected to Disconnected state.

const connectionState = callAgentInstance.connectionState;
console.log(connectionState); // it may return either of 'Connected' | 'Disconnected'

const connectionStateCallback = (args) => {
    console.log(args); // it will return an object with oldState and newState, each of having a value of either of 'Connected' | 'Disconnected'
    // it will also return reason, either of 'invalidToken' | 'connectionIssue'
}
callAgentInstance.on('connectionStateChanged', connectionStateCallback);

Place a call

To create and start a call, use one of the APIs on callAgent and provide a user that you created through the Communication Services identity SDK.

Call creation and start are synchronous. The call instance allows you to subscribe to call events.

Place a 1:n call to a user or PSTN

To call another Communication Services user, use the startCall method on callAgent and pass the recipient's CommunicationUserIdentifier that you created with the Communication Services administration library.

For a 1:1 call to a user, use the following code:

const userCallee = { communicationUserId: '<ACS_USER_ID>' }
const oneToOneCall = callAgent.startCall([userCallee]);

To place a call to a public switched telephone network (PSTN), use the startCall method on callAgent and pass the recipient's PhoneNumberIdentifier. Your Communication Services resource must be configured to allow PSTN calling.

When you call a PSTN number, specify your alternate caller ID. An alternate caller ID is a phone number (based on the E.164 standard) that identifies the caller in a PSTN call. It's the phone number the call recipient sees for an incoming call.

For a 1:1 call to a PSTN number, use the following code:

const pstnCallee = { phoneNumber: '<ACS_USER_ID>' }
const alternateCallerId = {phoneNumber: '<ALTERNATE_CALLER_ID>'};
const oneToOneCall = callAgent.startCall([pstnCallee], { alternateCallerId });

For a 1:n call to a user and a PSTN number, use the following code:

const userCallee = { communicationUserId: '<ACS_USER_ID>' }
const pstnCallee = { phoneNumber: '<PHONE_NUMBER>'};
const alternateCallerId = {phoneNumber: '<ALTERNATE_CALLER_ID>'};
const groupCall = callAgent.startCall([userCallee, pstnCallee], { alternateCallerId });

Join a room call

To join a room call, you can instantiate a context object with the roomId property as the room identifier. To join the call, use the join method and pass the context instance.

const context = { roomId: '<RoomId>' }
const call = callAgent.join(context);

A room offers application developers better control over who can join a call, when they meet and how they collaborate. For more information about rooms, see Rooms API for structured meetings and Join a room call.

Join a group call

To start a new group call or join an ongoing group call, use the join method and pass an object with a groupId property. The groupId value must be a GUID.

const context = { groupId: '<GUID>'};
const call = callAgent.join(context);

Receive an incoming call

The callAgent instance emits an incomingCall event when the logged-in identity receives an incoming call. To listen to this event, subscribe by using one of these options:

const incomingCallHandler = async (args: { incomingCall: IncomingCall }) => {
    const incomingCall = args.incomingCall;

    // Get incoming call ID
    var incomingCallId = incomingCall.id

    // Get information about this Call. This API is provided as a preview for developers
    // and may change based on feedback that we receive. Do not use this API in a production environment.
    // To use this api please use 'beta' release of Azure Communication Services Calling Web SDK
    var callInfo = incomingCall.info;

    // Get information about caller
    var callerInfo = incomingCall.callerInfo

    // Accept the call
    var call = await incomingCall.accept();

    // Reject the call
    incomingCall.reject();

    // Subscribe to callEnded event and get the call end reason
     incomingCall.on('callEnded', args => {
        console.log(args.callEndReason);
    });

    // callEndReason is also a property of IncomingCall
    var callEndReason = incomingCall.callEndReason;
};
callAgentInstance.on('incomingCall', incomingCallHandler);

The incomingCall event includes an incomingCall instance that you can accept or reject.

The Azure Communication Calling SDK raises a cameraStartFailed: true call diagnostic if the camera isn't available when starting, accepting, or joining a call with video enabled. In this case, the call starts with video off. The camera might not be available because it's being used by another process or is disabled in the operating system.

Hold and resume call

To hold or resume the call, use the hold and resume asynchronous APIs:

To hold the call:

await call.hold();

When hold operation resolves, the call state is set to LocalHold. In a 1:1 call, the other participant is also put on hold, and state of the call from the perspective of that participant is set to RemoteHold. Later, the other participant might put its call on hold, which would result in a state change to LocalHold.

In a group call or meeting - the hold is a local operation, it doesn't hold the call for other call participants.

To resume the call, all users who initiated hold must resume it.

To resume call from hold:

await call.resume();

When the resume operation resolves, the call state again sets to Connected.

Mute and unmute a call

To mute or unmute the local endpoint, use the mute and unmute asynchronous APIs:

//mute local device (microphone / sent audio)
await call.mute();

//unmute local device (microphone / sent audio)
await call.unmute();

Mute and unmute incoming audio

Mute incoming audio sets the call volume to 0. To mute or unmute the incoming audio, use the muteIncomingAudio and unmuteIncomingAudio asynchronous operations:

//mute local device (speaker)
await call.muteIncomingAudio();

//unmute local device (speaker)
await call.unmuteIncomingAudio();

When incoming audio is muted, the participant client SDK still receives the call audio (remote participant's audio). The call audio isn't heard in the speaker and the participant isn't able to listen until call.unmuteIncomingAudio() is called. However, we can apply a filter on call audio and play the filtered audio.

Manage remote participants

All remote participants are included in the RemoteParticipant object and available through the remoteParticipants collection on a call instance. The remoteParticipants object is accessible from a Call instance.

List the participants in a call

The remoteParticipants collection returns a list of remote participants in a call:

call.remoteParticipants; // [remoteParticipant, remoteParticipant....]

Add a participant to a call

To add a participant (either a user or a phone number) to a call, use the addParticipant operation. Provide one of the Identifier types. It synchronously returns the remoteParticipant instance. When a participant is successfully added to the call, it raises the remoteParticipantsUpdated event from Call.

const userIdentifier = { communicationUserId: '<ACS_USER_ID>' };
const pstnIdentifier = { phoneNumber: '<PHONE_NUMBER>' }
const remoteParticipant = call.addParticipant(userIdentifier);
const alternateCallerId = {  phoneNumber: '<ALTERNATE_CALLER_ID>' };
const remoteParticipant = call.addParticipant(pstnIdentifier, { alternateCallerId });

Remove a participant from a call

To remove a participant (either a user or a phone number) from a call, you can call removeParticipant. You have to pass one of the Identifier types. This method resolves asynchronously after removing the participant from the call. The participant is also removed from the remoteParticipants collection.

const userIdentifier = { communicationUserId: '<ACS_USER_ID>' };
const pstnIdentifier = { phoneNumber: '<PHONE_NUMBER>' }
await call.removeParticipant(userIdentifier);
await call.removeParticipant(pstnIdentifier);

Access remote participant properties

Remote participants have a set of associated properties and collections:

• CommunicationIdentifier: Get the identifier for a remote participant. Identity is one of the CommunicationIdentifier types:

  const identifier = remoteParticipant.identifier;
  

• It can be one of the following CommunicationIdentifier types:

  • { communicationUserId: '<ACS_USER_ID'> }: Object representing the Azure Communication Services user.
  • { phoneNumber: '<E.164>' }: Object representing the phone number in E.164 format.
  • { microsoftTeamsUserId: '<TEAMS_USER_ID>', isAnonymous?: boolean; cloud?: "public" | "dod" | "gcch" }: Object representing the Teams user.
  • { id: string }: object representing identifier that doesn't fit any of the other identifier types

• state: Get the state of a remote participant.

  const state = remoteParticipant.state;
  

• The state can be:

  • Idle: Initial state.
  • Connecting: Transition state while a participant is connecting to the call.
  • Ringing: Participant is ringing.
  • Connected: Participant is connected to the call.
  • Hold: Participant is on hold.
  • EarlyMedia: Announcement that plays before a participant connects to the call.
  • InLobby: Indicates that remote participant is in lobby.
  • Disconnected: Final state. The participant is disconnected from the call. If the remote participant loses their network connectivity, their state changes to Disconnected after two minutes.

• callEndReason: To learn why a participant left the call, check the callEndReason property:

  const callEndReason = remoteParticipant.callEndReason;
  const callEndReasonCode = callEndReason.code // (number) code associated with the reason
  const callEndReasonSubCode = callEndReason.subCode // (number) subCode associated with the reason
  

  Note

  This property is only set when adding a remote participant via the Call.addParticipant() API, and the remote participant declines for example.

  In the scenario, where UserB kicks UserC, from UserA's perspective, UserA doesn't see this flag get set for UserC. In other words, UserA doesn't see UserC's callEndReason property get set at all.

• isMuted status: To find out if a remote participant is muted, check the isMuted property. It returns Boolean.

  const isMuted = remoteParticipant.isMuted;
  

• isSpeaking status: To find out if a remote participant is speaking, check the isSpeaking property. It returns Boolean.

  const isSpeaking = remoteParticipant.isSpeaking;
  

• videoStreams: To inspect all video streams that a given participant is sending in this call, check the videoStreams collection. It contains RemoteVideoStream objects.

  const videoStreams = remoteParticipant.videoStreams; // [RemoteVideoStream, ...]
  

• displayName: To get display name for this remote participant, inspect displayName property it return string.

  const displayName = remoteParticipant.displayName;
  

• endpointDetails: Get the details of all the endpoints for this remote participant

  const endpointDetails: EndpointDetails[] = remoteParticipant.endpointDetails;
  

  Note

  A remote participant could be in the call from many possible endpoints, and each endpoint has its own unique participantId. participantId is different from the RemoteParticipant identifier's raw ID.

Mute other participants

To mute all other participants or mute a specific participant who is connected to a call, you can use the asynchronous APIs muteAllRemoteParticipants on the call and mute on the remote participant. The mutedByOthers event from Call is raised when the local participant is muted by others.

Muting a PSTN endpoint using the calling WebJS SDK is currently in GA and is available in build 1.34.1 1.34.1 and later versions.

//mute all participants except yourself
await call.muteAllRemoteParticipants();

//mute a specific participant
await call.remoteParticipants[0].mute();

Check call properties

Get the unique ID (string) for a call:

const callId: string = call.id;

Get the local participant ID:

const participantId: string = call.info.participantId;

Retrieve the thread ID if joining a Teams meeting:

const threadId: string | undefined = call.info.threadId;

Get information about the call:

const callInfo = call.info;

Learn about other participants in the call by inspecting the remoteParticipants collection on the call instance:

const remoteParticipants = call.remoteParticipants;

Identify the caller of an incoming call:

const callerIdentity = call.callerInfo.identifier;

identifier is one of the CommunicationIdentifier types.

Get the state of a call:

const callState = call.state;

This returns a string representing the current state of a call:

• None: Initial call state.
• Connecting: Initial transition state when a call is placed or accepted.
• Ringing: For an outgoing call, indicates that a call is ringing for remote participants. It's Incoming on their side.
• EarlyMedia: Indicates a state in which an announcement is played before the call is connected.
• Connected: Indicates that the call is connected.
• LocalHold: Indicates that a local participant the call put the call on hold. No media is flowing between the local endpoint and remote participants.
• RemoteHold: Indicates that a remote participant the call put the call on hold. No media is flowing between the local endpoint and remote participants.
• InLobby: Indicates that user is in lobby.
• Disconnecting: Transition state before the call goes to a Disconnected state.
• Disconnected: Final call state. If the network connection is lost, the state changes to Disconnected after two minutes.

Find out why a call ended by inspecting the callEndReason property:

const callEndReason = call.callEndReason;
const callEndReasonMessage = callEndReason.message // (string) user friendly message
const callEndReasonCode = callEndReason.code // (number) code associated with the reason
const callEndReasonSubCode = callEndReason.subCode // (number) subCode associated with the reason

Learn if the current call is incoming or outgoing by inspecting the direction property. It returns CallDirection.

const isIncoming = call.direction == 'Incoming';
const isOutgoing = call.direction == 'Outgoing';

Inspect the active video streams and active screen sharing streams by checking the localVideoStreams collection. The localVideoStreams operation returns LocalVideoStream objects of type Video, ScreenSharing, or RawMedia.

const localVideoStreams = call.localVideoStreams;

Check if the current microphone is muted. It returns Boolean.

const muted = call.isMuted;

Check if the current incoming audio (speaker) is muted. It returns Boolean.

const incomingAudioMuted = call.isIncomingAudioMuted;

Check if video is on. It returns Boolean.

const isLocalVideoStarted = call.isLocalVideoStarted;

Check is screen sharing is on. It returns Boolean.

const isScreenSharingOn = call.isScreenSharingOn;

Hang up

There are two ways to hang up the call.

• The initial caller can leave the call and the other participants remain in the call.
• When the initial caller leaves, the call terminates for all participants.

To leave the call, use:

call.hangUp();

End the call for all participants by providing HangUpOptions.

call.hangUp( forEveryone: true);

Install the SDK

Locate your project-level build.gradle file and add mavenCentral() to the list of repositories under buildscript and allprojects:

buildscript {
    repositories {
    ...
        mavenCentral()
    ...
    }
}

allprojects {
    repositories {
    ...
        mavenCentral()
    ...
    }
}

Then, in your module-level build.gradle file, add the following lines to the dependencies section:

dependencies {
    ...
    implementation 'com.azure.android:azure-communication-calling:1.0.0'
    ...
}

Initialize the required objects

To create a CallAgent instance, you have to call the createCallAgent method on a CallClient instance. This call asynchronously returns a CallAgent instance object.

The createCallAgent method takes CommunicationUserCredential as an argument, which encapsulates an access token.

To access DeviceManager, you must create a callAgent instance first. Then you can use the CallClient.getDeviceManager method to get DeviceManager.

String userToken = '<user token>';
CallClient callClient = new CallClient();
CommunicationTokenCredential tokenCredential = new CommunicationTokenCredential(userToken);
android.content.Context appContext = this.getApplicationContext(); // From within an activity, for instance
CallAgent callAgent = callClient.createCallAgent(appContext, tokenCredential).get();
DeviceManager deviceManager = callClient.getDeviceManager(appContext).get();

To set a display name for the caller, use this alternative method:

String userToken = '<user token>';
CallClient callClient = new CallClient();
CommunicationTokenCredential tokenCredential = new CommunicationTokenCredential(userToken);
android.content.Context appContext = this.getApplicationContext(); // From within an activity, for instance
CallAgentOptions callAgentOptions = new CallAgentOptions();
callAgentOptions.setDisplayName("Alice Bob");
DeviceManager deviceManager = callClient.getDeviceManager(appContext).get();
CallAgent callAgent = callClient.createCallAgent(appContext, tokenCredential, callAgentOptions).get();

Place a call

To create and start a call, you need to call the CallAgent.startCall() method and provide the Identifier of the recipient or recipients.

To join a group call, you need to call the CallAgent.join() method and provide the groupId. Group IDs must be in GUID or UUID format.

Call creation and start are synchronous. The call instance enables you to subscribe to all events on the call.

Place a 1:1 call to a user

To place a call to another Communication Services user, invoke the call method on callAgent and pass an object with communicationUserId key.

StartCallOptions startCallOptions = new StartCallOptions();
Context appContext = this.getApplicationContext();
CommunicationUserIdentifier acsUserId = new CommunicationUserIdentifier(<USER_ID>);
CommunicationUserIdentifier participants[] = new CommunicationUserIdentifier[]{ acsUserId };
call oneToOneCall = callAgent.startCall(appContext, participants, startCallOptions);

Place a 1:n call with users and PSTN

To place a 1:n call to a user and a public switched telephone network (PSTN) number, you need to specify the phone number of the recipient or recipients.

Your Communication Services resource must be configured to enable PSTN calling:

CommunicationUserIdentifier acsUser1 = new CommunicationUserIdentifier(<USER_ID>);
PhoneNumberIdentifier acsUser2 = new PhoneNumberIdentifier("<PHONE_NUMBER>");
CommunicationIdentifier participants[] = new CommunicationIdentifier[]{ acsUser1, acsUser2 };
StartCallOptions startCallOptions = new StartCallOptions();
Context appContext = this.getApplicationContext();
Call groupCall = callAgent.startCall(participants, startCallOptions);

Accept a call

To accept a call, call the accept method on a call object.

Context appContext = this.getApplicationContext();
IncomingCall incomingCall = retrieveIncomingCall();
Call call = incomingCall.accept(context).get();

To accept a call with video camera on:

Context appContext = this.getApplicationContext();
IncomingCall incomingCall = retrieveIncomingCall();
AcceptCallOptions acceptCallOptions = new AcceptCallOptions();
VideoDeviceInfo desiredCamera = callClient.getDeviceManager().get().getCameraList().get(0);
acceptCallOptions.setVideoOptions(new VideoOptions(new LocalVideoStream(desiredCamera, appContext)));
Call call = incomingCall.accept(context, acceptCallOptions).get();

Obtain the incoming call by subscribing to the onIncomingCall event on the callAgent object:

// Assuming "callAgent" is an instance property obtained by calling the 'createCallAgent' method on CallClient instance 
public Call retrieveIncomingCall() {
    IncomingCall incomingCall;
    callAgent.addOnIncomingCallListener(new IncomingCallListener() {
        void onIncomingCall(IncomingCall inboundCall) {
            // Look for incoming call
            incomingCall = inboundCall;
        }
    });
    return incomingCall;
}

Join a room call

Use the CallAgent and RoomCallLocator to join a room call by specifying a roomId. The CallAgent.join method returns a Call object:

val roomCallLocator = RoomCallLocator(roomId)
call = callAgent.join(applicationContext, roomCallLocator, joinCallOptions)

A room offers application developers better control over who can join a call, when they meet and how they collaborate. For more information about rooms, see Rooms API for structured meetings and Join a room call.

Join a group call

To start a new group call or join an ongoing group call, you need to call the join method and pass an object with a groupId property. The value has to be a GUID.

Context appContext = this.getApplicationContext();
GroupCallLocator groupCallLocator = new GroupCallLocator("<GUID>");
JoinCallOptions joinCallOptions = new JoinCallOptions();

call = callAgent.join(context, groupCallLocator, joinCallOptions);

Call properties

Get the unique ID for this Call:

String callId = call.getId();

To learn about other participants in the call inspect remoteParticipant collection on the call instance:

List<RemoteParticipant> remoteParticipants = call.getRemoteParticipants();

The identity of caller if the call is incoming:

CommunicationIdentifier callerId = call.getCallerInfo().getIdentifier();

Get the state of the Call:

CallState callState = call.getState();

It returns a string representing the current state of a call:

• NONE - initial call state
• EARLY_MEDIA - indicates a state in which an announcement is played before call is connected
• CONNECTING - initial transition state once call is placed or accepted
• RINGING - for an outgoing call - indicates call is ringing for remote participants
• CONNECTED - call connected
• LOCAL_HOLD - call placed on hold by local participant with no media flowing between local endpoint and remote participants
• REMOTE_HOLD - call placed on hold by a remote participant with no media flowing between local endpoint and remote participants
• DISCONNECTING - transition state before call goes to Disconnected state
• DISCONNECTED - final call state
• IN_LOBBY - in lobby for a Teams meeting interoperability

To learn why a call ended, inspect callEndReason property. It contains code/subcode:

CallEndReason callEndReason = call.getCallEndReason();
int code = callEndReason.getCode();
int subCode = callEndReason.getSubCode();

To see if the current call is an incoming or an outgoing call, inspect callDirection property:

CallDirection callDirection = call.getCallDirection(); 
// callDirection == CallDirection.INCOMING for incoming call
// callDirection == CallDirection.OUTGOING for outgoing call

To see if the current microphone is muted, inspect the muted property:

boolean muted = call.isMuted();

To inspect active video streams, check the localVideoStreams collection:

List<LocalVideoStream> localVideoStreams = call.getLocalVideoStreams();

Mute and unmute

To mute or unmute the local endpoint, you can use the mute and unmute asynchronous APIs:

Context appContext = this.getApplicationContext();
call.mute(appContext).get();
call.unmute(appContext).get();

Change the volume of the call

While participants are in a call, the hardware volume keys on the phone should enable the user to change the call volume.

Use the method setVolumeControlStream with the stream type AudioManager.STREAM_VOICE_CALL on the Activity where the call is happening.

This method enables the hardware volume keys to change the volume of the call, denoted by a phone icon or something similar on the volume slider. It also prevents changes to volume by other sound profiles, like alarms, media, or system wide volume. For more information, see Handling changes in audio output | Android Developers.

@Override
protected void onCreate(Bundle savedInstanceState) {
    ...
    setVolumeControlStream(AudioManager.STREAM_VOICE_CALL);
}

Remote participants management

All remote participants have the RemoteParticipant type and are available through the remoteParticipants collection on a call instance.

List participants in a call

The remoteParticipants collection returns a list of remote participants in given call:

List<RemoteParticipant> remoteParticipants = call.getRemoteParticipants(); // [remoteParticipant, remoteParticipant....]

Add a participant to a call

To add a participant to a call (either a user or a phone number), you can call the addParticipant operation.

This operation synchronously returns the remote participant instance.

const acsUser = new CommunicationUserIdentifier("<acs user id>");
const acsPhone = new PhoneNumberIdentifier("<phone number>");
RemoteParticipant remoteParticipant1 = call.addParticipant(acsUser);
AddPhoneNumberOptions addPhoneNumberOptions = new AddPhoneNumberOptions(new PhoneNumberIdentifier("<alternate phone number>"));
RemoteParticipant remoteParticipant2 = call.addParticipant(acsPhone, addPhoneNumberOptions);

Remove participant from a call

To remove a participant from a call (either a user or a phone number), you can call the removeParticipant operation.

This operation resolves asynchronously once the participant is removed from the call.

The participant is also removed from remoteParticipants collection.

RemoteParticipant acsUserRemoteParticipant = call.getParticipants().get(0);
RemoteParticipant acsPhoneRemoteParticipant = call.getParticipants().get(1);
call.removeParticipant(acsUserRemoteParticipant).get();
call.removeParticipant(acsPhoneRemoteParticipant).get();

Remote participant properties

Any given remote participant has a set of associated properties and collections:

• Get the identifier for this remote participant.

Identity is one of the Identifier types:

CommunicationIdentifier participantIdentifier = remoteParticipant.getIdentifier();

• Get the state of this remote participant.

  ParticipantState state = remoteParticipant.getState();
  

State can be one of:

• IDLE - initial state

• EARLY_MEDIA - announcement is played before participant is connected to the call

• RINGING - participant call is ringing

• CONNECTING - transition state while participant is connecting to the call

• CONNECTED - participant is connected to the call

• HOLD - participant is on hold

• IN_LOBBY - participant is waiting in the lobby to be admitted. Currently only used in Teams interop scenario

• DISCONNECTED - final state - participant is disconnected from the call

• To learn why a participant left the call, inspect callEndReason property:

  CallEndReason callEndReason = remoteParticipant.getCallEndReason();
  

• To check whether this remote participant is muted or not, inspect the isMuted property:

  boolean isParticipantMuted = remoteParticipant.isMuted();
  

• To check whether this remote participant is speaking or not, inspect the isSpeaking property:

  boolean isParticipantSpeaking = remoteParticipant.isSpeaking();
  

• To inspect all video streams that a given participant is sending in this call, check the videoStreams collection:

  List<RemoteVideoStream> videoStreams = remoteParticipant.getVideoStreams(); // [RemoteVideoStream, RemoteVideoStream, ...]
  

Mute other participants

When a PSTN participant is muted, they receive an announcement that they're muted and that they can press a key combination (such as *6) to unmute themselves. When they press *6, they are unmuted.

To mute all other participants in a call, use the muteAllRemoteParticipants API operation.

call.muteAllRemoteParticipants();

To mute a specific remote participant, use the mute API operation on a given remote participant.

remoteParticipant.mute();

To notify the local participant that they're muted by others, subscribe to the onMutedByOthers event.

Using Foreground Services

If you want to run a user-visible task even when your application is in background, you can use Foreground Services.

Use Foreground Services, for example, to provide users with a visible notification when your application has an active call. This way, even if the user goes to the homescreen or removes the application from the recents screen, the call continues to be active.

If you don't use a Foreground Service while in a call, navigating to the homescreen can keep the call active, but removing the application from the recent's screen can stop the call if the Android OS kills your application's process.

You should start the Foreground Service when a user starts or joins a call, for example:

call = callAgent.startCall(context, participants, options);
startService(yourForegroundServiceIntent);

You should also stop the Foreground Service when you hang up the call or the call's status is Disconnected, for example:

call.hangUp(new HangUpOptions()).get();
stopService(yourForegroundServiceIntent);

Foreground Service details

Keep in mind that scenarios like stopping an already running Foreground Service when the app is removed from the recent's list removes the user-visible notification. In this case the Android OS can keep your application process alive for some extra period of time, meaning that the call can remain active during this period.

If your application is stopping the Foreground Service on the service onTaskRemoved method, for example, your application can start or stop audio and video according to your Activity Lifecycle. Such as stopping audio and video when your activity is destroyed with the onDestroy method override.

Set up your system

Follow these steps to set up your system.

Create the Xcode project

In Xcode, create a new iOS project and select the Single View App template. This article uses the SwiftUI framework, so you should set Language to Swift and set Interface to SwiftUI.

You're not going to create tests in this article. Feel free to clear the Include Tests checkbox.

Install the package and dependencies by using CocoaPods

1. Create a Podfile for your application, like this example:

   platform :ios, '13.0'
   use_frameworks!
   target 'AzureCommunicationCallingSample' do
       pod 'AzureCommunicationCalling', '~> 1.0.0'
   end
   

2. Run pod install.

3. Open .xcworkspace by using Xcode.

Request access to the microphone

To access the device's microphone, you need to update your app's information property list by using NSMicrophoneUsageDescription. Set the associated value to a string that's included in the dialog that the system uses to request access from the user.

Right-click the Info.plist entry of the project tree, and then select Open As > Source Code. Add the following lines in the top-level <dict> section, and then save the file.

<key>NSMicrophoneUsageDescription</key>
<string>Need microphone access for VOIP calling.</string>

Set up the app framework

Open your project's ContentView.swift file. Add an import declaration to the top of the file to import the AzureCommunicationCalling library. In addition, import AVFoundation. You need it for audio permission requests in the code.

import AzureCommunicationCalling
import AVFoundation

Initialize CallAgent

To create a CallAgent instance from CallClient, you have to use a callClient.createCallAgent method that asynchronously returns a CallAgent object after it's initialized.

To create a call client, pass a CommunicationTokenCredential object:

import AzureCommunication

let tokenString = "token_string"
var userCredential: CommunicationTokenCredential?
do {
    let options = CommunicationTokenRefreshOptions(initialToken: token, refreshProactively: true, tokenRefresher: self.fetchTokenSync)
    userCredential = try CommunicationTokenCredential(withOptions: options)
} catch {
    updates("Couldn't created Credential object", false)
    initializationDispatchGroup!.leave()
    return
}

// tokenProvider needs to be implemented by Contoso, which fetches a new token
public func fetchTokenSync(then onCompletion: TokenRefreshOnCompletion) {
    let newToken = self.tokenProvider!.fetchNewToken()
    onCompletion(newToken, nil)
}

Pass the CommunicationTokenCredential object that you created to CallClient, and set the display name:

self.callClient = CallClient()
let callAgentOptions = CallAgentOptions()
options.displayName = " iOS Azure Communication Services User"

self.callClient!.createCallAgent(userCredential: userCredential!,
    options: callAgentOptions) { (callAgent, error) in
        if error == nil {
            print("Create agent succeeded")
            self.callAgent = callAgent
        } else {
            print("Create agent failed")
        }
})

Place an outgoing call

To create and start a call, you need to call one of the APIs on CallAgent and provide the Communication Services identity of a user that you've provisioned by using the Communication Services Management SDK.

Call creation and start are synchronous. You receive a call instance that enables you to subscribe to all events on the call.

Place a 1:1 call to a user or a 1:n call with users and PSTN

let callees = [CommunicationUser(identifier: 'UserId')]
self.callAgent?.startCall(participants: callees, options: StartCallOptions()) { (call, error) in
     if error == nil {
         print("Successfully started outgoing call")
         self.call = call
     } else {
         print("Failed to start outgoing call")
     }
}

Place a 1:n call with users and PSTN

To place a 1:n call to a user and a public switched telephone network (PSTN), you need to specify a phone number acquired with Communication Services.

let pstnCallee = PhoneNumberIdentifier(phoneNumber: '+1999999999')
let callee = CommunicationUserIdentifier('UserId')
self.callAgent?.startCall(participants: [pstnCallee, callee], options: StartCallOptions()) { (groupCall, error) in
     if error == nil {
         print("Successfully started outgoing call to multiple participants")
         self.call = groupCall
     } else {
         print("Failed to start outgoing call to multiple participants")
     }
}

Join a room call

To join a room call, specify the roomId property as the room identifier. To join the call, use the join method and pass the roomCallLocator.

func joinRoomCall() {
    if self.callAgent == nil {
        print("CallAgent not initialized")
        return
    }
    
    if (self.roomId.isEmpty) {
        print("Room ID not set")
        return
    }
    
    // Join a call with a Room ID
    let options = JoinCallOptions()
    let audioOptions = AudioOptions()
    audioOptions.muted = self.muted
    
    options.audioOptions = audioOptions
    
    let roomCallLocator = RoomCallLocator(roomId: roomId)
    self.callAgent!.join(with: roomCallLocator, joinCallOptions: options) { (call, error) in
        self.setCallAndObserver(call: call, error: error)
    }
}

A room offers application developers better control over who can join a call, when they meet and how they collaborate. For more information about rooms, see Rooms API for structured meetings and Join a room call.

Join a group call

To join a call, you need to call one of the APIs on CallAgent.

let groupCallLocator = GroupCallLocator(groupId: UUID(uuidString: "uuid_string")!)
self.callAgent?.join(with: groupCallLocator, joinCallOptions: JoinCallOptions()) { (call, error) in
    if error == nil {
        print("Successfully joined group call")
        self.call = call
    } else {
        print("Failed to join group call")
    }
}

Subscribe to an incoming call

Subscribe to an incoming call event.

final class IncomingCallHandler: NSObject, CallAgentDelegate, IncomingCallDelegate
{
    // Event raised when there is an incoming call
    public func callAgent(_ callAgent: CallAgent, didReceiveIncomingCall incomingcall: IncomingCall) {
        self.incomingCall = incomingcall
        // Subscribe to get OnCallEnded event
        self.incomingCall?.delegate = self
    }

    // Event raised when incoming call was not answered
    public func incomingCall(_ incomingCall: IncomingCall, didEnd args: PropertyChangedEventArgs) {
        print("Incoming call was not answered")
        self.incomingCall = nil
    }
}

Accept an incoming call

To accept a call, call the accept method on a IncomingCall object.

self.incomingCall!.accept(options: AcceptCallOptions()) { (call, error) in
   if (error == nil) {
       print("Successfully accepted incoming call")
       self.call = call
   } else {
       print("Failed to accept incoming call")
   }
}

let firstCamera: VideoDeviceInfo? = self.deviceManager!.cameras.first
localVideoStreams = [LocalVideoStream]()
localVideoStreams!.append(LocalVideoStream(camera: firstCamera!))
let acceptCallOptions = AcceptCallOptions()
acceptCallOptions.videoOptions = VideoOptions(localVideoStreams: localVideoStreams!)
if let incomingCall = self.incomingCall {
    incomingCall.accept(options: acceptCallOptions) { (call, error) in
        if error == nil {
            print("Incoming call accepted")
        } else {
            print("Failed to accept incoming call")
        }
    }
} else {
  print("No incoming call found to accept")
}

Perform mid-call operations

You can perform operations during a call to manage settings related to video and audio.

Mute and unmute

To mute or unmute the local endpoint, you can use the mute and unmute asynchronous APIs.

call!.mute { (error) in
    if error == nil {
        print("Successfully muted")
    } else {
        print("Failed to mute")
    }
}

Use the following code to unmute the local endpoint asynchronously.

call!.unmute { (error) in
    if error == nil {
        print("Successfully un-muted")
    } else {
        print("Failed to unmute")
    }
}

Manage remote participants

The RemoteParticipant type represents all remote participants. They're available through the remoteParticipants collection on a call instance.

List participants in a call

call.remoteParticipants

Add a participant to a call

To add a participant to a call as either a user or a phone number, call the addParticipant operation. This operation synchronously returns a remote participant instance.

let remoteParticipantAdded: RemoteParticipant = call.add(participant: CommunicationUserIdentifier(identifier: "userId"))

Remove a participant from a call

To remove a participant from a call as either a user or a phone number, call the removeParticipant operation. This operation resolves asynchronously.

call!.remove(participant: remoteParticipantAdded) { (error) in
    if (error == nil) {
        print("Successfully removed participant")
    } else {
        print("Failed to remove participant")
    }
}

Get remote participant properties

// [RemoteParticipantDelegate] delegate - an object you provide to receive events from this RemoteParticipant instance
var remoteParticipantDelegate = remoteParticipant.delegate

// [CommunicationIdentifier] identity - same as the one used to provision a token for another user
var identity = remoteParticipant.identifier

// ParticipantStateIdle = 0, ParticipantStateEarlyMedia = 1, ParticipantStateConnecting = 2, ParticipantStateConnected = 3, ParticipantStateOnHold = 4, ParticipantStateInLobby = 5, ParticipantStateDisconnected = 6
var state = remoteParticipant.state

// [Error] callEndReason - reason why participant left the call, contains code/subcode/message
var callEndReason = remoteParticipant.callEndReason

// [Bool] isMuted - indicating if participant is muted
var isMuted = remoteParticipant.isMuted

// [Bool] isSpeaking - indicating if participant is currently speaking
var isSpeaking = remoteParticipant.isSpeaking

// RemoteVideoStream[] - collection of video streams this participants has
var videoStreams = remoteParticipant.videoStreams // [RemoteVideoStream, RemoteVideoStream, ...]

Mute other participants

When a PSTN participant is muted, they receive an announcement that they're muted and that they can press a key combination (such as *6) to unmute themselves. When they press *6, they're unmuted.

To mute all other participants in a call, use the muteAllRemoteParticipants operation on the call.

call!.muteAllRemoteParticipants { (error) in
    if error == nil {
        print("Successfully muted all remote participants.")
    } else {
        print("Failed to mute remote participants.")
    }
}

To mute a specific remote participant, use the mute operation on a given remote participant.

remoteParticipant.mute { (error) in
    if error == nil {
        print("Successfully muted participant.")
    } else {
        print("Failed to mute participant.")
    }
}

To notify the local participant that they're muted by others, subscribe to the onMutedByOthers event.

Set up your system

Follow these steps to set up your system.

Create the Visual Studio project

For a Universal Windows Platform app, in Visual Studio 2022, create a new Blank App (Universal Windows) project. After you enter the project name, feel free to choose any Windows SDK later than 10.0.17763.0.

For a WinUI 3 app, create a new project with the Blank App, Packaged (WinUI 3 in Desktop) template to set up a single-page WinUI 3 app. Windows App SDK version 1.3 or later is required.

Install the package and dependencies by using NuGet Package Manager

The Calling SDK APIs and libraries are publicly available via a NuGet package.

To find, download, and install the Calling SDK NuGet package:

1. Open NuGet Package Manager by selecting Tools > NuGet Package Manager > Manage NuGet Packages for Solution.
2. Select Browse, and then enter Azure.Communication.Calling.WindowsClient in the search box.
3. Make sure that the Include prerelease checkbox is selected.
4. Select the Azure.Communication.Calling.WindowsClient package, and then select Azure.Communication.Calling.WindowsClient 1.4.0-beta.1 or a newer version.
5. Select the checkbox that corresponds to the Azure Communication Services project on the right pane.
6. Select Install.

Implement the sample app in Visual Studio

This section describes how to develop the app to manage calls working in Visual Studio.

Request access to the microphone

The app requires access to the microphone. In Universal Windows Platform (UWP) apps, the microphone capability must be declared in the app manifest file.

To access the microphone:

1. In the Solution Explorer panel, double click on the file with .appxmanifest extension.
2. Click on the Capabilities tab.
3. Select the Microphone check box from the capabilities list.

Create UI buttons to place and hang up the call

This sample app contains two buttons. One for placing the call and another to hang up a placed call.

Add two buttons to the app.

1. In the Solution Explorer panel, double click on the file named MainPage.xaml for UWP, or MainWindows.xaml for WinUI 3.
2. In the central panel, look for the XAML code under the UI preview.
3. Modify the XAML code by the following excerpt:

<TextBox x:Name="CalleeTextBox" PlaceholderText="Who would you like to call?" />
<StackPanel>
    <Button x:Name="CallButton" Content="Start/Join call" Click="CallButton_Click" />
    <Button x:Name="HangupButton" Content="Hang up" Click="HangupButton_Click" />
</StackPanel>

Set up the app with Calling SDK APIs

The Calling SDK APIs are in two different namespaces.

The following steps inform the C# compiler about these namespaces, enabling Visual Studio's Intellisense to help with code development.

1. In the Solution Explorer panel, click on the arrow on the left side of the file named MainPage.xaml for UWP, or MainWindows.xaml for WinUI 3.
2. Double click on file named MainPage.xaml.cs or MainWindows.xaml.cs.
3. Add the following commands at the bottom of the current using statements.

using Azure.Communication.Calling.WindowsClient;

Keep MainPage.xaml.cs or MainWindows.xaml.cs open. The next steps add more code.

Enable app interactions

The UI buttons previously added need to operate on top of a placed CommunicationCall. It means that a CommunicationCall data member should be added to the MainPage or MainWindow class. Additionally, to allow the asynchronous operation creating CallAgent to succeed, a CallAgent data member should also be added to the same class.

Add the following data members to the MainPage pr MainWindow class:

CallAgent callAgent;
CommunicationCall call;

Create button handlers

Previously, two UI buttons were added to the XAML code. The following code adds the handlers to be executed when a user selects the button. The following code should be added after the data members from the previous section.

private async void CallButton_Click(object sender, RoutedEventArgs e)
{
    // Start call
}

private async void HangupButton_Click(object sender, RoutedEventArgs e)
{
    // End the current call
}

Object model

The following classes and interfaces handle some of the major features of the Azure Communication Services Calling client library for UWP.

Name	Description
CallClient	The CallClient is the main entry point to the Calling client library.
CallAgent	The CallAgent is used to start and join calls.
CommunicationCall	The CommunicationCall is used to manage placed or joined calls.
CommunicationTokenCredential	The CommunicationTokenCredential is used as the token credential to instantiate the CallAgent.
CallAgentOptions	The CallAgentOptions contains information to identify the caller.
HangupOptions	The HangupOptions informs if a call should be terminated to all its participants.

Initialize the CallAgent

To create a CallAgent instance from CallClient, you must use CallClient.CreateCallAgentAsync method that asynchronously returns a CallAgent object once it's initialized.

To create CallAgent, you must pass a CallTokenCredential object and a CallAgentOptions object. Keep in mind that CallTokenCredential throws if a malformed token is passed.

To call during app initialization, add the following code inside and helper function.

var callClient = new CallClient();
this.deviceManager = await callClient.GetDeviceManagerAsync();

var tokenCredential = new CallTokenCredential("<AUTHENTICATION_TOKEN>");
var callAgentOptions = new CallAgentOptions()
{
    DisplayName = "<DISPLAY_NAME>"
};

this.callAgent = await callClient.CreateCallAgentAsync(tokenCredential, callAgentOptions);

Change the <AUTHENTICATION_TOKEN> with a valid credential token for your resource. If you need to source a credential token, see user access token.

Create CallAgent and place a call

The objects you need to create a CallAgent are now ready. It's time to asynchronously create CallAgent and place a call.

Add the following code after handling the exception from the previous step.

var startCallOptions = new StartCallOptions();
var callees = new [] { new UserCallIdentifier(CalleeTextBox.Text.Trim()) };

this.call = await this.callAgent.StartCallAsync(callees, startCallOptions);
this.call.OnStateChanged += Call_OnStateChangedAsync;

Use 8:echo123 to talk to the Azure Communication Services echo bot.

Mute and unmute

To mute or unmute the outgoing audio, use the MuteOutgoingAudioAsync and UnmuteOutgoingAudioAsync asynchronous operations:

// mute outgoing audio
await this.call.MuteOutgoingAudioAsync();

// unmute outgoing audio
await this.call.UnmuteOutgoingAudioAsync();

Mute other participants

When a PSTN participant is muted, they must receive an announcement that they have been muted and that they can press a key combination (such as *6) to unmute themselves. When they press *6, they must be unmuted.

To mute all other participants or mute a specific participant, use the asynchronous operations MuteAllRemoteParticipantsAsync on the call and MuteAsync on the remote participant:

// mute all participants except yourself
await this.call.MuteAllRemoteParticipantsAsync();

// mute specific participant in the call
await this.call.RemoteParticipants.FirstOrDefault().MuteAsync();

To notify the local participant that they're muted by others, subscribe to the MutedByOthers event.

End a call

Once a call is placed, use the HangupAsync method of the CommunicationCall object to hang up the call.

Use an instance of HangupOptions to inform all participants if the call must be terminated.

Add the following code inside HangupButton_Click:

this.call.OnStateChanged -= Call_OnStateChangedAsync;
await this.call.HangUpAsync(new HangUpOptions() { ForEveryone = false });

Run the code

1. Make sure Visual Studio builds the app for x64, x86 or ARM64.
2. Press F5 to start running the app.
3. Once the app is running, click the Call button to place a call to the defined recipient.

The first time the app runs, the system prompts the user to grant access to the microphone.