Android provides an API that supports the Session Initiation Protocol (SIP). This lets you add SIP-based internet telephony features to your applications. Android includes a full SIP protocol stack and integrated call management services that let applications easily set up outgoing and incoming voice calls, without having to manage sessions, transport-level communication, or audio record or playback directly.
Here are examples of the types of applications that might use the SIP API:
Here are the requirements for developing a SIP application:
Here is a summary of the classes and one interface
(SipRegistrationListener) that are included in the Android SIP
API:
| Class/Interface | Description |
|---|---|
SipAudioCall |
Handles an Internet audio call over SIP. |
SipAudioCall.Listener |
Listener for events relating to a SIP call, such as when a call is being received ("on ringing") or a call is outgoing ("on calling"). |
SipErrorCode |
Defines error codes returned during SIP actions. |
SipManager |
Provides APIs for SIP tasks, such as initiating SIP connections, and provides access to related SIP services. |
SipProfile |
Defines a SIP profile, including a SIP account, domain and server information. |
SipProfile.Builder |
Helper class for creating a SipProfile. |
SipSession |
Represents a SIP session that is associated with a SIP dialog or a standalone transaction not within a dialog. |
SipSession.Listener |
Listener for events relating to a SIP session, such as when a session is being registered ("on registering") or a call is outgoing ("on calling"). |
SipSession.State |
Defines SIP session states, such as "registering", "outgoing call", and "in call". |
SipRegistrationListener |
An interface that is a listener for SIP registration events. |
If you are developing an application that uses the SIP API, remember that the feature is supported only on Android 2.3 (API level 9) and higher versions of the platform. Also, among devices running Android 2.3 (API level 9) or higher, not all devices will offer SIP support.
To use SIP, add the following permissions to your application's manifest:
android.permission.USE_SIPandroid.permission.INTERNETTo ensure that your application can only be installed on devices that are capable of supporting SIP, add the following to your application's manifest:
<uses-sdk android:minSdkVersion="9" />. This
indicates that your application requires Android 2.3 or higher. For more
information, see API
Levels and the documentation for the <uses-sdk> element.To control how your application is filtered from devices that do not support SIP (for example, in Android Market), add the following to your application's manifest:
<uses-feature android:name="android.hardware.sip.voip"
/>. This states that your application uses the SIP API. The
declaration should include an android:required attribute that
indicates whether you want the application to be filtered from devices that do
not offer SIP support. Other <uses-feature> declarations
may also be needed, depending on your implementation. For more information,
see the documentation for the <uses-
feature> element.If your application is designed to receive calls, you must also define a receiver (BroadcastReceiver subclass) in the application's manifest:
<receiver android:name=".IncomingCallReceiver" android:label="Call Receiver"/>Here are excerpts from the SipDemo manifest:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.android.sip">
...
<receiver android:name=".IncomingCallReceiver" android:label="Call Receiver"/>
...
<uses-sdk android:minSdkVersion="9" />
<uses-permission android:name="android.permission.USE_SIP" />
<uses-permission android:name="android.permission.INTERNET" />
...
<uses-feature android:name="android.hardware.sip.voip" android:required="true" />
<uses-feature android:name="android.hardware.wifi" android:required="true" />
<uses-feature android:name="android.hardware.microphone" android:required="true" />
</manifest>
To use the SIP API, your application must create a SipManager object. The SipManager takes
care of the following in your application:
You instantiate a new SipManager as follows:
public SipManager mSipManager = null;
...
if(mSipManager == null) {
mSipManager = SipManager.newInstance(this);
}
A typical Android SIP application involves one or more users, each of whom
has a SIP account. In an Android SIP application, each SIP account is
represented by a SipProfile object.
A SipProfile defines a SIP profile, including a SIP
account, and domain and server information. The profile associated with the SIP
account on the device running the application is called the local
profile. The profile that the session is connected to is called the
peer profile. When your SIP application logs into the SIP server with
the local SipProfile, this effectively registers the
device as the location to send SIP calls to for your SIP address.
This section shows how to create a SipProfile,
register it with a SIP server, and track registration events.
You create a SipProfile object as follows:
public SipProfile mSipProfile = null; ... SipProfile.Builder builder = new SipProfile.Builder(username, domain); builder.setPassword(password); mSipProfile = builder.build();
The following code excerpt opens the local profile for making calls and/or
receiving generic SIP calls. The caller can make subsequent calls through
mSipManager.makeAudioCall. This excerpt also sets the action
android.SipDemo.INCOMING_CALL, which will be used by an intent
filter when the device receives a call (see Setting up
an intent filter to receive calls). This is the registration step:
Intent intent = new Intent();
intent.setAction("android.SipDemo.INCOMING_CALL");
PendingIntent pendingIntent = PendingIntent.getBroadcast(this, 0, intent, Intent.FILL_IN_DATA);
mSipManager.open(mSipProfile, pendingIntent, null);
Finally, this code sets a SipRegistrationListener on the SipManager. This tracks whether the SipProfile was successfully registered with your SIP service
provider:
mSipManager.setRegistrationListener(mSipProfile.getUriString(), new SipRegistrationListener() {
public void onRegistering(String localProfileUri) {
updateStatus("Registering with SIP Server...");
}
public void onRegistrationDone(String localProfileUri, long expiryTime) {
updateStatus("Ready");
}
public void onRegistrationFailed(String localProfileUri, int errorCode,
String errorMessage) {
updateStatus("Registration failed. Please check settings.");
}
When your application is done using a profile, it should close it to free associated objects into memory and unregister the device from the server. For example:
public void closeLocalProfile() {
if (mSipManager == null) {
return;
}
try {
if (mSipProfile != null) {
mSipManager.close(mSipProfile.getUriString());
}
} catch (Exception ee) {
Log.d("WalkieTalkieActivity/onDestroy", "Failed to close local profile.", ee);
}
}
To make an audio call, you must have the following in place:
SipProfile that is making the call (the
"local profile"), and a valid SIP address to receive the call (the
"peer profile").
SipManager object. To make an audio call, you should set up a SipAudioCall.Listener. Much of the client's interaction with
the SIP stack happens through listeners. In this snippet, you see how the SipAudioCall.Listener sets things up after the call is
established:
SipAudioCall.Listener listener = new SipAudioCall.Listener() {
@Override
public void onCallEstablished(SipAudioCall call) {
call.startAudio();
call.setSpeakerMode(true);
call.toggleMute();
...
}
@Override
public void onCallEnded(SipAudioCall call) {
// Do something.
}
};
Once you've set up the SipAudioCall.Listener, you can
make the call. The SipManager method
makeAudioCall takes the following parameters:
SipAudioCall.Listener to listen to the call
events from SipAudioCall. This can be null,
but as shown above, the listener is used to set things up once the call is
established.For example:
call = mSipManager.makeAudioCall(mSipProfile.getUriString(), sipAddress, listener, 30);
To receive calls, a SIP application must include a subclass of BroadcastReceiver that has the ability to respond to an intent
indicating that there is an incoming call. Thus, you must do the following in
your application:
AndroidManifest.xml, declare a
<receiver>. In SipDemo, this is
<receiver android:name=".IncomingCallReceiver"
android:label="Call Receiver"/>.BroadcastReceiver. In SipDemo, this is
IncomingCallReceiver.SipProfile) with a
pending intent that fires your receiver when someone calls the local profile.
android.SipDemo.INCOMING_CALL. To receive calls, your SIP application must subclass BroadcastReceiver. The
Android system handles incoming SIP calls and broadcasts an "incoming
call" intent (as defined by the application) when it receives
a call. Here is the subclassed BroadcastReceiver
code from SipDemo. To see the full example, go to SipDemo sample, which
is included in the SDK samples. For information on downloading and installing
the SDK samples, see
Getting the Samples.
/*** Listens for incoming SIP calls, intercepts and hands them off to WalkieTalkieActivity.
*/
public class IncomingCallReceiver extends BroadcastReceiver {
/**
* Processes the incoming call, answers it, and hands it over to the
* WalkieTalkieActivity.
* @param context The context under which the receiver is running.
* @param intent The intent being received.
*/
@Override
public void onReceive(Context context, Intent intent) {
SipAudioCall incomingCall = null;
try {
SipAudioCall.Listener listener = new SipAudioCall.Listener() {
@Override
public void onRinging(SipAudioCall call, SipProfile caller) {
try {
call.answerCall(30);
} catch (Exception e) {
e.printStackTrace();
}
}
};
WalkieTalkieActivity wtActivity = (WalkieTalkieActivity) context;
incomingCall = wtActivity.mSipManager.takeAudioCall(intent, listener);
incomingCall.answerCall(30);
incomingCall.startAudio();
incomingCall.setSpeakerMode(true);
if(incomingCall.isMuted()) {
incomingCall.toggleMute();
}
wtActivity.call = incomingCall;
wtActivity.updateStatus(incomingCall);
} catch (Exception e) {
if (incomingCall != null) {
incomingCall.close();
}
}
}
}
When the SIP service receives a new call, it sends out an intent with the
action string provided by the application. In SipDemo, this action string is
android.SipDemo.INCOMING_CALL.
This code excerpt from SipDemo shows how the SipProfile object gets created with a pending intent based on
the action string android.SipDemo.INCOMING_CALL. The
PendingIntent object will perform a broadcast when the SipProfile receives a call:
public SipManager mSipManager = null;
public SipProfile mSipProfile = null;
...
Intent intent = new Intent();
intent.setAction("android.SipDemo.INCOMING_CALL");
PendingIntent pendingIntent = PendingIntent.getBroadcast(this, 0, intent, Intent.FILL_IN_DATA);
mSipManager.open(mSipProfile, pendingIntent, null);
The broadcast will be intercepted by the intent filter, which will then fire
the receiver (IncomingCallReceiver). You can specify an intent
filter in your application's manifest file, or do it in code as in the SipDemo
sample application's onCreate() method
of the application's Activity:
public class WalkieTalkieActivity extends Activity implements View.OnTouchListener {
...
public IncomingCallReceiver callReceiver;
...
@Override
public void onCreate(Bundle savedInstanceState) {
IntentFilter filter = new IntentFilter();
filter.addAction("android.SipDemo.INCOMING_CALL");
callReceiver = new IncomingCallReceiver();
this.registerReceiver(callReceiver, filter);
...
}
...
}
To test SIP applications, you need the following:
To test a SIP application: