Yes, You can use native dialer to make sip calls.
For that you need to add one BroadcastReceiver
class...like below...
public class Dialer extends BroadcastReceiver
{
@Override
public void onReceive(Context context, final Intent intent) {
if (intent.getAction().equals("android.intent.action.NEW_OUTGOING_CALL")) {
String phoneNumber = intent.getExtras().getString( "android.intent.extra.PHONE_NUMBER");
// Call some function from here to make SIP Call using this phoneNumber.
// Use this "phoneNumber" to your sip application & setResultData null.
setResultData(null);
}
}
You need to add <intent-filter>
to your AndroidManifest.xml
<receiver android:name=".Dialer" android:enabled="true">
<intent-filter>
<action android:name="android.intent.action.NEW_OUTGOING_CALL" />
</intent-filter>
</receiver>