Does Firebase Cloud Messaging support VOIP pushkit services?

Does anyone has an idea about Firebase Cloud Messaging support VOIP pushkit services.

If yes then can someone please do provide guidelines for same.

Same thing which is implemented in Skype / Hangout / WhatsApp or any other VOIP based apps.

Thanks in advance.

What are the two types of messages in Firebase Cloud Messaging?

Using Firebase Cloud Messaging, we can send three types of messages, i.e., Notification Message, Data Message, and the message with both Notification & Data Payload.

What protocol does FCM use?

FCM (Firebase Cloud Messaging) uses HTTP and XMPP Server Protocol serving JSON and Plain Text both.

What is Firebase Cloud Messaging used for?

Firebase Cloud Messaging (FCM) provides a reliable and battery-efficient connection between your server and devices that allows you to deliver and receive messages and notifications on iOS, Android, and the web at no cost.

At time of writing (FirebaseMessaging 1.1.0/Firebase 3.2.0) FCM uses regular APNs underneath on iOS, so there isn't support for PushKit notifications.