Matter architecture

Matter defines an application layer on top of the IPv6-based transport protocols. This allows for routing messages regardless of the underlying physical and link layers.

Matter architecture overview

Stack architecture overview

The Matter application layer can be broken down into several main components, as shown on the following diagram.

Matter stack overview

At its lowest layer, the Matter stack interacts with the Transport layer. The payload flows down the protocol stack on the transmitting device and up the protocol stack on the receiving device.

Application

The Application layer defines the business logic for a given end product. For example, for a door lock application, the business logic could be opening and closing a specific model of the door bolt in reaction to a voice command from a specific virtual assistant technology. It could also define input from a specific PIN keyboard UI, reaction on a specific LED on the door bolt model, and so on.

Data Model

The Data Model layer describes how to separate data into abstract logical blocks that help maintain the application in a comfortable manner. The layer operates regardless of the business logic, and so for example it is identical for each door lock type of device.

Data Model layer overview

For more information about the Data Model, see Matter Data Model and device types.

Interaction Model

While the Data Model layer describes abstraction for handling data, the Interaction Model defines how to exchange this data between nodes through interactions.

The Interaction Model layer defines what interactions can be performed between a client and a server device. The node that initiates the interaction is called initiator (typically, a client device), and the node that is the destinatary of the interaction is called target (typically, a server device).

Action Framing

The Action Framing layer transforms messages that are part of interactions from the Interaction Model into serialized binary packets.

Security

The Security layer takes the encoded frames from the Action Framing layer, encrypts them and appends them with a message authentication code.

Message Framing and Routing

This layer is responsible for composing the payload with required and optional header fields. These header fields specify both the properties of the message and its logical routing information.

Transport and IP Framing

This layer manages the transmission of the payload through the IP network to the peer device. It uses either the Transmission Control Protocol (TCP) or the combination of User Datagram Protocol (UDP) with Matter’s Message Reliable Protocol (MRP). During the commissioning process, Bluetooth Transport Protocol over Bluetooth LE can be used instead of that layer.