ARINC 664 Part 7 is an ARINC specification defining a deterministic Ethernet network used for next generation aircraft that utilizes commercial off-the-shelf products to reduce costs and development time. AFDX is a specific implementation of ARINC 664 which stands for Avionics Full Duplex Switched Ethernet.

The physical layer consists of a star topology Ethernet network with End Systems and layer two switches. The defining feature of the network is the use of Virtual Links. A VL defines a logical data path through the shared network. It defines a data flow in one direction from a single source to one or multiple destinations. The VL is identified by 16 bits in the destination MAC address. This is used by the switches to route the frame appropriately.