About Ethernet Networks

This section presents the concepts used in the design of Switched Ethernet Networks with Point-to-Point links in embedded Ethernet network architectures, typically in automotive, and aeronautical systems.

Notes:

With the Electrical, Electronics and Software Architect (ELAET) and Electrical and Control Architect (EEWCI) roles, you can work with VLANs.
With the Avionics Architect (AVARA) role, you can work with virtual links.

Ethernet Channels

The design of a virtual Ethernet segment (supported by an Ethernet physical channel) is called virtual link in Avionics and Virtual LAN (VLAN) in Automotive and Industrial Equipment.

VLANs

A VLAN (Virtual Local Area Network) is a bus channel with an Ethernet type protocol. A VLAN has an identifier attribute between 1 and 4094, because 0 and 4095 values are reserved.

Virtual Links

A virtual link is a unidirectional logic path from the source end-system (the entry) to all destination end-systems (the exits). A virtual link has an identifier attribute between 0 and 65535. It is associated with an emitter and data are routed on an Ethernet network.

Two types for virtual links can be identified:

Private Virtual Links: A virtual link can be a private virtual link if it connects equipment of the same topology.
Shared Virtual Links: A virtual link can be a shared virtual link if it connects equipment located on different subtopologies. In that case, the entry and exits are located in different subsystems.

Ethernet Physical Segments

An Ethernet physical segment is a point-to-point connection. It is a bus channel with an Ethernet or AFDX/ARINC 664 type protocol. It carries information of VLANs or virtual links.

Ethernet EE Components

EE components used in an Ethernet network, have specific characteristics.

Switches

A switch is an electronic device, which accepts and forwards data frames using any of its ports. The frames are forwarded depending on the MAC (Media Access Control) address contained in the frames. All the ports of the switch are Ethernet ports.

Ethernet Ports

Any EE component can have Ethernet ports. These Ethernet ports have specialized attributes linked to the Ethernet nature of the protocol in the context of the topology. For example, the MAC address of a port may differ if the ECU is inserted in two different topologies.

In the Properties page of a component instance, you can edit Ethernet attributes in a table.

Redundant Ethernet Networks

In Aerospace and Integrated Modular Avionics, networks are digital networks that are redundant. They may not share the same switched and AFDX (Avionics Full-Duplex Switched Ethernet) segments.

Part of the communication definition involves defining networks composed of existing switches and AFDX segments interconnected in the same network.

AFDX routes packets using a virtual link ID, which identifies the carried data, rather than the physical destination.

The definition of the networks helps in designing deterministic and safety compliant separated networks into the same aircraft.

The network commands of the app let you define which subset of a topology constitutes a network, with all its switches and physical Ethernet segments.