The EX4400 Series and QFX5120-48YM and ACX5448-M switches share a common architecture and feature set. They implement a variety of high-speed interfaces (only Ethernet is in the scope of the evaluation) for enterprise branch, campus, and data center networks. These switches share common Junos firmware, features, and technology for compatibility across platforms.
The appliances are physically self-contained. Each appliance houses the firmware and hardware necessary to perform all routing functions. The architecture components of the appliances are:
- Switch fabric – the switch fabric boards/modules provide a highly scalable, non-blocking, centralized switch fabric matrix through which all network data passes.
- Routing Engine (Control Board) – the Routine Engine (RE) runs the Junos firmware and implements Layer 3 routing services and Layer 2 switching services. The RE also implements the management functions for configuration and operation of the TOE and controls the flow of information through the TOE, including support for appliance interface control and control plane functions such as chassis component, system management and user access to the appliance.
- Layer 2 switching services, Layer 3 switching/routing services and network management for all operations necessary for the configuration and operation of the TOE and controls the flow of information through the TOE.
- Packet Forwarding Engine (PFE) – The PFE implements all operations necessary for transit packet forwarding. The line cards implement an extensive set of Layer 2 and Layer 3 services that can be deployed in any combination of L2- L3 applications.
- Power – The T-models and the F-model of the EX4400-Series appliances include non-PoE ports whereas the P-Models implement a Power over Ethernet (PoE) interface for powering up the TOE. Power supply bays allow flexibility for provisioning and redundancy. The power supplies connect to the midplane, which distributes the different output voltages produced by the power supplies to the appliance components, depending on their voltage requirements.
The MACsec line cards implement MACsec between adjacent devices, all traffic communicated between the devices including frames for LLDP, DHCP, ARP, STP, Ethernet Control frames, etc (the exceptions to this protection are Destination MAC and Source MAC addresses in MACsec and MKA frames).