Junos

Juniper Junos based on FreeBSD kernel.

Junos Operating System Architect

Junos Operating System Architect includes two components: Routing Engine (RE) and the packet forwarding engines (PFE)

The Routing Engine (RE) runs Junos Software, which includes the FreeBSD kernel, and the software processes, that is, daemons. Junos includes these key user daemons:

• Device control daemon (DCD)
• Routing protocol daemon (RPD)
• Chassis daemon (chassisd)
• Management daemon (MGD)
• Traffic sampling daemon (sampled)
• Automatic protection switching daemon (APSD)
• Simple network management protocol daemon (SNMPD)
• System logging daemon (syslogd)

The Packet Forwarding Engine performs Layer 2 and Layer 3 switching, route lookups, and rapid forwarding of packets. Connected to the Routing Engine by an Ethernet cable, the PFE includes the backplane (or midplane), Protocol Field Compression (PFC), physical interface cards (PICs) and the control board (switching/forwarding), and it has a central processing unit (CPU) that runs the microkernel.

Links

• http://demand-juniper.net/junos/
• http://docs.huihoo.com/junos/