Juniper Acronyms

This is a list of acronyms that I come across while reading Juniper documentation. Most should be Juniper-specific, but some may not.

ASIC
Application-Specific Integrated Circuit
BERT
Bit Error Rate Test
dcd
Device Control Daemon: One of the JUNOS daemons running on the Routing Engine. Handles configuration and maintenance of the interfaces.
FEB
Forwarding Engine Board: a type of Switching Control Board, found on some devices like M5, M10.
FPC
Flexible PIC Concentrator, the component that joins multiple PICs on devices that require more than one. In the JUNOS interface naming convention Type-FPC/PIC/Port.Unit, the FPC is the first all-numeric component. For example, interface fe-1/2/3 is on FCP 1 on the device.
LDP
Label Distribution Protocol. One of the sources of routes in the routing table, with a preference value of 9.
mgd
Management Daemon: One of the JUNOS daemons running on the Routing Engine. Manages user access to the device.
MMB
Memory Mezzanine Board: a type of Switching Control Board found on some devices like the T320 and the T640. It is integrated in the FPC.
MSDP
Multicast Source Discovery Protocol. One of the sources of routes in the routing table, with a preference value of 175.
PFE
Packet Forwarding Engine: the second part of the Control Plane / Forwarding Plane separation on Juniper devices. This part of the device is mostly hardware.
pfed
Packet Forwarding Engine Daemon: One of the JUNOS daemons running on the Routing Engine. Manages the communication between the Routing Engine and the Packet Forwarding Engine.
PIC
Physical Interface Card. Different types of PICs exist, to offer difference connectivity capabilities, for example there are ATM PICs, or SDH PICs, which consequently contain different ASICs. In the JUNOS interface naming convention Type-FPC/PIC/Port.Unit, the PIC is the second all-numeric component. For example, interface fe-1/2/3 is on PIC 2 on the device.
PIM
Protocol Independent Multicast. One of the sources of routes in the routing table, with a preference value of 105.
RE
Routing Engine, the first part of the Control Plane / Forwarding Plane separation on Juniper devices. This part of the equation is mostly software. It contains the OS, and this is where the configuration takes place. Physically, it looks like a small PC, with a motherboard, processor, RAM and storage. Some devices have dual REs for redundancy.
RSVP
Resource Reservation Protocol. One of the sources or routes in the routing table, with a preference value of 7.
rpd
Routing Protocol Daemon: One of the JUNOS daemons running on the Routing Engine. Handles exchange of routing messages, maintenance of routing table, enforcement of routing policies.
RPF
Reverse Path Forwarding is the process used by Junos to populate the inet.2 routing table, used by the router to prevent routing loops in multicast routing protocols.
SCB
System Contol Board: a type of Switching Control Board, found on some devices like the M40.
SFM
Switching and Forwarding Module: a type of Switching Control Board, designed so that devices will have two SFMs. Some devices, like the M40e, use the SFMs in Active/Passive mode, whereas others, like the M160, use both in Active/Active mode.
SSB
System Switching Board: a type of Switching Control Board, found on some devices line the M20. It is designed so that devices will contains two SSBs, in Active/Passive redundancy.
SSRAM
Synchronized Static Random Access Memory. It is a component of the Switching Control Board, and it contains the routing table, pushed to it by the Routing Engine.
SCB
Switching Control Board. This is the heart of the Packet Forwarding Engine. Similarly to the Routing Engine, it contains a processor and RAM, but the purpose of those are to coordinate the operation of the rest of the components of the PFE, rather than actually participating in routing/forwarding decisions.
TED
Traffic Engineering Database