Design Reference

Glossary
Backbone Core
Bridge (BCB)
Backbone Core Bridges (BCBs) form the core of the SPBM network. The
BCBs are SPBM nodes that do not terminate the VSN services. BCBs
forward encapsulated traffic based on the Backbone MAC Destination
Address (BMAC-DA). A BCB is unaware of the VSN traffic it transports.
A BCB simply knows how to reach any other Backbone Edge Bridges
(BEBs) in the SPBM backbone.
Backbone Edge
Bridge (BEB)
Backbone Edge Bridges (BEBs) are SPBM nodes where Virtual Services
Networks (VSNs) terminate. BEBs handle the boundary between the
core MAC-in-MAC Shortest Bath Bridging MAC (SPBM) domain and the
edge customer 802.1Q domain. A BEB node performs 802.1ah MAC-in-
MAC encapsulation and decapsulation for the Virtual Services Network
(VSN).
Backbone MAC
(BMAC)
Provider Backbone Bridging (PBB) MAC-in-MAC encapsulation
encapsulates customer MAC addresses in Backbone MAC (BMAC)
addresses. MAC-in-MAC encapsulation defines a BMAC-DA and
BMAC-SA to identify the backbone source and destination addresses.
The originating node creates a MAC header that SPBM uses for delivery
from end to end. As the MAC header stays the same across the network,
no need exists to swap a label or do a route lookup at each node, allowing
the frame to follow the most efficient forwarding path end to end. In
Shortest Path Bridging MAC (SPBM), each node has a System ID, which
is used in the topology announcement. This same System ID also serves
as the switch Backbone MAC address (B-MAC), which is used as the
source and destination MAC address in the SPBM network.
Backbone VLAN
identifier (B-VID)
The Backbone VLAN identifier (B-VID) indicates the Shortest Path
Bridging MAC (SPBM) B-VLAN associated with the SPBM instance.
bit error rate (BER) The ratio of the number of bit errors to the total number of bits transmitted
in a specific time interval.
Connectivity Fault
Management
(CFM)
Connectivity Fault Management is a mechanism to debug connectivity
issues and to isolate faults within the Shortest Path Bridging-MAC
(SPBM) network. CFM operates at Layer 2 and provides the equivalent
of ping and traceroute. IEEE 802.1ag Connectivity Fault Management
(CFM) divides or separates a network into administrative domains called
Maintenance Domains (MD).
coarse wavelength
division
A technology that uses multiple optical signals with different wavelengths
to simultaneously transmit in the same direction over one fiber, and then
separates by wavelength at the distant end.
Network Design Reference for Avaya VSP 4000 February 2014 157