BCBs and BEBs

Table 1. Fabric Mode product support
Feature	Product	Release introduced
Fabric BCB mode	5320 Series	Fabric Engine 8.6
	5420 Series	VOSS 8.4
	5520 Series	VOSS 8.2.5
	5720 Series	Fabric Engine 8.7
	7520 Series	Fabric Engine 8.10
	7720 Series	Fabric Engine 8.10
	VSP 4450 Series	VSP 4000 4.0
	VSP 4900 Series	VOSS 8.1
	VSP 7200 Series	VOSS 4.2.1
	VSP 7400 Series	VOSS 8.0
	VSP 8200 Series	VSP 8200 4.0
	VSP 8400 Series	VOSS 4.2
	VSP 8600 Series	VSP 8600 4.5
	XA1400 Series	VOSS 8.0.50
Fabric BEB mode	5320 Series	Fabric Engine 8.6
	5420 Series	VOSS 8.4
	5520 Series	VOSS 8.2.5
	5720 Series	Fabric Engine 8.7
	7520 Series	Fabric Engine 8.10
	7720 Series	Fabric Engine 8.10
	VSP 4450 Series	VSP 4000 4.0
	VSP 4900 Series	VOSS 8.1
	VSP 7200 Series	VOSS 4.2.1
	VSP 7400 Series	VOSS 8.0
	VSP 8200 Series	VSP 8200 4.0
	VSP 8400 Series	VOSS 4.2
	VSP 8600 Series	VSP 8600 6.1
	XA1400 Series	VOSS 8.0.50

The boundary between the core MAC-in-MAC SPBM domain and the edge customer 802.1Q domain is handled by Backbone Edge Bridges (BEBs). I-SIDs are provisioned on the BEBs to be associated with a particular service instance.

In the SPBM core, the bridges are referred to as Backbone Core Bridges (BCBs). BCBs forward encapsulated traffic based on the BMAC-DA.

Important

SPBM separates the payload from the transport over the SPBM infrastructure. Configure all virtualization services on the BEBs at the edge of the network. There is no provisioning required on the core SPBM switches. This provides a robust carrier grade architecture where configuration on the core switches never needs to be touched when adding new services.

A BEB performs the same functionality as a BCB, but it also terminates one or more Virtual Service Networks (VSN). A BCB does not terminate any VSNs and is unaware of the VSN traffic it transports. A BCB simply knows how to reach any other BEB in the SPBM backbone.