Brocade Multi-Service IronWare Switching Configuration Guide (Supporting R05.6.00) - Manual (Page 254)

224 Multi-Service IronWare Switching Configuration Guide
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Ethernet Service Instance (ESI) overview
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Once an ESI is defined, Brocade NetIron CES and Brocade NetIron CER devices operate on rules for
configuring VLANs inside an ESI, and check against configuration incompatibilities (such as
configuring the same VLAN value from two different ESIs on the same port).
Types of ESI
There are two types of Ethernet Service Instances, as described:
Default ESI
In Figure 19 , VLANs associated with ports in the top left corner of the Brocade NetIron CES and
Brocade NetIron CER devices aren't being transported over to the carrier network - these VLANs are
being locally switched and connected with switches in the local area network. The Brocade NetIron
CES and Brocade NetIron CER devices support 4K VLANs of this type, without any ESI configured.
Internally, these VLANs are associated with a Default ESI, and are referred to as 'Regular VLANs'.
Customer ESI
ESIs that are configured to hold customer VLANs that need to be transported across a carrier
network are usually referred to as customer ESIs. A customer ESI always has a Layer 2 protocol
VLAN encapsulation applied to all VLANs in the ESI.
In a carrier network, an incoming customer VLAN packet will usually be configured with successive
encapsulations, such as with service VLANs, in-service identifiers, or backbone VLANs. Each
encapsulation is associated with a different ESI. To define the encapsulation hierarchy, an ESI for
an incoming packet is defined as a client of the ESI for the next encapsulation. The next
encapsulation ESI is referred to as a 'provider ESI' and the ESIs that are declared as client ESIs are
referred to as 'client ESIs'.
Depending on their association, customer ESIs can be one of the three types:
• Standalone ESI - An ESI that is not linked to any other ESI, and are used only to hold VLANs and
define their properties.
• Provider ESI - An ESI with one VLAN, and one or more client ESIs, each holding one or more
VLANs.