Basic Concepts; Evb Working Mechanism - H3C S10500 Series Configuration Manual

Basic concepts

Figure 2 shows the components on the EVB station and EVB bridge.
Figure 2 EVB architecture
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Edge Relay—An ER transfers packets between one URP and one or more DRPs. An ER has
one or more DRPs and one URP. Both URP and DRPs are called ER ports. An EVB station can
have multiple ERs.
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S-channel—A point-to-point S-VLAN established between a Port-mapping S-VLAN component
in an EVB station and a Port-mapping S-VLAN component in an EVB bridge. An S-channel
corresponds to the URP of an ER. On an EVB bridge, the end point of an S-channel is known as
an S-channel interface. An S-channel is identified by the S-VLAN Identifier (SVID) and the
S-channel Identifier (SCID), and the two values together are called an (SCID, SVID) pair.
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Virtual Station Interface—A VSI is a port on a VM that directly connects to the DRP of an ER.
A VSI is associated with a logical entity called VSI instance, which is identified by the VSI
Instance Identifier (VSIID). A VSI is associated with a virtual interface called VSI interface on
the EVB bridge port to implement VM traffic management and policy configuration. A VSI
interface can be considered a subinterface of an S-channel.
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Reflective Relay—RR is an operation mode in which a received frame on a port that supports
this function can be forwarded out of the same port. The EVB bridge uses this mode to forward
traffic among VMs on an EVB station, as shown in

EVB working mechanism

The following basic concepts describe EVB station and EVB bridge communication:
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S-channel Discovery and Configuration Protocol—CDCP is used to configure S-channels
between stations and bridges. When a station creates or deletes an S-channel, CDCP sends a
CDCP TLV in an LLDP packet that is addressed using the nearest non-TPMR bridge address to
the bridge. The bridge creates or deletes the S-channel.
•
VSI Discovery and Configuration Protocol—VDP manages the association between a VSI
and a station-facing bridge port (SBP) on a bridge. VDP uses the Edge Control Protocol (ECP)
to carry VDP TLVs. A VDP TLV contains the VSIID, VSI type, and VSI version. The bridge uses
the VSI interfaces to manage traffic for VMs.
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VSI manager—A VSI manager stores network policies such as VSI traffic management and
deploys the policies when a VM accesses the network.
When a station creates a VM, it sends a VDP pre-associate, pre-associate with resource
reservation, or associate packet to the bridge. The bridge sends the request to a VSI
manager, and the VSI manager notifies the bridge to create a VSI interface and apply
policies.
Figure 2.
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