Cisco Systems OL-21636-01 Security Camera User Manual


 
E-11
Cisco IP Solution Center L2VPN and Carrier Ethernet User Guide, 6.0
OL-21636-01
Appendix E ISC Layer 2 VPN Concepts
VPLS Service Provisioning
VPLS can be connected to this VFI. The PE router establishes emulated VCs to all the other PE routers
in that VPLS instance and attaches these emulated VCs to the VFI. Packet forwarding decisions are
based on the data structures maintained in the VFI. All the PE routers in the VPLS domain use the same
VC-ID for establishing the emulated VCs. This VC-ID is also called the VPN-ID in the context of the
VPLS VPN.
For more information, see the following sections:
Multipoint EWS (EP-LAN) for an MPLS-Based Provider Core, page E-11
Multipoint ERS (EVP-LAN) for an MPLS-Based Provider Core, page E-11
Topology for MPLS-Based VPLS, page E-11
Multipoint EWS (EP-LAN) for an MPLS-Based Provider Core
With multipoint EWS (also known as EP-LAN in MEF terminology), the PE router forwards all Ethernet
packets received from an attachment circuit, including tagged, untagged, and Bridge Protocol Data Unit
(BPDU) to either:
Another attachment circuit or an emulated VC if the destination MAC address is found in the L2
forwarding table (VFI).
All other attachment circuits and emulated VCs belonging to the same VPLS instance if the
destination MAC address is a multicast/broadcast address or not found in the L2 forwarding table.
Multipoint ERS (EVP-LAN) for an MPLS-Based Provider Core
With multipoint ERS (also known as EVP-LAN in MEF terminology), the PE router forwards all
Ethernet packets with a particular VLAN tag received from an attachment circuit, excluding BPDU, to
another attachment circuit or an emulated VC if the destination MAC address is found in the L2
forwarding table (VFI). If the destination MAC address is not found or if it is a broadcast/multicast
packet, then it is sent on all other attachment circuits and emulated VCs belonging to the VPLS instance.
The demultiplexing VLAN tag used to identify a VPLS domain is removed prior to forwarding the
packet to the outgoing Ethernet interfaces or emulated VCs because it only has local significance.
Topology for MPLS-Based VPLS
From a customer point of view there is no topology for VPLS. All the CE devices are connected to a
logical bridge emulated by the provider core. Therefore, the CE devices see a single emulated LAN. (See
Figure E-9.)