Information Technology Reference
In-Depth Information
Ta b l e 7- 2
Benefits of Ethernet Handoffs at the Customer Edge
Benefit
Description
Seamless enterprise
integration
Ease of integration with existing LAN network equipment
Virtual Private LAN Services
Virtual Private LAN Services (VPLS) defines an architecture that enables Ethernet Multi-
point Service (EMS) over an MPLS network. The operation of VPLS allows for connecting
L2 domains over IP/MPLS network, which emulates an IEEE Ethernet bridge.
Figure 7-4 depicts a VPLS topology in an MPLS network.
VPLS is an Architecture
MPLS Provider Network
CE Router
PE Router
PE Router
CE Router
PE Router
CE Router
Figure 7-4
VPLS Topology Example
VPLS is a type of VPN that allows for the connection of multiple sites into a single L2
domain over a managed IP/MPLS network. VPLS presents an Ethernet interface, which
simplifies the LAN/WAN demarc for service providers. This enables rapid and flexible
service provisioning because the service bandwidth is not tied to the physical interface.
All the VPLS services appear to be on the same VLAN regardless of physical location in
the WA N .
VPLS uses edge routers that learn L2 domains, bridges them, and replicates them through
the VPN. Within the IP/MPLS cloud is a collection of full-mesh connections providing
any-to-any connectivity between sites. VPLS supports many of the new applications and
services need to be on the same L2 network to function properly. Some services lack net-
work layer addressing or are transparent to the upper-layer protocols.
MPLS
MPLS is a technology for the delivery of IP services using an efficient encapsulation
