Virtual Private Lan Service - Zte ZXR10 8900 Series User Manual

ZXR10 8900 Series User Manual (MPLS Volume)
data between two PE routers. At the same time, direct process
of LDP label distribution protocol is also defined between two PE
routers to transmit virtual link information. Among them, dis-
tributing VC Label through matching VCID is critical.
When data packet enters PE router at the port of Layer 2 transpar-
ent transmission, PE router finds the corresponding Tunnel Label
and VC Label through matching VCID. PE router will put two layers
labels on the data packet. External layer is Tunnel Label indicat-
ing the route from this PE router to destination PE router. Inter-
nal layer is VC Label indicating which corresponding router port of
VCID belongs to on destination PE router.
PE router should monitor Layer 2 protocol state at each port, such
as frame-relay LMI and ILMI of ATM. When a fault occurs, users
can cancel VC Label through LDP label distribution protocol process
so that Layer 2 transparent transmission is shut off avoiding pro-
ducing unidirectional unwanted data stream.
Such Layer 2 transparent transmission based on MPLS changes
traditional confinement that Layer 2 link should be implemented
through network switch. It essentially forms a pattern of One Net
Multi-Service pattern and makes the operator provide Layer 2 and
Layer 3 Services simultaneously in a MPLS net.

Virtual Private LAN Service

Virtual Private LAN Service (VPLS) allows service providers to de-
liver VPN services based on Ethernet with the same level of support
and reliability as existing services such as Frame Relay and ATM.
VPLS combines the cost-effectiveness of Ethernet with the ser-
vice delivery, traffic engineering, scalability and reliability of Multi
Protocol Label Switching (MPLS) to provide a multipoint Layer 2
Ethernet VPN service.
VPNs are a value-added premium service that a service provider
can offer to its business customers. VPNs allow service providers
to connect multiple customer sites together securely over a
common shared network. The service keeps individual customer
data private from other customers' data using virtual connections
across the shared network. Traditionally, VPNs are based on
leased lines, Frame Relay, or ATM services, but more recently on
Ethernet, IP and Multi Protocol Label Switching (MPLS).
VPNs are major source of revenue for service providers as they
provide flexibility, scalability and integrate well with data services.
However, VPNs use traditional bandwidth delivery services to con-
nect to the customer, and are costly to provision and complex to
manage. The continued growth of the Internet and IP-based ser-
vices combined with a move by customers to outsource more IT
functions, such as storage and backup, is placing a strain on these
fixed-bandwidth VPN delivery models.
Ethernet provides simple, flexible, more scalable bandwidth than
traditional fixed bandwidth solutions and has revolutionized Metro
environment. For the end-user, Ethernet is less expensive, eas-
ier to connect and simpler to manage. For service provider, it is
cheaper, more flexible, and allows new services to be provisioned
more simply and quickly than traditional solutions.
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