Lucent Technologies CBX 3500 - Configuring a PWE3 Circuit

Beta Draft Confidential
9-641/19/05 ATM Services Configuration Guide for CBX 3500, CBX 500, GX 550, and B-STDX 9000
Configuring ATM Over MPLS Gateway Solution on CBX 3500
Configuring PWE3 Over MPLS Core Network
Configuring a PWE3 Circuit
PWE3 circuits enable carriers to offer scalable and flexible Layer 2 VPNs over an
IP/MPLS backbone, using PWE3 drafts and standards. Using Pseudo Wire
Edge-to-Edge Emulation standards, the PWE3 circuit is created between two LERs on
the edge of the IP/MPLS network. Existing native Layer 2 connections to a service
provider may remain, but instead of data being carried over an ATM or Frame Relay
service, the traffic is encapsulated and routed over the provider’s common IP/MPLS
backbone.
The Layer 2 VPNs are based on an implementation where ATM Layer 2 circuits are
tunneled to an MPLS LSP. These Layer 2 MPLS VPN circuits do not use VNN
routing. They depend solely on PW setup procedures using Label Distribution
Protocol (LDP) operating in downstream unsolicited liberal label retention mode.
LDP defines the set of procedures and messages by which Label Switched Routers
(LSRs) establish Label Switched Paths (LSPs) through a network by mapping
network-layer routing information directly to datalink layer switched paths.
The PWE3 circuit endpoints must be ATM UNI DCE or DTE or Frame Relay.
PWE3 supports:
• A total of 64K Layer 2 MPLS VPNs/PWE3 PVCs per CBX 3500 switch
• The following QoS types:
– CBR
– VBR-rt
– VBR-nrt
–ABR
–UBR
• Static as well as signaled PWE3 PVCs
• Statistic collection, per-PWE3 PVC and per-LPort
Before the PWE3 circuit can be created, the PSN tunnel between the two LERs must
be configured and up. This can either be a bi-directional PSN tunnel or two
unidirectional tunnels (in a Lucent network) or a unidirectional tunnel (to a third party
network).
To configure a PWE3 circuit:
1. See “Defining a Point-to-Point Circuit Connection” on page 10-13 and follow
step 1 through step 6 to begin the PVC configuration.
2. See “About the PVC Tabs” on page 10-16 for information on filling in the tabs in
the Add PVC dialog box.