This time, the interoperability evaluation focused the transport of differentiated services a multi-vendor MPLS backbone supporting MPLS traffic engineering.

Based on the guaranteed backbone transport, multi-vendor MPLS virtual private networks (VPNs) were established to demonstrate that VPNs can benefit from the enhanced backbone services.

The following section describes the test plan in detail. Results are documented on page 5.

Agilent Technologies

Alcatel

Avici Systems

Cisco

IXIA

Marconi

Native Networks

Navtel Comm.

Nortel Networks

RAD Data Communications

Riverstone

Tellabs

MPLS Traffic Engineering And Differentiated Services - The MPLS & Frame Relay Alliance test plan mpls2003.149.03 was used for this section.

The tests asked to enable OSPF-TE routing and to ensure full-mesh exchange of dynamic routes in the MPLS backbone. Based on a network-wide agreed per-hop behavior configured on each device, multi-vendor constraint-based MPLS tunnels should be established using the signalling protocol RSVP-TE and the relevant extensions for MPLS Diff-Serv.

Next, transport of emulated application traffic in the Diff-Serv classes Assured Forwarding (AF), Expedited Forwarding (EF) and Best Effort classes should be configured at the label edge routers. A mapping between per-hop behaviors and experimental bit settings (PHB-EXP mapping) was required; the correct prioritization of the per-hop behavior at the MPLS layer during congestion at ingress, transit, and egress MPLS routers should be ensured by sending traffic and creating congestion points at ingress and transit MPLS routers.

There are two different options for the creation of constraint-based label switched paths: The E-LSPs where the per-hop behavior is inferred from the experimental bit setting in each labeled packet, and the L-LSPs where each per-hop behavior group of traffic uses its own label switched path. The test plan focused both E-LSPs and L-LSPs, depending on vendor support.

The last test cases dealt with real constraint-based routing. Since OSPF-TE continuously updates information about the reserved bandwidth in the MPLS backbone network, it is possible to calculate best routes at the ingress label edge router based on the current network usage. The ability of MPLS routers to explicitly select a route based on traffic class and reserved bandwidth, and to establish a label-switched path using this route, was verified in this section.

Virtual Private LAN Service (VPLS) and Ethernet Point-to-Point VPNs - The MPLS & Frame Relay Alliance test plans mpls2003.091.00 and mpls2003.092.00 were used for the tests in this section. They covered:

• Label Binding Distribution via targeted LDP sessions between the provider edge routers
• Data encapsulation of Ethernet and tagged Ethernet frames
• Data encapsulation of ATM and Frame Relay frames
• VPLS service establishment by label exchange between provider edge routers
• Data forwarding to unknown and known Ethernet addresses
• Path tear down and withdraw between provider edge routers

Since VPLS is basically a multipoint extension of point-to-point Ethernet pseudowire links, the tests for point-to-point evaluation were used as a prerequisite for the VPLS tests.

The test plan requested that the transport tunnels were established using the signalling protocol RSVP-TE in order to benefit from the traffic engineering and Diff-Serv processing in the backbone.

In addition to regular Ethernet traffic, the Ethernet pseudowire tunnels also effectively transported TDM emulated traffic (data and voice) using TDMoMPLS technology.

BGP/MPLS VPNs - The MPLS & Frame Relay Alliance test plans mpls2002.049.01 was used for this section.

This test area was aimed at determining the level of interoperability that can be achieved between RFC2547bis implementations of the various vendors. First, VPN establishment between PE devices was tested. The Layer 3 VPN tests, based on the RFC2547bis draft standard covered:

• Full-mesh Multi Protocol BGP (MP-BGP) peering
• MPLS signalled tunnels between provider edge (PE) routers, using the Label Distribution Protocol (LDP)
• Dynamic backbone routing with OSPF including traffic engineering extensions (OSPF-TE)
• Dynamic route propagation using BGP or OSPF between customer edge routers (CE) and provider routers (PE) and also between the PE routers themselves.

Similar to the Ethernet VPN area, the test plan requested that the transport tunnels were established using the signalling protocol RSVP-TE in order to benefit from traffic engineering and Diff-Serv processing in the backbone.