Network Technology: Multiprotocol Label Switching
MPLS began life as a way for routers to short-cut the time-consuming process of treating each packet independently, looking up the target IP address each and every time. In an MPLS network, the ingress router does a standard lookup and assigns a numeric label to the packet. Core routers then examine the label and forwards the packet according to the label. All packets with the same label are forwarded the same way. This relieves the core routers of much processing, making the overall network more efficient.
Because the labels are just numbers, they can be assigned according to any criteria the router software supports. Some examples of MPLS applications, in addition to basic IP destination-based routing, include
- VPN membership
- QoS
- Traffic Engineering
- Emulation of any Layer-2 technology
Global Knowledge offers several courses that build understanding of MPLS. They are
- Enterprise Networks over Service-Provider MPLS
- MPLS
- MPLS Traffic Engineering and Other Features
- Advanced Implementing and Troubleshooting MPLS VPN Networks
Resources
- Cisco’s MPLS home page
- Juniper’s MPLS home page
- MPLS-Enabled Applications: Emerging Developments and New Technologies. (Link goes to Amazon.com). This is a mid- to advanced-level practical book on applying MPLS in service-provider and enterprise networks. Highly recommended.
- The MPLS Resource Center
- FutureNet Expo
- Network World – MPLS
- Sprint MPLS VPN Service
- Network Virtualization – Path Isolation Design Guide
MPLS Course Resources
- Dynagen configuration file for the MPLS labs
- An MPLS Troubleshooting Scenario
- The startup configuration for the P1 router used in the last lab.
