- What Is MPLS?
- Why Is MPLS Needed?
- How Is MPLS Done?
- When and Where Is MPLS Used?
- Who Is Doing MPLS?
- The Label Switching Paradigm
- A Quick Introduction to MPLS
- Evolution of Internet Network Models
- Basics of the Internet
- Internetworking Technology Basics
- More Basics: Graph Theory and Modeling Language
- The Promise of MPLS
- The Promise of the Promise of MPLS
When and Where Is MPLS Used?
One general model of the Internet is to view the entire set of communicating computers and networks as a set of concentric circles. The inside core routes lots of traffic at very high speeds. Moving outward, various types of traffic that need to flow together somehow move at many different speeds.
It is often said that the Internet is a "dumb" network.6 As shown in Figure 16, the intelligence of the Internet is dispersed to the edges, where very "smart" applications use networking technologies to perform all those amazing things computers are capable of doing. When using the Internet, packet flow begins at one host, travels through the various strata of communication technologies that comprise the Internet, and ends at the destination host.
Figure 16 Internet traffic and devices.
This model relates directly to when and where MPLS is used. MPLS is being deployed first from the core outward as a transport technology. In a sense, it is an attempt to add a new type of internetworking intelligence by introducing more control over how traffic flows and what services can be delivered. The first deployments of MPLS have primarily been by large, top-tier service providers that need more control in how traffic flows through their networks. Naturally, because the communication technologies must all interoperate, there is an ongoing interest by second- and third-tier service providers, metropolitan equipment vendors, and large enterprises to enable MPLS within their networks. As the technology matures, it will gain more use in a variety of important areas, such as TE, VPNs, QoS, packet-based voice services, and various optical-based technologies. MPLS is being viewed as a strong, enabling mechanism for generating revenues for service providers. It is also interesting to note that MPLS in its current form will not migrate to the hosts. It is an Internet technology that is transparent to the end-user and will reside within the internetworking infrastructure.