MPLS-Enabled Applications: Emerging Developments and New Technologies

15.7. MPLS IN THE ENTERPRISE

The focus of this book has been the use of MPLS by service providers to offer services to enterprise customers, as this is the main way in which MPLS is used today. However, an emerging trend is for larger companies to use MPLS as part of their own internal network infrastructure. Such an enterprise treats its network as a mini version of a service provider network, providing services to the various departments within the company. In some cases, there is a requirement for data separation between certain areas of the company. For example, some financial institutions have sensitive areas that should not be accessible from the company in general, or may need to maintain internal walls between different business units or subsidiaries for reasons of client confidentiality or avoiding conflicts of interest. A typical model is to use Layer 3 VPNs, to constrain the connectivity between different departments, while still having the ability to have shared resources accessible from all the departments that require it. This model is illustrated schematically in Figure 15.5.

Figure 15.5. Use of Layer 3 VPN in an enterprise network

While the actual routers used may be smaller in capacity than those used in service provider networks, the principles remain the same, with P routers that perform MPLS forwarding without awareness of the routes carried within each VPN, ...