Summary

In this chapter we have tried to tie the technology subjects listed earlier together. This chapter also provided some insight into the challenges facing decision-makers in designing and building an MPLS network to offer Layer 2 and Layer 3 services. We have seen the VRF-aware services model and discussed in detail the impact of equipment scalability on network scalability. Within bounds, we certainly think an MPLS network can replace the traditional Layer 2 services and, as newer-generation hardware arrives, more of the traditional services can migrate to the converged MPLS network. For example, today circuit emulation services are rarely being carried across an MPLS network. As hardware becomes more robust in retrieving and synchronizing clocks from external, line, or GPS sources, and circuit emulation over IP is standardized, more implementations will be available to carry even the traditional T1 circuits across the packet network, making Layer 1/Layer 2 service more closely resemble traditional networks.

Management tools and techniques have also been evolving rapidly to accommodate the needs of service providers and enterprises. Further evolution of management tools will only make the two approaches of L3 provisioning and L2 provisioning and diagnostics more consistent. All these can be deployed today with considerable ease because products are available from Cisco Systems, Inc., and its partners.