The previous chapters discussed the theory and configuration of the MPLS architecture within a Frame-mode and Cell-mode implementation. Now that this theory is clear, we should consider a case study that provides a migration example for both a router and an ATM-based backbone so that we can put the theory into practice.
Although this chapter provides a suggested basic migration path, this does not mean that other approaches cannot be taken or that all relevant topics are covered. For instance, we will not consider network management or accounting because both of these areas are too broad for meaningful discussion within this chapter. However, you should be aware that each of these topics should be fully investigated before migration. We will look at network management in some detail in chapters that follow and explore some suggested techniques to assist in successful deployment within an MPLS environment, especially in the case where advanced services such as virtual private networks are used. In the case of IP accounting, you should be aware that tools such as NetFlow work purely on IP packets, not MPLS packets. This means that care must be taken to enable these tools on interfaces that will receive IP packets so that accounting of customer traffic is successful.