Chapter 3. Analyzing Service Requirements

This chapter covers the following topics:

• Application/Bandwidth Requirements

• Backup and Resiliency

• Enterprise Segmentation Requirements

• Access Technologies

• Security Requirements

• Multiprovider Considerations

• Extranets

• Case Study: Analyzing Service Requirements for Acme, Inc.

This chapter's objective is to define the Layer 2 to Layer 3 migration requirements that a service provider must deliver for the enterprise customer to perceive the Layer 3 virtual private network (VPN) offering as valuable. This chapter retains the fictional Acme, Inc. as a reference for the overall discussion. This chapter looks at application and bandwidth requirements that help drive services, such as videoconferencing and data collaboration, that are a basis for enterprise loss and jitter targets. The chapter further examines access technologies such as Frame Relay, ATM, time-division multiplexing (TDM), and Metro Ethernet, in addition to the associated quality of service (QoS) concerns from the enterprise customers. Chapters 1 and 2 introduced these technologies, and this chapter describes the applications that are commonly used with them. The chapter concludes with a case study on an enterprise organization that migrated from a Layer 2-centric service to a Layer 3-centric service as input to Acme for consideration as it embarks on its own journey.