Definitive MPLS Network Designs [Electronic resources] نسخه متنی

How this Book is Organized

Not every network architect has in-depth knowledge of all the technologies involved in today's networks. Therefore, the first two chapters provide a comprehensive overview of all the technologies used in the various design studies. They focus on the essential concepts, protocols, and more-recent developments. Chapter 1 focuses on the technologies that have the most impact at the edge of the network: Layer 3 VPN, multicast VPNs, IPv6, and pseudowire. Chapter 2 is devoted to QoS, MPLS traffic engineering, and network recovery technologies that are an integral part of modern core networks.

The remaining chapters present a series of design studies. Each one is based on a specific network that is hypothetical but that is very representative of a profile of service providers and enterprise networks running MPLS today.

Each design study chapter has four parts. First, the authors describe the network environment, including the set of supported services, network topology, POP structure, transmission facilities, basic IP routing design, and possible constraints. Next, the objectives that influenced the design are identified. These can include optimizing bandwidth usage, supporting seamless VPN service through a partner service provider, trunking the existing ATM infrastructure over the MPLS core, and offering a rich set of QoS guarantees. Then, each design study details all aspects of the network design, covering VPN, QoS, traffic engineering, network recovery, and, where applicable, multicast, IPv6, and pseudowire. The chapter ends by listing a number of lessons that can be drawn from the design study. This way, all types of service providers and enterprises can adapt aspects of the design solutions to meet their individual network environment and objectives.

Chapter 3 describes a data and long-distance voice service provider in the U.S. (an IXC) that owns fiber and transmission facilities nationwide. In particular, this design study covers Layer 3 VPN design, QoS design based on an overengineered core, and fast recovery over unprotected DWDM transmission facilities.

Chapter 4 describes the design of a national telco deploying a multiservice backbone over which multiple services have been migrated (such as IPv4 Internet and IP VPN services). This network is also used to trunk the domestic public telephony traffic and to introduce new services (such as IPv6 Internet and Carrier's Carrier). Also, this chapter details the use of shared PE routers in which all services are offered on the same devices: a rich CoS offering on the access and QoS/Fast Reroute for telephony traffic in the core.

Chapter 5 describes an international service provider with many POPs all around the globe. This service provider relies on interconnection with regional service providers and establishes tight agreements with them to provide a seamless service for its customers. Also, it has deployed virtual POPs (VPOPs) to establish a point of presence in a particular country without extending its own core network to reach the corresponding parts of the world. The company takes advantage of interprovider MPLS traffic engineering LSPs that offer guaranteed bandwidth and fast recovery through another provider's IP/MPLS network. This chapter contains a detailed design discussion of inter-AS Layer 3 VPNs, including the single-operator case, multioperator case, and multicast. It also describes extensive traffic engineering aspects related to bandwidth optimization, including DiffServ-aware traffic engineering in combination with a rich set of QoS mechanisms. You'll also read about transport of ATM traffic onto traffic engineering LSPs and the VPOP design and its associated traffic engineering, restoration, and QoS operations in an inter-AS environment.

Finally, Chapter 6 describes a large enterprise (a group of banks) relying on Layer 3 VPN services to control communications within and across subsidiaries in an environment where mergers, acquisitions, and expansion in other countries are common. In particular, this design covers the operation of a private international MPLS core in conjunction with branch connectivity provided by other Layer 3 MPLS VPN and Frame Relay service providers. You'll read about the use of IPSec for secure communication across a subset of users with strict security requirements, and QoS over a mix of fast and relatively low-speed links. The chapter also details how a managed voice service operates within this enterprise Layer 3 MPLS VPN design. You'll also see how a telephony service provider uses the Layer 3 MPLS VPN technology inside its own network to offer managed telephony services to multiple customers.