Definitive MPLS Network Designs [Electronic resources] نسخه متنی

Chapter 6. Large Enterprise Design Study

This chapter is devoted to the study of a fictitious large European holding of banks called EuroBank. EuroBank was initially a large bank called MainBank in the United Kingdom (UK). Several years ago it acquired EnterBank, a bank in the UK that specialized in providing services to business customers. It also acquired a small insurance company called UK Insurance (UKI), which provided services for consumers and enterprises. EuroBank continued its expansion into other parts of Europe via acquisitions of local banks in Germany (GerBank) and Spain (SpainBank) that had a national branch network. Spainbank also owned two offices in Germany.

Recently, EuroBank acquired a brokerage office in New York City because of its proximity to the New York Stock Exchange. EuroBank's presence in the U.S. is currently limited to that brokerage office, and no banking services are offered at this location. EuroBank plans to continue its expansion via internal and external growth (through acquisitions in other countries).

From a networking perspective, EuroBank's primary objective was to consolidate its multiple subsidiary networks into a single infrastructure to achieve significant cost reductions and enhance communications through a higher-speed network. While doing so, a paramount requirement for EuroBank was to provide strict isolation between its various subsidiaries because each of them operates in strict autonomy. For example, an EnterBank branch location in the UK should not be able to establish any connectivity with a branch location from UKI, and vice versa. In other words, EuroBank needed to support the various subsidiaries in separate partitions. It chose to achieve this through the use of Layer 3 network-based Virtual Private Network (VPN) technology.

More recently, EuroBank decided to take advantage of the chosen VPN technology to also enforce isolation between various departments within one of its subsidiariesMainBank. For example, MainBank's accounting department should not have any connectivity with the brokerage service, and vice versa.

EuroBank has a number of data centers. Unlike the intersubsidiary connectivity requirements, each data center needs to be accessed by all the subsidiaries of the EuroBank group, because they host applications from all the subsidiaries/departments. More specifically, some servers are dedicated to specific subsidiaries/departments, whereas other servers must be accessed by all the locations of EuroBank. Furthermore, communication is needed between different data centers (for example, for backup between servers located in different data centers).

EuroBank took advantage of the transition to a more advanced IP infrastructure to migrate its telephony and video applications to this IP infrastructure to achieve the cost reduction objectives it was pursuing. EuroBank elected to outsource its telephony to a telephony service provider (TSP) offering a complete managed voice over IP (VoIP) service. This includes installation and operation of IP phones and all the necessary call processing devices on EuroBank premises.

Because of the mission-critical applications as well as these voice and video applications now carried over the IP network, tight quality of service (QoS) and reliability were absolutely required while keeping bandwidth costs down. Moreover, new emerging applications requiring more flexibility in terms of voice/data integration for various banking applications (for example, click-to-talk applications or monitoring of remote equipment by video over IP) reinforced these requirements.

The objective of this chapter is to discuss the current EuroBank network design, which is illustrative of a large Enterprise that has deployed its own MPLS infrastructure. In particular, this chapter reviews how the Managed Voice Service integrates and operates in EuroBank's network. Also, because the TSP uses the Layer 3 MPLS VPN technology as a building block in its own infrastructure to implement EuroBank's Managed Voice Service for different customers, this chapter briefly discusses the Layer 3 MPLS VPN design used by the TSP.

It is worth noting that the network design presented in this chapter also applies to many other industry sectors, such as insurance, energy, and manufacturing. Indeed, such companies generally share similar requirements in terms of cost reduction by servicing all their subsidiaries over a single network infrastructure. They also have requirements for secure and controlled communication between different subsidiaries and departments in a given business, as well as integration of telephony services over the shared network. The same challenges are also often faced as a result of the dynamics of mergers, acquisitions, and international expansion.