MPLS and Next-Generation Networks: Foundations for NGN and Enterprise Virtualization

This section discusses business drivers and requirements that SPs and enterprise organizations use as a framework for service convergence and virtualization via IP/MPLS.

Cost savings and revenue generations are two key drivers that attract service providers to using IP/MPLS as a business opportunity. This business opportunity translates to deploying a global ubiquitous network and to developing services that are based on this technology. Further, as mentioned previously in this chapter, time-to-market deployment possibilities of new services based on MPLS technology are critical for the service provider. Ancillary to this factor is the any-to-any service constructs that one can have with MPLS.

In fact, service providers expect operational savings by deploying new IP/MPLS-based services. Applications once implemented in circuit-based networks, such as voice, are perceived by service providers to be less expensive to deploy over IP. These cost savings come from the opportunity to consolidate multiple infrastructures (PSTN for voice, and video and data over IP). The consolidation can be facilitated by such mechanisms as differentiated class of service (CoS).

Further, service providers are exploring new revenue-generating service offerings based on IP, such as Voice over IP (VoIP), videoconference streaming, video/web data conferencing, mobility management, or follow-me, to name a few potential enhanced services. Chapter 2 describes these service options for both Layer 2 and Layer 3.

Controlling costs while supporting existing and new services, and transitioning multiple networks to a consolidated packet-based service-aware architecture, such as IP/MPLS, are indeed requirements for service providers.

To summarize the key issue, economy of scale with a focus on a multiservice paradigm for multiple customers over a converged IP/MPLS core is an important requirement for a service provider. The service element resides at the edge of the multiservice transport infrastructure.

Fundamentally, the network edge is where the customer access connections come in and where the service is created as shown in Figure 1-2.

Enterprise Customers

Enterprise customers have invested in applications such as enterprise resource planning (ERP), supply chain management (SCM), and customer relationship management (CRM) that facilitate collaborative workplace processes requiring integration to the corporate LAN. ERP is an industry term for the broad set of activities supported by multimodule application software that helps a manufacturer or other business manage the important parts of its business, including product planning, parts purchasing, maintaining inventories, interacting with suppliers, providing customer service, and tracking orders. ERP can also include application modules for the finance and human resources aspects of a business. Typically, an ERP system uses or is integrated with a relational database system.

SCM is the delivery of customer and economic value through integrated management of the flow of physical goods and associated information, from raw materials sourcing to delivery of finished products to consumers.

CRM is an information industry term for methodologies, software, and usually Internet capabilities that help an enterprise manage customer relationships in an organized way. For example, an enterprise might build a database to store information on its customers and that database could describe relationships in detail. The information could be so detailed, in fact, that management, salespeople, people providing service, and perhaps the customer directly could access information, match customer needs with product plans and offerings, remind customers of service requirements, and know which other products a customer has purchased. Applications such as ERP, SCM, and CRM facilitate workflow collaboration across the enterprise organization.

Large enterprises need efficient solutions to provide real-time access of these applications for their customers who might be geographically dispersed throughout the world and where leased lines and Frame Relay might not be readily accessible or even cost effective. Total cost of ownership (TCO) is an important driver for an enterprise customer when comparing various solutions and alternatives. Enterprise customers are exploring the pros and cons of managing disparate networks that can often lead to high operating costs. Additionally, global reach, quality of service, security, and scalability are drivers toward considering an IP VPN solution based on MPLS.

Enterprise Motivations for Migrating to Layer 3 Services

Why are enterprises migrating to Layer 3 services, particularly those that are based on MPLS? Although traditional factors, such as cost and reliability, are significant, there are new challenges for the enterprises, such as distributed applications and business-to-business communications that facilitate workflow collaboration. MPLS provides the any-to-any solution that is requisite for such applications, as opposed to the complex overlay implementations that are common in Layer 2 networks. Moreover, these applications are IP-based, so an opportunity exists for enterprise organizations to mitigate against protocol complexity. They can do so, for example, by executing a strategy that reduces the protocols to IP for applications.

Security is paramount as companies migrate from Layer 2 to Layer 3 services. Detecting and responding to distributed denial-of-service (DDoS) attacks and providing work containment measures without disturbing global services must be part of the overall security policy. MPLS security is specifically discussed in Chapter 8, "Traffic Engineering."

Business separation, mergers and de-mergers, and acquisitions require an extranet implementation coupled with security. Layer 2 implementations can be complex because of the N*(N-1)/2 challenge. The (N*(N-1)/2 construct is referred to as an overlay model. With an overlay model, there is the associated complexity of deploying a site because for every connection one needs to reconfigure all other sites correspondingly. In contrast with a peer model for extranet, an organization using Layer 3 (that is, Layer 3 MPLS VPN), simply needs to configure the relevant Provider Edge (PE) for a Virtual Private Network (VPN).

Migrating to Layer 3 services must not negatively impact application performance. For example, in determining bandwidth for streaming services, the amount of bulk data transfer/retrieval and synchronization information is approximately <384 Kb/s. A movie clip, surveillance, or real-time video requires between 20 and 384 Kb/s. Bandwidth requirements for conversational/real-time services, such as audio and video applications, include videophone, which is between 32 and 384 Kb/s; Telnet, which is about <1 KB; and telemetry, which is approximately <28.8 Kb/s. Table 1-1 depicts application performance examples for conversational and real-time services.

^[**] Exact values depend on specific codec, but assume use of a packet loss concealment algorithm to minimize the effect of packet loss.

^[*] Assumes adequate echo control.

Finally, service providers tend to bundle, meaning propose multiple services with a target to prevent customer churn. An example is triple play, in which voice, data, and video can be offered as a bundle perhaps over a single transport link. Bandwidth requirements for cable modem can be approximately 1 Mb upstream to the provider and 3 Mb downstream to the subscriber. One could additionally have prioritized traffic for VoIPtwo VoIP phone lines, per-call charging, and broadcast video MPEG 2and one half D1, with one channel per set-top.

To summarize, IT managers must continually manage costs and maintain reliable WAN infrastructures to meet their business goals. Success in today's business climate also depends on the ability to overcome a more complex set of challenges to their corporate WANs. Enterprise IT managers are faced with and require a solution that will address the following factors:

• Geographically dispersed sites and teams that must share information across the network and have secure access to networked corporate resources.

• Mission-critical distributed applications that must be deployed and managed on a network-wide basis. Further, IT managers are faced with a combination of centralized, hosted applications and distributed applications, which complicates the management task.

• Security requirements for networked resources and information that must be reliably available but protected from unauthorized access.

• Business-to-business communication needs, both to users within the company as well as extending to partners and customers. QoS features that ensure end-to-end application performance.

• Support for the convergence of previously disparate data, voice, and video networks resulting in cost savings for the enterprise.

• Security and privacy equivalent to Frame Relay and ATM.

• Easier deployment of productivity-enhancing applications, such as enterprise resource planning (ERP), e-learning, and streaming video. (These productivity-enhancing applications are IP-based, and Layer 2 VPNs do not provide the basis to support these applications.)

• Pay-as-you-go scalability as companies expand, merge, or consolidate.

• Flexibility to support thousands of sites.

MPLS provides the any-to-any connectivity, ensures separation of organizations, functions by supporting the concept of VPN, provides security due to its inherent VPN capabilities, and supports QoS mechanisms.

Chapter 15, "The Future of MPLS," examines several case studies with return on investment (ROI) models that explore alternatives to deploying and subscribing to MPLS-based services. For a detailed view of the business implications in deploying IP-based services, please refer to the following book on the topic: Developing IP-based Services: Solutions for Service Providers and Vendors, by Monique Morrow et al., ISBN: 155860779X.