APPLICATION NOTE. Benefits of MPLS in the Enterprise Network

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A P P L I C A T I O N N O T E

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Abstract

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Introduction

The purpose of this paper is to outline the benefits and applications for Multiprotocol Label Switch-ing (MPLS) in enterprise networks. A high-level explanation of MPLS technology is given along with various possible deployment scenarios for MPLS. This paper also describes what an end-to-end solution entails from the core to the data center and edge of the enterprise network.

Market trends and customer issues

Enterprise business expansion

Globalization is forcing enterprises to extend their business reach into different geographic areas that have not been considered before. Now enterprises must link together various sites that are spread across the same city, the same country or across the world.

The types of applications being used by enterprises are also increasing in sophistication and com-plexity. Videoconferencing, social networking sites and customer care systems are being utilized on a regular basis to enhance business operations.

Users in remote locations and branch offices have now come to expect the same user experience as those users situated in corporate headquarters. Applications must be available 24/7 and the network must be able to deliver the applications effectively and efficiently.

All enterprises must be able to operate their business cost effectively by minimizing capital and operating expenses. The network infrastructure should be able to expand and respond to more com-plex network requirements without the need for big build-outs that require a large investment in networking platforms. The network infrastructure also needs to be easy to maintain and configure on a day-to-day basis.

Enterprises need to protect mission-critical data in the network and often need to separate different business divisions for security, policy, economic or political reasons. Without the introduction of MPLS, most enterprises achieved this separation by purchasing multiple WAN links, thus increas-ing bandwidth, maintenance and operatincreas-ing costs.

Enterprises have current investments in their network infrastructure based on older or aging plat-forms and technologies. To address network expansion, complex overlay networks continue to be built, increasing network administration and maintenance costs. Enterprises need a smooth migra-tion path from their existing technologies to new technologies without having to invest heavily in completely new network architectures.

MPLS as a technology can help to solve many of these issues in the enterprise network.

MPLS adoption is on the rise

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IDC Research states that the adoption of IP/MPLS is on the rise, as seen in Figure 1. Figure 1. IDC Voice and Data Services Survey

Other

20 15

Mean %

Source: IDC Voice and Data Services Survey: WAN Technology Usage and Migration Plans, Dec 2007 10 5 25 0 IP VPN (DIY) IP VPN Private line ATM Frame relay 10.4 22.7

Plan to use in 12 months

30 Currently using 1.2 24.8 26.7 19.8 21.0 9.8 21.5 1.2 21.1 19.7 What is MPLS?

MPLS is a framework defined by the Internet Engineering Task Force (IETF) that allows for the introduction of label switching to Layer 2 and Layer 3 protocols. In a traditional routed IP network, each router makes an independent forwarding decision for each packet based solely on the packet’s network layer header. Every time a packet arrives at a router, the router has to make a decision as to where to send the packet.

With MPLS, a label is added to the IP protocol to encapsulate the IP packet and the switching decision at the router is based on the label only and not on the Layer 3 header. In this way, MPLS brings deterministic circuit switching to a packet-based infrastructure, which gives network opera-tors more control over their network. MPLS can also handle packets with particular characteristics (such as those coming from particular ports or carrying traffic of a particular application type) in a consistent fashion. Packets carrying real-time traffic, such as voice or video, can easily be mapped to low-latency routes across the network — something that is challenging with conventional routing. The labels provide a way to introduce additional information to each packet — information above and beyond what the routers had previously.

There are also different types of MPLS such as Virtual Private LAN Services (VPLS), which is a specific type of virtual private network (VPN) for Ethernet. VPLS is used for connectionless proto-cols such as Ethernet and Pseudowire Edge to Edge Emulation (PWE3) for circuit-oriented protoproto-cols like Frame Relay and Asynchronous Transfer Mode (ATM).

Benefits of MPLS

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Benefits of MPLS in the Enterprise Network | Application Note 3 As applications converge onto one network, the enterprise network operator must ensure that all users have the same user experience regardless of whether they are located in a branch office or in corporate headquarters. MPLS supports Quality of Service (QoS), the ability to assign priorities for different applications in the network, thereby allocating the needed network bandwidth at the ap-propriate time.

MPLS and security

With MPLS VPN technology, the enterprise has a viable alternative to the purchasing and pro-visioning of multiple links and circuits. With a single physical network for multiple business divi-sions, enterprises can logically separate these entities and in doing so can guarantee security for the mission-critical data from different entities.

MPLS VPNs allow for a common set of network resources to be shared throughout the entire business without sacrificing security. For example, a common data center can be leveraged throughout the busi-ness, without requiring complex overlay configurations that some other technologies would dictate. Scalability and high availability

Because of the any-to-any connectivity that MPLS offers, network designers can reduce the number of hops between network points, which translates directly to increased response time and improved application performance.

MPLS-based networks also improve disaster recovery with a variety of mechanisms. Data cen-ters and other key sites can be connected in multiple redundant ways to the MPLS core network. Secondly, remote sites can quickly and easily reconnect to backup locations if needed and applica-tions can be re-routed around any failed links or network connecapplica-tions in real time. An MPLS-based network offers greater high availability, which is critical for an enterprise’s business success.

Enterprise MPLS versus carrier MPLS

Historically, MPLS has been viewed as a WAN and core network technology for service providers and carriers. A whole suite of features with MPLS offers significant benefits to carrier networks as services are offered to the customer base.

Enterprises can also reap the benefits of these features, but because of the less complex nature of enterprise networks, only a subset of features is really applicable. With a simplified MPLS solution based on a subset of carrier-oriented features, enterprises can deploy cost-effective solutions that address enterprise networking needs specifically in each area of their network, from the core to the data center to branch offices or remote sites.

Table 1 illustrates which features are suited to carrier networks and to enterprise networks. Table 1. Enterprise versus carrier MPLS

EnTErPrISE MPLS nETworkS CarrIEr MPLS nETworkS

Limited tenants/business units Many customers

Network enables the business Network is the business (core revenue enabler) Down time directly impacts productivity Down time has liability exposure

No accounting/subscription Accounting/subscription

Limited QoS Hierarchical QoS with thousands of queues Ingress/egress shaping at the provider edge Network bandwidth shaping

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There are some very key differences between enterprise MPLS networks and carrier-class MPLS networks. Many of these differences are outlined in Table 1. One of the key differences is the order of scale of an enterprise network versus a carrier network. Carrier networks can be very extensive, supporting more than thousands of users, services and applications simultaneously. Enterprise networks, on the other hand, are often smaller in scale and built to meet the specific needs of that individual enterprise. Hence enterprises do not have the need for accounting/subscription features or the requirement for multiple, hierarchical layers of QoS.

Operations, Administration and Maintenance (OA&M) features allow network operators to quickly and efficiently troubleshoot networks to isolate and resolve any problems. Enterprises often need only basic OA&M features to check IP connectivity or to find the route of an IP packet in the network. Shaping traffic flows or traffic engineering is another important attribute of an IP/MPLS network. Traffic engineering is typically used by carriers to route services across their network to guarantee service delivery to their customers based on service level agreements (SLAs). Large enterprises may also have requirements that are as stringent as a carrier’s and traffic engineering assists in ensuring application delivery to different business divisions or departments within the large enterprise. How-ever, most enterprises do not require the complexity of MPLS traffic engineering and the associated additional operational overhead within their network infrastructure. The ability to assign priorities to mission-critical data at the provider edge of the network is often sufficient for the majority of enterprises.

Alcatel-Lucent MPLS network architecture

Alcatel-Lucent has a broad portfolio of IP networking products that support MPLS for the enter-prise. Each family of products has characteristics that are suited for specific areas of the network as outlined in this section.

Figure 2. alcatel-Lucent MPLS-enabled architecture

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Benefits of MPLS in the Enterprise Network | Application Note 5 Core network

The core network of an enterprise has more stringent operating requirements than other areas of the network because it is the backbone of the network infrastructure. Typically the core requires a higher level of scalability and availability coupled with the ability to deliver multiple types of services efficiently over the consolidated network.

The Alcatel-Lucent 7750 Service Router (SR) and the Alcatel-Lucent 7450 Ethernet Service Switch (ESS) are carrier-class platforms that deliver advanced services such as VPLS, Virtual Private Wire Services (VPWS), Virtual Private Routed Networks (VPRNs) and IPv6-based services. Both plat-forms support QoS and hierarchical QoS to guarantee service and application delivery across the core, as well as advanced OA&M features to facilitate troubleshooting. The 7750 SR also supports multiservice interworking with support for Frame Relay, ATM and Ethernet pseudowire services. Data center

The key to an effective data center is simplicity of network design so that enterprises can streamline operational processes and maintenance costs. This proves to be challenging because data centers are composed of multiple servers that host a variety of business-critical enterprise applications. Also, a high volume of traffic traverses a data center and so scalability is an important requirement along with high availability. A growing trend in data centers is the need to provide virtualization and partitioning of applications and servers to protect mission-critical data.

Alcatel-Lucent provides end-of-row switching for data centers with the OmniSwitch™ 9000 Chas-sis LAN Switch (CLS) family of products. The OmniSwitch 9000 CLS products deliver scalable LAN switching solutions with integrated security, QoS features and high availability. The Om-niSwitch 9000 products also have extensive support of IP multicast to provide voice, video and data applications.

A recent addition to the product family is the Alcatel-Lucent OmniSwitch 9000E, which provides the suite of features of the OmniSwitch 9000 products coupled with support for MPLS. The Om-niSwitch 9000E is built from the same base and architecture as the OmOm-niSwitch 9000 products with a subset of interchangeable cards to maximize return on investment for enterprise customers. The OmniSwitch 9000E enables the extension of MPLS solutions to the enterprise data center with its support of multiple Virtual Route Forwarding (VRF) and MPLS-based IP VPNs. Edge network

The edge of the enterprise network is where aggregation of multiple users and devices occurs. High speed is required at the edge where more sophisticated applications continue to be utilized by en-terprise users. Enhanced security is also critical at the edge of network to prevent any anomalies or rogue users from entering the network.

The Alcatel-Lucent OmniSwitch 6850 Stackable LAN Switch (SLS) series is a line of fixed configuration switches capable of Layer 3 Gigabit Ethernet and Power over Ethernet (PoE). The OmniSwitch 6850 SLS series excel at the edge where they deliver line-rate Gigabit switching and routing performance along with extensive network security features, enabling corporations to realize the full potential of secured networks. They are advanced, stackable, triple-speed and 10G uplink switches that perform wire-rate Layer 2 switching and Layer 3 routing for both IPv4 and IPv6 na-tively, with optimal QoS for mission-critical applications. The family of products also offers PoE to support IP phones, wireless LAN access points and video cameras.

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End-to-end MPLS-based applications

The Alcatel-Lucent products just mentioned can be deployed in various MPLS solutions that address the networking needs of enterprises. The most common application of MPLS is to create IP VPNs.

IP/MPLS VPNs

VPNs can be used to share resources within an overall IP-based infrastructure while providing the benefits of a private network to different companies or separate divisions within the same company. VPNs provide partitioning of equipment, applications and users and can secure mission-critical data across a shared network (private or public). A shared network reduces costs and operational over-head for the enterprise. A VPN can also be extended to customers and partners, thereby improving communications and optimizing day-to-day business processes.

MPLS introduces the concept of VRF. Routers have the ability to calculate and support multiple route forwarding tables. These tables can be mutually exclusive or they could have some connectivi-ty. Businesses can select which routes should be seen by specific divisions and which cannot be seen. VRF tables are very easy to configure and maintain and represent the simple solution to extending the benefits of VPNs to data centers or branch offices.

Figure 3. End-to-end MPLS VPns OmniSwitch 6850 OmniSwitch 6850 _OmniSwitch 9000E 7750 SR 7750 SR 7750 SR IP/MPLS core 7450 ESS 7450 ESS 7450 ESS OmniSwitch 9000E VPN B VPN C VPN A Enterprise class MPLS Carrier class MPLS OmniAccess 5700 Branch office Corporate office Headquarters Convergence

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Benefits of MPLS in the Enterprise Network | Application Note 7 With MPLS, enterprises also have the ability to converge multiple applications such as voice, video and data over the same IP/MPLS network. The ability of MPLS to apply QoS parameters to high-priority applications ensures that business-critical data has guaranteed delivery over the network. Figure 4. Convergence over an IP/MPLS network

Voice Video

Data IP/MPLS

core

ATM Frame relay/_Ethernet

Conclusion

MPLS is a technology that is extremely beneficial to enterprises. MPLS simplifies the network infrastructure by allowing the consolidation of multiple technologies and applications such as voice, video and data. MPLS provides enhanced security, scalability and high availability.

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APPLICATION NOTE. Benefits of MPLS in the Enterprise Network

Abstract

Table of contents

Introduction

Market trends and customer issues

Conclusion