Ethernet business access Services without boundaries

Transcription

1 T E C H N O L O G Y W H I T E P A P E R business access Services without boundaries The use of -based business services is growing significantly providing higher bandwidth with greater flexibility and transparency at a lower cost than traditional business services. Service providers must deliver high-speed access to business services and provide connectivity to more enterprise sites in more locations without significantly increasing cost or complexity. meets the bandwidth, flexibility, service transparency and low-cost requirements to deliver high-speed access to business services. And business access helps service providers offer enterprise customers new bandwidth-intensive applications and managed services, previously too costly to deploy using traditional access services. The shortage of deployed fiber leads service providers to consider leveraging their existing last-mile copper access networks to deliver access so they can offer costeffective, efficient and reliable carrier-class business services. This whitepaper describes the options and requirements for extending the reach of business services using.

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3 Table of contents 1 1. Executive Summary 1 2. Market 3 3. Defining business access 6 4. Basic Requirements for Business Access 9 5. Emerging requirements in business access Hybrid packet/tdm and TDM on the same copper line Scalability, reliability and resilience for campus and large enterprise sites Interworking with legacy TDM, frame relay and ATM access services Intelligent demarcation devices Conclusion Glossary

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5 1. Executive Summary 2. Market Business services such as carrier Virtual Leased Lines (VLL), Virtual Private LAN Service (VPLS) and IP Virtual Private Networks (VPN) continue to grow significantly, with analysts predicting the market will reach around $31 billion (United States) in 2008 and growing to around $47 billion (United States) in These new business services are increasingly popular with both small-to-medium enterprise (SME) customers and large enterprise customers as they provide higher bandwidth with greater flexibility and transparency at a lower cost than traditional business services such as T1/E1 leased lines and frame relay. Enterprise customers require increased bandwidth, reach, scalability and reliability for voice, data and video traffic, and they are deploying new applications to meet crucial business objectives such as increasing efficiency and reducing costs. Service providers are challenged to deliver higher speed access to business services, provide connectivity to more enterprise sites wherever they are located all without significant increases in cost and complexity. meets the bandwidth, flexibility, service transparency and low-cost requirements to deliver higher speed access to business services. It provides a universal handoff with clear service demarcation and offers much greater service flexibility with easily scalable bandwidth and the ability to deliver multiple services over a single interface. business access helps service providers offer enterprise customers new bandwidth-intensive applications and managed services, previously too costly to deploy using traditional access services. Consolidating Enterprise servers makes server virtualization a possibility, presenting further opportunities for managed and hosted services and applications. But is usually delivered directly over fiber. Although fiber availability has increased dramatically, according to the Vertical Systems Group, the vast majority of enterprise sites in the United States and Europe still have no access to fiber, with small and medium sites disproportionately underserved compared to large enterprise sites. This fiber gap has led to significant growth and interest in leveraging existing investments by delivering over existing last-mile access networks to extend the flexibility, reach and assurance of business services. Service providers are challenged to determine which methods are most appropriate to deliver cost-effective, efficient and reliable carrier-class business services. Service providers need to choose the right access technology and the right product portfolio to deliver consistent end-to-end services, management tools capable of assuring and reporting end-toend service level agreements (SLAs), and industry-standard solutions such as those certified by the Metro Forum (MEF). Without this combination, delivering carrier-class business services is not possible. This whitepaper examines the current market, defines business access, outlines basic requirements, describes available options, and highlights emerging trends in delivering business access. It shows how business access can offer cost effective and flexible ways to deliver business services over last-mile access technologies truly enabling services without boundaries. The carrier services market is growing rapidly. In particular, business VPN services such as point-to-point leased lines using over SONET/SDH (EoS), over MPLS (EoM- PLS), multi-point VPNs using virtual private LAN service (VPLS), and access for high-speed Internet and multi-point IP VPNs are widely deployed. These services are increas- 1 and IP MPLS VPN Services, Infonetics, June 2008 business access Services without boundaries Technology White Paper 1

6 ingly popular with both large enterprise and small-to-medium enterprise (SME) customers with higher bandwidth, greater flexibility and service transparency at a much lower cost than traditional services such as T1/E1 leased lines and frame relay. The demand for carrier services is unprecedented, compelling service providers to expand their business services and deliver them more cost effectively wherever needed. Fiber is the favored technology to deliver carrier business access services. However, while fiber is used extensively for high-capacity transport in service provider backbone networks, it is not widely available in many last-mile access networks where copper continues to dominate. According to Vertical Systems, in 2007, the vast majority of business sites in the United States and Europe had no access to fiber, with small and medium business sites disproportionately underserved compared to large business sites. Where business sites are not fiber-connected, service providers may opt to build fiber out to the building if it is within easy reach of their existing fiber footprint. The decision to deploy fiber is driven by competition, the business value of the service contract or the number of potential businesses within or in the proximity of the same building, campus or business district. The main considerations for the service provider are construction expenses, time to completion and local regulations. Businesses in the same buildings, campus or districts in major metropolitan areas will most likely have access to fiber. In such multi-tenant unit (MTU) sites, multiple service providers often collocate in the largest buildings, providing service choice for multiple businesses at and around these sites. Businesses in smaller buildings and in less populated areas, or remote and branch office sites of national or international enterprises are least likely to have access to fiber and require access over the existing copper infrastructure. This has prompted an increased interest in dedicated platforms to deliver business access over copper, such as over bonded copper and over TDM access circuits. Another emerging trend is the active deployment of new fiber infrastructure for residential triple play applications. This can be deployed by either incumbent operators or by alternative operators as part of municipal open access networks or economic regeneration projects to address the digital divide. This fiber deployment in predominantly residential areas increases service accessibility to adjacent business sites. This in turn leads to the requirement for converged access platforms that support both residential and business customers and can meet different requirements on a single platform. The importance of business access has driven the emergence and rapid growth of a new class of optimized product that provide access to a wide range of residential and business services. Heavy Reading calls this product a Carrier Access Platform (CEAP) 2. Heavy Reading defines the CEAP market in several sub-segments: over PDH/TDM access circuit platforms over bonded copper pair platforms over fiber switch/intelligent demarcation platforms Although starting from a relatively small base, and taking into account the recent economic downturn, Heavy Reading estimates the global market for specialist CEAP equipment grew 15 percent in 2008 to reach $390 million (United States) and will reach over $600 million (United States) by Most of this growth is likely to be fueled by success-based carrier business service deployments and we can t wait for fiber infrastructure builds. 2 Carrier Access Platform Quarterly Market Tracker, Heavy Reading, January business access Services without boundaries Technology White Paper

7 3. Defining business access Service providers are gradually changing the way they deliver business access services. Business access was originally dominated by TDM and ATM-based offerings, but lack of bandwidth flexibility, poor granularity and high WAN interface costs have led service providers to migrate toward -based business access offerings. The main drivers are increasing customer demand, lower cost, greater flexibility and increased bandwidth granularity of. This enables service providers to move from a stove-pipe legacy infrastructure to a next-generation converged infrastructure that is based on IP and to simplify network management and reduce operational (OPEX) and capital expenditures (CAPEX). With the new carrier-grade IP/ infrastructure, service providers can offer a wider range of business services including: Data services Internet access (secure/corporate) Private networks VPN access (network based) Layer 2 VPN point-to-point virtual leased lines, point-to-multipoint transparent LAN services, multi-point virtual private LAN service (VPLS) Layer 3 VPN any-to-any multi-point IP VPN services Voice services IP PBX connection (VoIP) Legacy PBX connection T1/E1 and ISDN2/ISDN30 Emulation of legacy services E1/T1 leased lines Frame relay and ATM The emerging carrier access platforms (CEAP) and associated customer premises equipment (CPE), or customer located equipment (CLE), that support these services must be optimized to provide business access efficiently and cost effectively over existing and new access infrastructures. These include: over DSL uses over ADSL(2+), VDSL2, and G.SHDSL to extend business services to small offices, home offices and small business sites at low-band data rates of typically between 2 Mb/s and 20 Mb/s, depending on technology and distance. over PDH/TDM uses over bonded circuits so service providers can leverage their large installed base of T1/E1 and T3/E3 access circuits to provide mid-band access to existing customer sites, large and small. Bonding provides bandwidth flexibility and ensures service resilience if a link fails. over PDH uses standard encapsulation technologies such as PPP, HDLC, G and standard circuit bonding such as MLPPP, PDH VCAT, G and LAG. over PDH/TDM delivers mid-band data rates of typically between 2 Mb/s and 30 Mb/s, depending on the technology. over bonded copper, also known as in the First Mile over Copper (EFMC) uses over G.SHDSL to provide access over bonded twisted copper pairs at midband data rates of typically between 20 Mb/s and 50 Mb/s. depending on distance. Although most business sites lack fiber access, almost all businesses have enough copper pairs available to deliver over bonded copper. For service providers, EFMC offers rapid deployment to most enterprise sites at minimal CAPEX and with a fast return. business access Services without boundaries Technology White Paper 3

8 over Data over Cable Service Interface Specification (DOCSIS) although used mainly for residential triple play services, DOCSIS allows cable operators to use existing hybrid fiber coax (HFC) plant to deliver business services to SME customers. DOCSIS allows cable operators to use existing copper coax for low-band access rates of up to 10 Mb/s, while fiber can be used to provide mid-band access rates of typically between 10 Mb/s and 100 Mb/s, depending on the version of DOCSIS used. DOCSIS allows integration of both coax and fiber access into a single network. over PON (EPON or GPON) an IEEE 802.3/EFM standard for using over a point-to-multipoint passive optical network (PON). PON is a fiber-to-the-premises network architecture that uses unpowered optical splitters to enable a single optical fiber to serve multiple premises, typically 32 to 128. PON uses wavelength division multiplexing (WDM), with one wavelength for downstream traffic and another for upstream traffic on a single fiber. EPON supports symmetric data rates of up to 1 Gb/s upstream and downstream shared between the multiple premises served and uses native IEEE quality of service (QoS), protection and resilience mechanisms. An IEEE Task Force is also working on 10GigEPON that is backward compatible with EPON. over SONET/SDH uses existing service provider SONET/SDH access networks for highly resilient and protected access to business services. over SONET/SDH presents interfaces toward the customer and SONET/SDH interfaces toward the network. Using this approach, most of the SONET/SDH network remains unchanged. Only the CPEs need to be -aware. Service providers can deploy business access easily on existing Multi-Service Provisioning Platforms (MSPPs) by adding an over SONET/SDH line card. over SONET/SDH uses standard encapsulation technologies such as X.86 and GFP and standard circuit bonding such as VCAT and LAG. over SONET/SDH supports sub-rate and bonding VCAT. Fixed data rates between 10 Mb/s and 1 Gb/s are typical. over point-to-point fiber enables deployment of native IEEE directly over fiber to deliver very scalable bandwidth at data rates from 100 Mb/s up to 10 Gb/s. This approach offers granular control of bandwidth and uses native quality of service (QoS), protection with redundant links and resilient rings, OAM performance monitoring and fault notification, secure service demarcation and management, and 802.3ah OAM management and provisioning. over MPLS/VPLS provides a solution for large sites, campuses or multi-tenant buildings. Service providers can deliver highly scalable, reliable, resilient and traffic-engineered access to business services for multiple enterprises, typically with multiple 10/100 Mb/s fiber or copper customer-facing ports and multiple fiber network facing ports at data rates of up to 1 Gb/s. over WDM enables multiple wavelengths per fiber link, with each wavelength supporting a different data stream. CWDM is typically used for over WDM access with support for up to 18 wavelengths per fiber. Add/drop multiplexers provide new access points by splicing into the WDM fiber. WDM is cost effective as it increases fiber access capacity and minimizes installation of new fiber. It also uses small form factor pluggable transceivers, multiplexers and media converters that enable WDM wavelengths with existing infrastructure equipment. WDM is scalable so service providers can add new fiber access quickly with standard hardware. Separate wavelengths can also be used to deliver a mix of different network protocols, such as and TDM services over one fiber link. In addition, CEAP and associated CPE must offer converged solutions optimized for both residential and business customers and served from a single platform, and dedicated solutions optimized for one type of customer served from a single platform. They must provide transparent access to services, offer a range of LAN and legacy interfaces options, provide bandwidth management, support VLANs and multiple levels of QoS for latency-sensitive data, and provide protection, restoration, redundancy, and end-to-end service management. 4 business access Services without boundaries Technology White Paper

9 Figure 1. Defining Business Access Converged platform Residential and business customers served from a single platform Dedicated platform One type of customer served from a single platform Customer Service provider Telephone ISDN Telephone IP Legacy PBX Legacy services IP PBX Switch PWE3 gateway Customer LAN Userto-Network Interface (UNI) Customer premises equipment (CPE) demarcation Networkto-Network Interface (NNI) Carrier access platform (CEAP) Metro IP/MPLS business access Implies transparency, bandwidth management, QoS and traffic engineering, protection, restoration, redundancy, OAM end-to-end service management, MEF certification As service providers move to a converged infrastructure for business and residential services, endto-end service provisioning, monitoring and assurance is essential. Fortunately, operations, administration and maintenance (OAM) standards, such as IEEE 802.3ah Link OAM, 802.1ag Connectivity Fault Management, and Y.1731 Performance Monitoring, are now widely implemented and available. As a result, service providers can select products to address the business access market particularly those markets with existing copper infrastructure, where service providers want to maximize their investment in existing assets. In addition, the MEF certification program is becoming the benchmark for carrier access products deployed in service provider access networks. Support for carrier-class business access services is not possible today without the right products which provide the right features to comply with the latest industry specifications and standards, as shown in Figure 1. Some business access requirements are described in more detail in section 4. In addition, service providers must select products suitable for the different segments of the business access markets. These segments are small office home office (SOHO), small-to-medium enterprises (SMEs) and large enterprises. Not surprisingly, each segment has its own particular service requirements, including bandwidth, availability and service level reporting. Table 1 details these requirements categorizing them as low, medium or high priority. Table 1. Business Category and Typical Characteristics and Requirement Priority Typical Characteristics and Requirement Priority Business Category Number of employees Connection speed Fiber availability Availability and scalability Remotely managed SLA Reporting Legacy PBX and services VoIP and IP PBX Small Office/ Home Office Small-to- Medium (SMB) Medium-to- Large 1 to 4 2 Mb/s 10 Mb/s 5 to Mb/s 50 Mb/s 250 to Mb/s 100 Mb/s Low Low Medium Low Low Low Low - Medium Medium Medium Medium Medium Low -Medium Medium - High High High High Medium - High Medium Large 500 to Mb/s 1 Gb/s High High High High High Medium Campus and MTU More than Gb/s 10 Gb/s Very High Very High Very High Very High Very High High business access Services without boundaries Technology White Paper 5

10 The SOHO category includes small branch offices but also employees of larger businesses who telecommute and self-employed people who work at home for their own businesses. A typical SOHO site has fewer than four people working in it, and connection speeds do not usually exceed 10 Mb/s and fall into the low-band range. Upstream and downstream connection speed requirements may differ, making DSL, cable and PON ideal technologies for SOHO sites. Although service availability and scalability requirements and SLA reporting requirements are usually low, SOHO sites often require a remote management capability. Typically, there is no PABX on site, but requirements for VoIP are increasing. IPTV connectivity is also often present in a home office environment. The SME segment is also known as the small to-medium business (SMB) category, although the definition of the number of employees varies. Some analysts define small businesses as having 5 to 99 employees, while medium-sized businesses are defined as having 100 to 249 employees. Compared to the SOHO category, typical service availability and scalability, remote management and SLA reporting requirements are higher. There is usually some form of PABX present and VoIP and IPTV requirements are increasing. Connections speeds fall in the mid-band range of between 10 Mb/s and 50 Mb/s, and typically upstream and downstream connection speeds are similar. Due to the large number of SME sites already using TDM and the relatively scarce availability of fiber, over TDM and over bonded copper technologies are particularly appropriate for SME sites. Where fiber is available, over SONET/SDH and over point-to-point fiber are also important. Medium-to-large enterprise sites are typically defined as having between 250 and 500 employees, while large enterprise sites have typically up to 1000 employees. These business categories have stringent requirements on service availability and scalability, remote management and service level reporting. Typically a large PABX is present and many sites have multiple connections to existing legacy TDM, frame relay and ATM services. Both categories typically require multiple connections for redundancy with speeds that fall in the high-band range of 50 Mb/s and higher. Many sites in these categories are within existing business areas so many such sites fall within the fiber footprint. In these categories, multiple connections at speeds of 100 Mb/s are common and it is not unusual for multiple connections at speeds up to 1 Gb/s. In such cases, technologies such as over point-to-point fiber and over MPLS/VPLS are most appropriate. Campus and MTU sites typically have more than 1000 employees, and as multiple business units or enterprises may share the same fiber-connected site or building, they have the highest requirements on service availability and scalability, remote management and service level reporting. They often have additional requirements such as multiple connections for redundancy, traffic load balancing, and security. Typically, many enterprises in these sites have PABX and some also have multiple connections to existing legacy TDM, frame relay and ATM services. Redundant connections at speeds higher than 1 Gb/s are typical with some sites requiring connections at speeds up to 10 Gb/s. Technologies such as over point-to-point fiber and over MPLS/VPLS are most appropriate for campus and MTU sites. over WDM is appropriate for sites requiring very high speed connections. 4. Basic Requirements for Business Access Section 2 outlined: The emergence and rapid growth of carrier access platforms (CEAP), a new class of product that provides access to a wide range of business and residential services The distinction between converged platforms optimized for both residential and business customers served from a single platform, and dedicated platforms optimized for one type of customer served from a single platform The basic requirements for carrier business access platforms and customer premises equipment (CPE) are outlined in the following paragraphs. 6 business access Services without boundaries Technology White Paper

11 Cost-efficient hardware with redundant features such as power supplies, fans, controller cards, and switch fabrics are mandatory for both CEAP and high-end CPE and campus/mtu devices. For CEAP and some CPE, particularly MTU and demarcation devices, NEBS Level 3 and ETSI certification, such as no fans or moving parts, and three-way redundant power supplies are required to meet additional carrier-grade needs. A variety of mounting options, including rack-mount, shelf mount and standalone, enable easy installation at the customer premises. Increasingly, software redundancy and failure recovery mechanisms are also required to minimize service disruption and ensure SLAs are maintained. Support for both mesh and ring topologies gives service providers flexibility to maximize the use of their fiber plant. Dual uplinks are required to recover from link failures. Dual homing or multi-homing is often vital, and is usually necessary from the MTU device to the aggregation network to enable recovery from a node or link failure. Bandwidth management such as Committed Information Rate (CIR)/Peak Information Rate (PIR) allows the service provider to offer services where certain bandwidths are guaranteed (CIR) in combination with the ability to burst to a higher bandwidth if it is available (such as to the PIR). This feature requires packet processing similar to that used in frame relay to police bandwidth where the peak rate needs to be enforced separately from the committed rate. IEEE standards and related IEEE standards, including 802.1Q VLAN tagging, 802.1p prioritization, 802.1s Multiple Spanning Tree Protocol, 802.1w Rapid Spanning Tree Protocol (RSTP) and others are basic requirements for CEAP. IEEE 802.1ad, also known as provider bridges, Q-in-Q, or stacked VLANs, expands the VLAN space by tagging the customer VLANs using service VLANs or S-VLANs, thus producing a double-tagged frame that can be forwarded (or tunneled) transparently across the service provider network. The provider bridge looks like a simple bridge port to the customer s traffic and maintains the customer s VLANs. The expanded VLAN space allows providers to offer services on specific VLANs for specific customers while allowing them to offer other services to their other customers on other VLANs. Broadcast limiting is needed as broadcasts initiated from an end customer can severely clog the network. Hence, service providers want to set an upper limit on the bandwidth available for broadcast packets. This is relatively simple on a CPE, involving a simple classification per port with subsequent limiting. On a CEAP access switch, this usually involves hierarchical QoS mechanisms (H-QoS), since it implies classification and queuing within a certain S-VLAN, which itself needs classification and queuing. Transparency is required when tunneling customer BPDUs/VLANs, including native protocols and layer 2 control protocols across the service provider network. This ensures customer protocols do not disturb or interfere with any other protocol that may be running on the service provider s network. A physical port can be mapped to a VLAN ID on the CPE, associating that port with a service, for example Internet access or VPN. It is similar on the CEAP, except that a port is associated with a customer. There are two models when considering VLAN mapping on both the CPE and CEAP: The CPE customer VLANs are mapped to a service based on the physical port of the CPE. On the CEAP, these VLANs are mapped into an S-VLAN associated with the customer. Both customer VLANs and service VLANs are added to the CPE. Dual tagged S-VLANs arrive at the CEAP. As IEEE 802.1ad does not offer true separation of customer and provider domains and forwarding is still based on the customer destination MAC addresses, other mechanisms may be needed to help with MAC scaling, particularly for campus/mtu and large enterprise sites. business access Services without boundaries Technology White Paper 7

12 Figure 2 End-to-end service OAM standards Customer premises Service provider domain Customer premises UNI NNI NNI UNI Customer network CPE CEAP Metro CEAP CPE Customer network 802.3ah link OAM 802.1ag connectivity fault management Y.1731 performance management OAM tools that provide end-to-end service assurance, and measure and report SLAs are essential for business access solutions. Standards-based OAM such as IEEE 802.3ah Link OAM, 802.1ag Connectivity Fault Management, and ITU-T Y.1731 Performance Monitoring, as shown in Figure 2, fulfill these requirements to a large extent. IEEE 802.3ah provides a physical link layer OAM, for monitoring and troubleshooting a point-to-point full-duplex link. It is particularly valuable in the last-mile connection to the network demarcation or CPE device where most link failures typically occur. IEEE 802.1ag Connectivity Fault Management provides end-to-end network OAM and service management (where a service is identified by a VLAN or MPLS pseudowire). Features of 802.1ag include discovery and auto-negotiation of OAM capabilities, link performance monitoring, remote fault indication and remote loopbacks ag also provides capabilities for connectivity verification, and detection and isolation of connectivity failures. Y.1731 is complementary to and a superset of 802.1ag. The ITU-T developed Y.1731 in cooperation with the IEEE, defining further end-to-end VLAN-based service transport OAM functionality. Several additional features offer performance monitoring capabilities that work at the service layer rather than the physical layer. Service providers are experiencing an overwhelming demand for robust business access devices due to the rapid growth of carrier business services. This leads to an increasing need for very scalable, reliable, cost-effective and easy-to-use OAM tools that provide end-to-end provisioning, assurance and troubleshooting. End-to-end in this context includes the CPE, the CEAP and carrier switch router and service router devices in the aggregation and core networks. These tools need to offer an integrated approach to element, network and service management. In the business access segment, more specifically for the SME and large enterprises, management of CPE today is typically based on SNMP and CLI through an element manager rather than TR-069, which is more common in residential applications. This implies that matching of management features for CPE and CEAP and their respective element managers must be considered. In addition, these element management tools must integrate with higher level network and service management platforms and existing OSS/BSS systems to provide integrated end-to-end capabilities. 8 business access Services without boundaries Technology White Paper

13 The MEF is a global industry alliance with approximately 120 member organizations, including service providers, equipment vendors, test vendors, testing organizations, software manufacturers, and semiconductor vendors. The MEF develops technical specifications, implementation agreements and certification programs to promote interoperability and deployment of carrier services worldwide. Specification test procedures and certification programs are an increasingly important activity of the MEF Technical Committee. The following abstract test suite specifications have been developed and published by the MEF Technical Committee: MEF 9 defines the requirements and corresponding test procedures that determine the readiness of Metro Network (MEN) and Metro equipment to deliver various services, such as Line (E-Line) and LAN (E-LAN) services. MEF 14 defines the requirements and corresponding test procedures for service performance and bandwidth profile service attributes that may be specified as part of a Service Level Specification (SLS) for an service. MEF 18 defines the requirements and corresponding test procedures for Circuit Emulation Services over. MEF 19 defines the requirements and corresponding test procedures for the User-to-Network Interface (UNI) Type 1 (manual configuration) defined in MEF 13. MEF 21 is the first part of a set of requirements and corresponding test procedures for the Userto-Network Interface (UNI) Type 2. MEF 21 defines the link OAM requirements and corresponding test procedures for UNI Type 2. Further test suites are being defined by the MEF and will be published in the future. MEF certification is becoming a standard requirement both for products from equipment vendors and services offered by service providers. Certification assures service providers that equipment supplied by vendors can deliver MEF compliant services, and assures customers that services they buy from service providers are compliant with MEF specifications. 5. Emerging requirements in business access The continued growth of business services means a corresponding increase in the number of enterprises, sites and services delivered. Typically, enterprises start to use and become familiar with business services at a few sites. Once they are comfortable that business services can meet their requirements, they want to migrate all of their sites. This places additional strain on service providers as they scale and extend the reach of their business services cost effectively and reliably to meet the increased demand. In many cases, this means leveraging both their existing copper and their fiber infrastructure to reach more enterprise sites. In addition, many enterprise customers are using traditional services and have legacy environments and equipment they need to support while migrating to new solutions. Finally, as the number of customers, sites and services delivered increases, service providers need more sophisticated CPE to deliver endto-end business services reliably and cost effectively and meet more stringent SLAs. The following sections provide information about emerging requirements in business access that help address the above issues. These requirements aim to make business access more ubiquitous, scalable, reliable and resilient to provide both the bandwidth and services required by enterprise customers. 5.1 Hybrid packet/tdm and TDM on the same copper line Service providers are challenged to provide business access to the vast majority of enterprise sites that do not have access to fiber. Another challenge is that many business sites are currently connected by copper T1/E1 lines. T1/E1 bonding has frequently been used to increase bandwidth, but bonding more than six to eight T1/E1 copper lines is complex and costly. business access Services without boundaries Technology White Paper 9

14 The answer to these challenges is a technology that simultaneously provides business access services and TDM on the existing copper infrastructure. Using IEEE 802.3ah -in-the- First-Mile over Copper (EFMC), service providers can offer high bandwidth business access to enterprise customers by significantly increasing the bandwidth capacity over existing copper infrastructure. In fact, with this technology, service providers can accelerate business access deployment to copper-connected sites with speeds typical of many fiber-connected sites. By also adding a unique technology that transports TDM simultaneously with over the same copper line, the service provider can also enable a smooth migration from TDM access to all-packet access. IEEE 802.3ah EFM covers a number of areas that address the deployment of in copper and fiber access networks, including two new physical layers for over copper that address two very different and important market segments. The first technology, 2BASE-TL, is a long-reach over copper technology, which focuses on high-bandwidth symmetric services for business customers. 2BASE-TL is the natural upgrade and replacement for T1/E1 and is based on G.SHDSL. The second technology, 10PASS-TS, is a short-reach, high-bandwidth asymmetric technology for in-building or fiber-to-the-curb (FTTC) deployments. The 10PASS-TS technology permits more bandwidth options and is based on VDSL. Both 2BASE-TL and 10PASS-TS enable service providers to deploy business access across voice-grade copper pairs in existing access networks. The EFM technologies cover the full spectra of copper access deployment possibilities from shortreach to long, from residential access to business access. 10PASS-TS offers very high data rates on very short loops, reaching as high as 100 Mb/s in asymmetric mode, and 50 Mb/s in a symmetric mode. The technology is targeted at loops up to 1500 meters (5000 feet) and is primarily aimed at asymmetric, very high bandwidth residential triple play services. 2BASE-TL delivers symmetric services to business customers from service provider central offices and remote terminals. It supports loops covering distances of 2700 to 3600 meters (9000 to 10,000 feet) and beyond. 2BASE-TL delivers high bandwidth services at a maximum symmetric rate of 5.7 Mb/s per copper pair. New chipsets are also making it possible to reach up to 15 Mb/s per copper pair. By bonding multiple copper pairs, mid-band data rates of between 10 Mb/s and 50 Mb/s are easily achievable. In addition, 802.3ah loop aggregation techniques are able to optimize the utilization of copper pairs as well as add and remove pairs to and from the aggregate to increase resilience and redundancy. Copper pairs can come and go, and the interface remains operational only the available bandwidth is affected. New pairs can be wired up and automatically joined to the aggregate group with no additional configuration, realizing the plug-and-play potential of. The resiliency of 802.3ah loop aggregation can satisfy the most demanding business customers and support any application. When a pair fails, that pair is detected and removed from the aggregate in just a few milliseconds. Established connections remain operational, and applications and their users are unable to detect that one of the pairs has failed, except by the loss of some bandwidth. When that pair comes back online, it is seamlessly added to the aggregate. This again is completely transparent to the applications and their users. As well as requiring higher bandwidth business access, many enterprise sites also need to support legacy T1/E1-connected devices, such as PBX, which are sensitive to latency, jitter, bit errors and timing. Even when upgraded to over bonded copper (with considerably more bandwidth than T1/E1s), data rates are much lower than fiber in the 10 Mb/s to 50 Mb/s range. That means latency, jitter, bit errors and timing can become issues when trying to handle legacy TDM by encapsulating in over last-mile copper facilities. However, hybrid packet/tdm solutions offer a high quality, highly resilient solution that eliminates jitter and bit error multiplication, thus ensuring a synchronization signal that meets E1 and T1 standards. The hybrid packet/tdm solution does this by handling EFM and TDM traffic natively 10 business access Services without boundaries Technology White Paper

15 retaining all of the requisite native TDM attributes and physical layer timing delivered by E1/ T1s. With E1/T1s, loss of a single pair will result in loss of service and synchronization. By contrast, the hybrid packet/tdm solution using a single transport facility that carries native TDM traffic as well as native spreads and prioritizes TDM timeslots across the bonded copper pairs, while dynamically allocating the remaining bandwidth for the traffic. With the hybrid packet/tdm solution, the service provider reaps all the benefits of TDM synchronization, unlike the case with circuit emulation over a copper-based packet link. There is not the problem of stranding bandwidth through static allocation of traffic streams over specific copper pairs as with TDM backhaul links over dual-bearer mode technologies. The technology delivers any mix of native TDM and native over bonded copper and is an alternative to pseudowire transport over the copper access networks. It overcomes the limitations of pseudowire on copper access networks by: Partitioning a bonded copper connection into bits that carry TDM traffic and bits that carry traffic, and Transporting TDM natively rather than bundled in a packet format. The hybrid packet/tdm solution also has the advantage that it can be used by mobile operators moving to 3G and eventually 4G cellular networks. Many of these operators are offloading their broadband data onto high-bandwidth backhaul networks while leaving E1/T1s in place in the interim (for voice services and timing). The hybrid packet/tdm solution allows them to benefit from the bandwidth performance and cost advantages of without jeopardizing the benefits and performance of E1/T1s for voice and physical layer timing, as shown in Figure 3. Figure 3 Native and native TDM over bonded copper Native TDM + Native + Cell site Enterprise site Hybrid packet/ TDM platform Hybrid packet/ TDM platform service switch Service router Bonded copper Alcatel-Lucent 1532 Copper Line Access Switch The Alcatel-Lucent 1532 Copper Line Access Switch (CLAS) is an innovative hybrid packet/tdm platform that simultaneously delivers native traffic with native TDM traffic over the same bonded copper connections. Using IEEE 802.3ah -in-the-first-mile over Copper (EFMC), it delivers symmetrical point-to-multipoint business access services at data rates of up to 45 Mb/s over existing copper pairs utilizing standards-based 2BASE-TL technology. The Alcatel-Lucent 1532 CLAS supports end-to-end OAM and is MEF-compliant for services. By partitioning the bonded copper connection into bits that carry traffic and bits that carry TDM traffic, the solution also handles time-critical TDM traffic over copper access networks. As TDM is carried natively and not in packet format, the solution resolves synchronization issues and reduces jitter and the bit error rates for time-critical data. The Alcatel-Lucent 1522 Copper Line IP (CLIP) complements the Alcatel-Lucent 1532 CLAS and provides a low-cost, hybrid packet/tdm device that can be deployed either as customer-premises equipment or as central office equipment. As a CPE, the 1522 CLIP acts as an intelligent demarcation device, supporting line-rate limiting, VLANs, stacked VLANs (Q-in-Q) and CoS and maintaining full interoperability with existing switches, routers and ADM interfaces. business access Services without boundaries Technology White Paper 11

16 Both the 1532 CLAS and the 1522 CLIP support end-to-end OAM and are supported by the Alcatel-Lucent 5620 Service Aware Manager for the fast provisioning and assurance of MEF 9 and MEF 14 certified Carrier services. 5.2 Scalability, reliability and resilience for campus and large enterprise sites As service providers extend the reach of their business VPN services in metropolitan areas, they are often faced with a very aggressive business case. A key component of this business case is the cost of the CPE. In its November 2008 assessment, Synergy Group affirms that one of the most difficult issues for service providers is the cost of customer acquisition. In addition, a growing dependence on business VPN services to support business-critical applications indicates that enterprises are demanding very stringent end-to-end service level agreements (SLAs). Service providers need to cost effectively extend the reliability and manageability of business VPN services right to the customer edge. This requirement is giving rise to the need for next-generation, high performance, small-footprint, business access MTU devices, particularly for campus and large sites serving multiple enterprises or enterprise business units. These MTU devices need to deliver cost-effective and highly scalable and reliable business VPN services while offering stringent SLAs. They need to support innovative and differentiated services, including LAN (E-LAN) and virtual private LAN services (VPLS), point-to-point services such as line (E-line) and virtual leasedline services (VLL) as well as access to Internet enhanced services (IES) and IP-VPN into the customer premises. In addition, many large enterprises have requirements for LAN extension, storage area network (SAN) extension and data-center connectivity, all of which have stringent service requirements. At the same time, these MTU devices must offer fast service provisioning, ease of management and end-to-end service assurance. Figure 4 Scalability, reliability and resilience for MTU, campus and large enterprise sites access devices (EADs) End-to-end service provisioning, management and assurance access devices (EADs) Dual-homed connection MPLS-enabled aggregation networks service switch MIU device MIU device Mesh topology IP/MPLS backbone MIU device access devices (EADs) service switch Service router MPLS extended to customer premises MIU device Ring topology MIU device Robust scalability is a particular requirement for the aggregation networks serving large MTU sites with multiple large enterprises. Mechanisms such as IEEE 802.1ad offer some scalability but it is limited to 4096 VLANs in the service provider backbone network. Also, it does not offer true separation of customer and service provider domains and forwarding is still based on the customer destination MAC addresses. Therefore other mechanisms are needed to help with MAC scaling. One 12 business access Services without boundaries Technology White Paper

17 such mechanism is IEEE 802.1ah-2008, also known as provider backbone bridges (PBB) or MAC-in- MAC. IEEE 802.1ah PBB introduces the concept of backbone bridging specifically to solve address scalability. PBB defines an encapsulation method to hide the customer MAC addresses from the service provider s network. In the backbone bridging domain, all the classic bridging characteristics of the Q-in-Q network apply, except that the PBB edge function hides customer MAC addresses from the backbone by adding a smaller set of backbone MACs. This function allows bridging to occur in the backbone without an explosion of MAC addresses. However, it also means that STP is still required. PBB on its own does nothing to address the scalability concerns, nor provide any increase in the number of VLANs - the backbone network is still constrained to 4096 VLANs. In the past few years, service providers have deployed MPLS at the service edge to deliver business VPN services as well as residential triple play services. MPLS is one of the fastest growing and is becoming one of the most widely deployed technologies across metropolitan area networks. The main reasons are that MPLS allows multiple services to be deployed over a single, robust, scalable, traffic-engineered and manageable infrastructure. MPLS is increasingly becoming a requirement in access networks, particularly for MTUs, to address the poor scalability and lack of separation of customer and provider domains with VLAN schemes such as 802.1ad provider bridges and the requirement to use STP with 802.1ah PBB. The rapid growth of business services has severely exacerbated these scalability issues such that many service providers increasingly see PBB as a mandatory requirement. The integration of PBB with MPLS/VPLS allows optimum scalability to be achieved in the access and aggregation domain. Contrary to how they are often positioned, PBB and MPLS actually complement each other because they each address different scalability dimensions, with PBB addressing the MAC scaling issues and MPLS addressing and the removal of STP, and both ensuring a complete separation of customer and provider domains. This integrated approach therefore allows operators to scale both addressing and connectivity, and the combination of PBB and MPLS is highly effective for service providers that already have a native service deployed but want to extend or scale the service using VPLS or VLL. In addition, MPLS enables dynamic, constraint-based, path selection for LSPs, which provide more control and better troubleshooting in campus/mtu and large enterprise site environments. It has advanced protection mechanisms, such as fast reroute and backup paths, dual homing and multi-homing, and multi-chassis link aggregation for redundancy and load balancing. Also, MPLS provides a scalable and secure tunneling mechanism to provide BPDU/VLAN transparency, and is increasingly used to transport legacy protocols such as TDM, frame relay and ATM using end-toend pseudowires. Service providers need to deliver profitable services to multiple enterprises on campus sites and in large buildings using a single high performance, scalable and reliable MTU device that is capable of delivering multiple differentiated services over a single connection with guaranteed SLAs. These devices need to minimize OPEX by integrating with unified management platforms to manage, measure and monitor end-to-end services efficiently, helping service providers increase revenue with a full suite of highly available, highly scalable carrier business services delivered right to the customer edge The Alcatel-Lucent 7210 Service Access Switch (SAS) The Alcatel-Lucent 7210 Service Access Switch (SAS) is a next-generation, low cost, small footprint, customer edge device designed to extend the reach of metro and MPLS-based business services cost effectively to the customer edge. Offering up to /1000 Gigabit SFP optical ports and supporting 10/100/1000Base-T SFP copper ports for added configuration flexibility, the 7210 SAS is ideal for extending service reach to MTU, campus and large enterprise sites. With support for dual homed point-to-point and ring topologies, the 7210 SAS is a flexible platform that delivers multiple services per port and provides differentiated services by extending SLAs right to business access Services without boundaries Technology White Paper 13

18 the customer edge. The 7210 SAS supports highly scalable, highly reliable and fully managed MEFcompliant E-LINE and E-LAN services as well as high-speed access to enhanced Internet and IP-VPN business services. Using the Alcatel-Lucent 7210 SAS optimizes the business case for extending the reach of carrier and MPLS-based business services to MTU, campus and large enterprise sites. The Alcatel-Lucent 7210 SAS is available as a cost-optimized aggregation device that complements the Alcatel-Lucent service switch portfolio to extend the reach of carrier services, and as a functionally rich MPLS device that complements the Alcatel-Lucent service router portfolio to offer seamless access to application-aware business VPN services. The Alcatel-Lucent 7210 SAS supports end-to-end OAM and is fully supported by the Alcatel-Lucent 5620 Service Aware Manager. This allows fast provisioning, management and assurance of end-to-end MEF 9 and MEF 14 certified carrier services, and simplifies troubleshooting of carrier services. 5.3 Interworking with legacy TDM, frame relay and ATM access services Interworking with and offering TDM, frame relay and ATM access to business VPN services is an approach that has been particularly effective for Layer 3 IP VPNs. The ability to use these legacy access services was instrumental to expand IP VPN service footprints to include locations where fiber access was not available or cost effective. Legacy services can also be used to access business VPN services such as Layer 3 IP-VPNs and Layer 2 VPNs and VPLS. Increasingly, service providers are looking to reduce costs by capping investments in legacy infrastructure and transporting legacy access services such as TDM leased lines and frame relay/atm connections over an IP/MPLS network using pseudowires or virtual leased lines (VLL). Pseudowires emulate native layer 2 services such as an ATM VC/VP, frame relay VC, T1/E1 circuit, SONET/ SDH or. Many pseudowires can be carried across an MPLS network in a single tunnel LSP, and MPLS features can be used for resiliency, QoS, and so on. Pseudowires are configured statically or dynamically established using T-LDP. Figure 5 business access and interworking with legacy services End-to-end service provisioning and assurance PBX N x T1/E1 TDM MPLS-enabled aggregation network TDM/PSTN Router TDM access Service aggregation router IP/MPLS IP VPN CPE PBX FR/ATM Service aggregation router service switch Service router VPLS Router Frame relay/atm access TDM private line service T1/E1 access to IP-VPN service access to VPLS FR/ATM private line services FR/ATM 14 business access Services without boundaries Technology White Paper

19 In the case of TDM, circuit emulation service (CES) capabilities are required over an IP/MPLS network. There are two principal types of circuit emulation: Circuit Emulation Service over Packet Switched Network (CESoPSN) and Structured Agnostic TDM over Packet (SAToP). CESoPSN allows NxDS0 service including full T1/E1 capability, while SAToP provides the ability to carry unstructured T1/E1 circuits across the IP/MPLS network. An MPLS tunnel is used as the transport layer and a pseudowire is created to identify the specific TDM circuit within the MPLS tunnel. Circuit emulation ensures that information required by the T1/E1 circuit is maintained across the packet network to provide a transparent service to the end user. Using existing legacy access services to complement business access services allows service providers to maximize the reach of their business VPN services, generating additional revenue while reducing capital expenditures (CAPEX) and operating expenditures (OPEX). It enables them to use the broadest range of traditional and emerging technologies to provide access to their business VPN services. It also minimizes the need to roll out a new network for each new service and it reduces the number of network nodes that must be deployed and operated, and improves the time-to-market for new services The Alcatel-Lucent 7705 Service Aggregation Router (SAR) The Alcatel-Lucent 7705 Service Aggregation Router delivers industry-leading IP/MPLS and pseudowire capabilities in a compact platform with the ability to groom and aggregate multiple media, service and transport protocols onto an IP/MPLS network. The 7705 SAR provides a powerful and economic solution to help service providers support legacy TDM business access services as enterprise customers migrate to business access services. Sharing much of the market-leading features of the 7750 Service Router (SR) product, the 7705 SAR offers a powerful, service-oriented capability in a compact form factor and price point that are particularly attractive when interworking with TDM legacy services in an business access environment. The 7705 SAR supports Circuit Emulation Service over Packet (CESoPSN) to allow NxDS0 services including full T1/E1 capability and Structured Agnostic TDM over Packet (SAToP) to carry unstructured T1/E1 circuits across the IP/MPLS network. The 7705 SAR uses an MPLS tunnel across the IP/MPLS network as the transport layer and creates a pseudowire (PWE3) for each specific TDM circuit within the MPLS tunnel. All information required by the TDM circuit is maintained across the IP/MPLS network, providing a transparent service to the end user customer. In addition, the 7705 SAR supports Encapsulation Methods for Transport of ATM over MPLS Networks, including inverse multiplexing for ATM (IMA) in which multiple ATM access ports are bundled together to attain higher speeds. The IMA protocol is terminated on the Alcatel-Lucent 7705 SAR and only the cells containing user data that belong to a virtual circuit/virtual path (VC/ VP) structure are transported. Encapsulation Methods for Transport of over MPLS Networks is also supported. To offer greater scalability, all traffic from an port can be carried over a single pseudowire or, alternatively, a pseudowire can be created for each VLAN that is assigned to a different service or end customer. The 7705 SAR provides comprehensive QoS functionality for classifying and controlling the priority of Constant Bit Rate (CBR), high-priority data services and best-effort services. This ensures that latency-sensitive TDM traffic such as voice/pbx traffic has the highest priority service with minimal queuing. Deep queuing capabilities and large buffer memory ensures that the 7705 SAR can provide high priority classification for T1/E1 data traffic that may be less sensitive to delay and more sensitive to data loss than voice/pbx traffic. In the event of congestion, the system polices traffic flows to guarantee that lower traffic priorities are discarded before higher priorities. The 7705 SAR is fully supported by the 5620 Service Aware Manager. business access Services without boundaries Technology White Paper 15

20 5.4 Intelligent demarcation devices Demarcation is the process of creating separation or division between two adjacent networks. In the context of business access, it is the separation between the service provider s network (WAN) and the customer s network (LAN). An demarcation device (EDD), also known as a Network Interface Device (NID), serves a similar purpose to a traditional network termination unit (NTU) in a TDM network or a customer subscriber unit (CSU) in a frame relay network. Essentially, demarcation allows the service provider to test, monitor and assure services all the way to the customer premises, helping to ensure SLAs and controlling operating costs by minimizing line testing and site visits. This is particularly important as the number of customers, sites and services delivered increases. Figure 6 Intelligent demarcation device Customer premises Service provider domain Customer premises Userto-Network Interface (UNI) Networkto-Network Interface (NNI) Networkto-Network Interface (NNI) Userto-Network Interface (UNI) Customer switch Intelligent demarcation device Service provider Intelligent demarcation device Customer switch Due to the efforts of the MEF, the ITU-T and the IEEE in defining and standardizing OAM, demarcation devices located at the customer premises vastly improve service intelligence and help provide cost-effective, end-to-end service provisioning, management and assurance to meet more stringent SLAs. The EDD creates a clear network and service demarcation point between the service provider s and the customer s networks, helping to provide end-to-end visibility all the way to the customer premises. It also ensures that the service provider can isolate the customer network when testing and monitoring the end-to-end network connection and service to eliminate diagnostic errors caused by customer activities. Loopback testing allows service providers to diagnosis and repair network and service faults quickly and effectively without requiring on-site visits and test equipment, and without the need to wait for a suitable maintenance window. This helps reduce OPEX and CAPEX on test equipment and procedures as well as resulting in less repair time and equipment in the field. Loopback testing should include Layers 1 through 4 loopbacks, including MAC address, IP address and port swap, allow remote testing for business VPN Services. Typically, loopbacks can be established by VLAN, source or destination address, TCP/UDP port and service level, or any combination of parameters as defined in IEEE 802.3ah Link OAM, 802.1ag Connectivity Fault Management and ITU-T Y.1731 Performance Monitoring loopback procedures. Per-flow loopback and loopback testing in hardware ensures there is no interruption or degradation of customer traffic while tests are performed on selected flows. It is essential that EDDs provide wire speed performance as they are always in the data path. EDDs must therefore introduce negligible delay and jitter, and must be extremely reliable to avoid any impact on the services they support. For example, they should have no moving parts that could fail and have very reliable software architectures with built-in resilience. They must support intelligent testing, including loopback testing and filtering, monitoring and policing of bandwidth and traffic on a per-service basis. Ideally, they should support a higher level of granularity to enable 16 business access Services without boundaries Technology White Paper