GPON- Alcatel Lucent

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

Converging Voice, Data and Video in the Enterprise Using GPON

Abstract

As businesses contemplate how to increase bandwidth, enhance security and provide multiple services requiring different levels of priorities, they are faced with tough decisions on what to do with the existing cabling within the building. As speeds increase to a gigabit to the desktop, new Category 6 copper cables are often recommended for better transmission characteristics. Replacing the cables with new Category 6 cabling is a labor intensive and costly undertaking. As a network architect you understand that bandwidth requirements will continue to grow and eventually exceed a gigabit and drive toward 10 gigabits per second.

The logical alternative is to install a fiber-based distribution network that can handle speeds well beyond a gigabit. But even as you make that decision you have to choose the best optical technol-ogy to serve the many applications now being used by the modern workforce. There are a couple of alternatives, such as optical Ethernet switches or gigabit passive optical network (GPON) based technologies. This application note introduces the concept of using GPON-based optical technolo-gies to serve the needs of the modern-day business while providing a view of cost-effective evolution as speeds continue to increase.

Table of contents

1 Introduction

1 A little about GPON

2 GPON’s advantages

2 Robust security

2 Lower OPEX

2 Higher bandwidth

3 What does an FTTD network look like?

4 About Alcatel-Lucent GPON

4 Alcatel-Lucent 7342 OLT

4 Alcatel-Lucent ONTs

5 Alcatel-Lucent Indoor ONT I-020 model

5 Alcatel-Lucent Indoor ONT I-040 model

5 What is unique about Alcatel-Lucent GPON?

5 Continuing evolution

6 Summary

6 Acronyms

Converging Voice, Data and Video in the Enterprise Using GPON | Application Note 1

Introduction

Today’s corporate networks, government facilities and military installations are built using two, and sometimes three, separate copper architectures. One to carry data – typically a Category 5 cop-per network, a second to carry voice – typically a Category 3 copper network, and in some cases a third where coax delivers video. New technologies such as GPON are fully capable of supporting all of these services on a single fiber distribution architecture. The copper deployment model creates an environment that in today’s technology is wasteful and inefficient to maintain. GPON allows an operator to effectively deliver all of these services with the right user experience. Its Quality of Service (QoS) and high bandwidth capabilities are the mechanisms needed to converge voice, video and data all onto the same fiber network allowing more efficient maintenance, cabling and overall performance.

In addition to the installation of more switches and routers to address the continuous rise in bandwidth, redundant networks and equipment requirements have led to crowded equipment rooms, complex wiring closets and increased high-volume air conditioning (HVAC) requirements. Converging all of these services onto a single GPON distribution platform provides the bandwidth needed while significantly reducing the equipment, cabling and power required.

A little about GPON

Already deployed by many of the world’s largest Tier 1 telecommunications carriers, GPON has quickly established itself as the worldwide standard for delivering voice, data and video. Among other benefits, GPON provides an enormous amount of bandwidth — 2.5 Gb/s downstream and 1.25 Gb/s upstream — over a single strand of glass.

The technology consists of an optical line terminal (OLT) in the data center and a series of optical networking terminals (ONT) at or near the user’s desktop. Starting at the OLT, voice and data are transformed from an electrical format into optical signals. This traffic is then sent over the fiber network to the appropriate ONT, where it is separated back into electrical voice and data (see Figure 1). This architecture uses purely passive components such as splitters between the OLT and ONT, further reducing the chance of equipment failure.

The core underlying technology is still Ethernet, with GPON Encapsulation Mode (GEM) as the packaging format. GEM packages the IP packets efficiently with minimum overhead as they transit between the OLT and ONT. Each fiber can be shared by up to 64 ONTs, minimizing the amount of fiber required. Although multiple users share the passive optical network (PON), robust QoS and bandwidth mechanisms ensure that the traffic is correctly prioritized and that each user gets the required bandwidth.

Figure 1. GPON architecture

Subscribers

Wavelengthsplitter/combiner

OLT

Fiber in data center1310 nm

1490 nm

ONTs

Converging Voice, Data and Video in the Enterprise Using GPON | Application Note2

GPON’s advantages

GPON for fiber to the desktop (FTTD) offers some key advantages over Ethernet and current voice networks.

Robust securityFiber is inherently harder to tap into than a copper-based circuit. A fraudulent ONT cannot be spliced onto a fiber network, because the GPON system identifies each ONT based on pre-defined serial numbers and operator settings. Critics of fiber highlight the fact that all users receive the same downstream broadcast, creating the potential for eavesdropping. However, to counter this threat, PON employs a 128-bit advanced encryption scheme. The scheme incorporates a two-way key exchange, making it virtually impossible to intercept another user’s data. As well, any device used to tap into the fiber must be able to decipher GPON GEM ports and Traffic Containers (T-CONTs), which is not a typical function in standard Ethernet devices. All of these inherent capabilities make GPON a very secure environment for transporting sensitive data.

Lower OPEX Two different distribution networks are used in most corporate environments: one carries voice and the other carries data and video. In large enterprises this has led to congested wiring closets and equipment racks with daisy-chained switches. In addition, the mass of copper cables reduces air flow and necessitates increased cooling system requirements. With GPON, the voice and data net-work can easily be collapsed into one fiber infrastructure for all services. GPON technology offers tremendous economies of scale. One GPON chassis can support up to 4608 users on a 1:64 split of fiber. Typical deployments use a 1:32 split with 2304 users per chassis.

In most deployments, Ethernet switches are stacked in daisy-chains in an equipment closet. This creates a concentrated point for significant heat dissipation, requiring HVAC within the closet. With GPON systems a passive non-powered splitter is placed in the closet and removes HVAC concerns.

In addition, overall power requirements for an optical Ethernet solution equivalent to the GPON solution will be much higher. A typical Catalyst 388 port Ethernet switch with Gigabit Ethernet (GE) optical ports will have a minimum power supply of 1400 watts1 or 3.6 watts per port. A typical 12 port optical Ethernet switch is even less efficient at around 4.58 watts2 per port. A typical GPON OLT system serving 2304 users will have around 0.6 Watts per user – between nearly 6 to 7.6 times less power consumption.

Higher bandwidthIn most deployments, Ethernet is limited to 1000 Mb/s shared among many users. In one of the best case scenarios, 24 users are connected for an average of 41.7 Mb/s per user. More commonly, the switches are stacked in daisy-chains, significantly reducing true bandwidth per user for applications such as e-mail, access to graphics/video or databases. In GPON, the full downstream line rate of 2.5 Mb/s across 32 users delivers an average of 78 Mb/s per user – a 90 percent increase in available sustained bandwidth. When needed, an ONT can deliver up to the 1000 Mb/s.

In recent years, fiber has come to the forefront of communications as a secure, economical and scalable alternative to copper for enterprise and government applications. In particular, GPON has been widely adopted in North America as the leading fiber networking technology. It has typically been deployed for fiber-to-the-home (FTTH) applications, but it can equally serve large corporate environments in FTTD applications. For its part, FTTD can collapse the voice, data and video networks into one and has the potential to deliver virtually unlimited bandwidth while escaping the security constraints and operating expenditures (OPEX) of copper.

1 Based on Cisco Catalyst WS-C4510R-E Chassis 2 Cisco ME 3400G-12CS DC


What does an FTTD network look like?

In a campus environment, the typical approach is to locate the OLT shelf in the main building and then run fiber to the individual satellite buildings. In this case, the fibers reach splitters placed inside the buildings. The fibers in turn fan out at the splitters, reaching individual ONTs or users.To connect voice, data and video traffic back to the network core, the OLT offers multiple 1 Gb/s or multiple 10 Gb/s uplinks, providing bandwidth that can scale as your traffic demands rise. For a campus scenario, GPON is especially effective because it eliminates the need for active power con-suming equipment in the closets or basements of many of the buildings (see Figure 2).

A slightly different approach can be used for large buildings. In this environment, the OLT shelf is located in the basement with the fibers running up the elevator shaft or riser pipe. Splitters are located on each floor where the fibers fan out to individual users. The OLT uplinks are connected directly to edge routers in the basement (see Figure 3).

In either scenario, the GPON system can allow each PON to easily support up to 64 ONTs.

Figure 2. GPON in campus deployment

OLT IP PBX orSoftswitch

Corerouter

Splitter

Splitter

Splitter

Figure 3. GPON in large enterprise or building deployments

Core router

OLT IP PBX orsoftswitch


About Alcatel-Lucent GPON

Alcatel-Lucent is recognized worldwide as a leader in networking. Our flagship GPON platform, theAlcatel-Lucent 7342 Intelligent Services Access Manager Fiber to the Unit (ISAM FTTU), consists of an OLT and corresponding ONTs located at or near a user’s desktop.

Alcatel-Lucent 7342 OLTThe Alcatel-Lucent 7342 Optical Line Terminal (OLT) aggregates optical traffic and provides interfaces to edge IP-network switches and routers. Voice, data and IP video are delivered using a single fiber with two wavelengths (receive and transmit) multiplexed together. An optional third wave-length can be multiplexed for downstream radio frequency (RF) video over the same fiber. Each four-port PON line card can connect up to 256 ONTs, using 64 splits on each PON line. With support for 128 splits, Alcatel-Lucent can offer an unprecedented amount of capacity in a very small footprint, up to 512 ONTs per PON line card. This capacity minimizes the upfront capital investment because each GPON shelf can scale to support up to 4608 ONTs today and 9216 ONTs in the future.

To ensure maximum reliability, the Alcatel-Lucent 7342 OLT is designed with a redundant architec-ture and load-sharing switch matrix. Moreover, the system enables granular control of bandwidth, dy-namic bandwidth allocation and rate limiting features. Services are prioritized based on P-bit marking, with up to eight QoS classes and traffic schedulers. Through these unique features, each user can get the service quality they need – whether it is bursting up to the full line rate to send graphics, or having the right QoS for realistic video conferencing.

Alcatel-Lucent ONTsAlcatel-Lucent carries the largest portfolio of ONTs in the GPON industry – over 25 different types. Not only are these ONTs field-proven, but they support a wide range of services, even fax and modem. Below are two example models from the portfolio that are typical for business applica-tions. Many more may be applicable depending on the services and types of interfaces required (T1, POTS, RF, and so on.).

Services supported:

•High-speedInternet

•VoiceoverIP(VoIP)usingSIPorMediaGatewayControl(MEGACO)

•Video,includingIPTV,RFvideoandvideoondemand

•TDMservicessuchasPlainOldTelephoneService(POTS)andT1service

•T.38faxsupportandmodem

•VLANtagandprioritybitmanipulation


Alcatel-Lucent Indoor ONT I-020 modelThe Alcatel-Lucent Indoor Optical Network Terminal (ONT) I-020 model is a compact and cost-effective ONT that offers both cost savings and minimal space requirements. The Alcatel-Lucent Indoor ONT I-020 comes with two 10/100/1000 ports and is powered through a DC adapter. The ports can go to two different PCs or one port can be assigned to a Session Initiation Protocol (SIP) phone and the other port to a PC. The Alcatel-Lucent Indoor ONT I-020 can be wall mounted or placed near or on the desktop.

Alcatel-Lucent Indoor ONT I-040 modelThe Alcatel-Lucent Indoor ONT I-040 model is an ONT with four 10/100/1000 ports and is powered through a DC adapter. Individual ONT ports can be bridged to create a LAN or can be shared between separate users. The Alcatel-Lucent Indoor ONT I-040 can be wall mounted or placed near or on the desktop.

What is unique about Alcatel-Lucent GPON?

• Market leadership: Alcatel-Lucent supplies the majority of GPON equipment needs for the world’s largest Tier 1 carriers; the company has shipped more GPON ports than any other vendor. A variety of customers, including telephone providers, municipalities, utilities and real estate developers, rely on the Alcatel-Lucent 7342 ISAM FTTU for their private and public networks.

• Enterprise experience: In addition to GPON, Alcatel-Lucent also offers a wide range of equipment for the enterprise market, such as Ethernet switches, routers and IP-Private Branch Exchanges (PBXs). All of these products have been designed and tested to work as an integrated solution in a private network. Depending upon individual requirements, customers can choose an end-to-end solution or individual components without worrying about reliability and integration issues.

• Unparalleled ONT portfolio: Alcatel-Lucent has the extensive range of ONTs (over 25 models) for various applications, from business and residential to outdoor or indoor use. Unique perfor-mance management features such as Receive Signal Strength Indicator (RSSI), make maintain-ing and troubleshooting ONTs easier.

• Extensive service support: Whether it is traditional voice, IP voice, IP video, RF video, T1 or fax or simple Internet access, Alcatel-Lucent GPON delivers. Alcatel-Lucent GPON supports nearly any service demand with the right QoS through its sophisticated traffic prioritization and management capabilities.

Continuing evolution

As the bandwidth continues to expand, GPON technology is also expanding. Ten gigabit per sec-ond GPON standards are being developed now. These standards will allow the smooth evolution of today’s GPON systems to 10 Gb/s symmetrical GPON systems. Alcatel-Lucent is in the forefront of these technologies and working with the standards bodies to ensure that Alcatel-Lucent can bring the best 10 G GPON products to the marketplace.


Summary

In large institutional settings and campus environments, an FTTD architecture using GPON makes a compelling network alternative. FTTD offers a wide range of cost and power saving opportunities compared to copper and optical Ethernet networks. A GPON-based FTTD solution collapses voice, data and video networks into one while overcoming the security constraints and evolution issues as-sociated with copper networks. The Alcatel-Lucent 7342 ISAM FTTU is a feature-rich product that has earned the endorsement of users and network administrators alike.

Acronyms7342ISAMFTTU 7342IntelligentServicesAccessManagerFibertotheUnit

7342 OLT 7342 Optical Line Terminal

ONTI-020andI-040 IndoorOpticalNetworkTerminalI-020andI-040models

CAC connection admission control

E-line Ethernet line

FTTD fibertothedesktop

FTTH fibertothehome

GE Gigabit Ethernet

GEM GPONEncapsulationMode

GPON gigabit passive optical network

HVAC high-volumeairconditioning

MEGACO MediaGatewayControl

OLT optical line terminal

ONT optical network terminal

OPEX operatingexpenditures

PBX PrivateBranchExchange

PON passive optical network

POTS Plain Old Telephone Service

QoS Quality of Service

RF radiofrequency

RSSI ReceivedSignalStrengthIndicator

SIP SessionInitiationProtocol

VoIP VoiceoverInternetProtocol

www.alcatel-lucent.com Alcatel, Lucent, Alcatel-Lucent and the Alcatel-Lucent logo are trademarks of Alcatel-Lucent. All other trademarks are the property of their respective owners. The information presented is subject to change without notice. Alcatel-Lucent assumes no responsibility for inaccuracies contained herein. Copyright © 2009 Alcatel-Lucent. All rights reserved. CPG9718090103 (04)

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