Long Reach Ethernet - LRE

1© 2000, Cisco Systems, Inc. 1

Long Reach Ethernet - LRELong Reach Ethernet - LRE Long Reach Ethernet - LRELong Reach Ethernet - LRE


Challenges to OvercomeChallenges to Overcome

• Overcome Ethernet distance limitation

• More bandwidth over Category 1/2/3

support advanced media-rich applications

• Drive down per-line costs while driving up performance by utilizing Ethernet components

• Retain key QoS, security, provisioning and management features

• Ensure equipment is easy to use and provides platform for future applications


Technology Solution: LRE (Ethernet Technology Solution: LRE (Ethernet Over VDSL) Over VDSL)

• 5, 10 or 15 Mbps symmetric throughput

Maps directly to full duplex Ethernet

Allows for true high speed BANs

• Co-exists with POTS and digital phones

Requires splitter

Up to 5000 ft over single pair Cat 3

Runs over Cat 1, 2 as well unstructured wiring

• Based on robust Catalyst switching platform


Solution Components Solution Components

Catalyst 2924-LRE-XL Switch

Cisco 575-LRE CPE

PS-1M-LRE-48 POTS Splitter

10/100 L2 or L3 Ethernet switch: Stack aggregator

Cisco Building Broadband Service Manager (Radius Authentication, NAT, DHCP, DNS, User Self-Activation, Dynamic Bandwidth

Selection), Third-party Account/Billing


Catalyst 2900-LRE-XLCatalyst 2900-LRE-XL

• Based on industry leading Catalyst 2900-XL platform

• IOS Based

• 802.1Q VLANs

• 802.1p COS

• ManagementCLI

Embedded web console

CPE Monitoring

Switch Clustering

• SecurityPrivate VLAN Access (unicasts to uplink port only)Multicast controlTACACS+ (management authentication)

• 12 or 24 LRE Ports (RJ21)• 4 10/100 Ethernet Ports

(RJ45) For stacking or connection to router or server

• 1 RU High


Cisco 575-LRE CPECisco 575-LRE CPE

• Converts VDSL to standard Ethernet

• Integral POTS splitter for telephone attach

Passive function

• 2 RJ11s for Line input and telephone

Supports 2-line phones

• 1 RJ45 for Ethernet

• Monitoring remotely from switch using web interface or CLI


PS-1M-LRE-48 POTS SplitterPS-1M-LRE-48 POTS Splitter

• Non-homologated version

• Supports 48 ports

• No power supply - Passive device

• 1 RU High

• ADC & Corning to provide homologated splitter

Requires specific splitter


LRE OverviewLRE Overview

Add-on as Needed

Main Closet

PBX

POTSSplitters

LRESwitches

InternetRouter

Management Gateway

Floor 1

Floor 2

Floor 3

Floor 4

Floor 5

Up to 4000’


LRE Room DetailLRE Room Detail

Main Closet

PBX

POTSSplitter

LRE Switch

InternetRouter

ManagementGateway

Guest Room PC Connection

Up to 4000’ Existing Phone Wiring


LRE EQUIPMENT LAYOUTLRE EQUIPMENT LAYOUT


LRE EQUIPMENT LAYOUTLRE EQUIPMENT LAYOUT


LRE Technology OverviewLRE Technology Overview

• Enables the use of Ethernet over existing, unconditioned, telephone-grade wire

• Enables Ethernet to coexist with “plain old telephone service” (POTS), Integrated Services Digital Network (ISDN) or private branch exchange (PBX) signaling services

• Uses DSL coding and digital modulation techniques with Ethernet

• Provides a point-to-point transmission that can deliver a symmetrical, full duplex, data rate of up to 15 Mbps

• LRE products are simple to install and interface with any existing Ethernet solution


LRE Technology—BandwidthLRE Technology—Bandwidth

• LRE technology can operate at up to 17 Mbps

Enables transport of Ethernet data up to 15 Mbps

• Transport overhead does not reduce the Ethernet bandwidth


Standard xDSL Frequency BandsStandard xDSL Frequency Bands

Downstream-1

138 kHz

3.75 MHz

12 MHz5.2 MHz

8.5 MHz

Upstream-1

Downstream-2

Upstream-2

• Upstream and downstream transmissions separated by frequency (FDD)

• 4 bands gives more flexibility for performance vs reach


LRE Frequency BandsLRE Frequency Bands

DownstreamTX - SwitchRX - CPE

UpstreamRX - SwitchTX - CPE

900 KHz 3.75 MHz 9 MHz5.2 MHz

• Downstream band reduced to allow use of digital “SmartPhones”

• Upstream band may use standard frequencies or may use wider band for “private” installations

• Maximum data rates 15Mb/s full duplex (private) or 15/5 for standard installations


Summary of LRE Key Technology Summary of LRE Key Technology Features Features

• Standard 10 Mbps Ethernet over regular twisted pair copper wire

• Distances of up to 4000 ft (1.2 km) at full-duplex 10 Mbps, 15 Mbps high-speed mode (3500 ft, 1 km)

• Simultaneous data and POTS, ISDN or PBX signaling services over the same line

• Utilizes the most advanced multi-QAM modulation techniques

• Minimum interference with other wire pairs and other services

• Full-duplex point-to-point transmission

• Longer distances can be reached at lower rates

• Low power-implementation, minimum heat-dissipation issues

• Supports testing and management capabilities


Design ExamplesDesign Examples


Broadband Ethernet Solution Broadband Ethernet Solution Hotel Telecommuter DesignHotel Telecommuter Design

Cisco 1700/2600

POTSSplitter

CPE

Catalyst2924-LRE

Catalyst2900 XL

LRELRE

Room 1

CPE

Room 2

Catalyst2900 XL

- Local services/intranet- Video Servers

Conference Room

Aironet340

Long Reach Ethernet

Internet/VPN

VPN VPNVPN

PSTN Network

PBX

Cache Engine (Optional)

POTS Phone

LRELRE LRELRE

BBSMAccounting/Billing/Security


Cisco1700Cisco

1700

POTSSplitter

Multi Dwelling UnitMulti Dwelling UnitGigabit to the Central OfficeGigabit to the Central Office

Catalyst2924-LRE LRELRELRELRE

Catalyst 6500

GSR

Central Office

Catalyst3512 XL

Telecommuter

Aironet

CPE

ApartmentTelecommuter

CPE

Apartment

Aironet

VPNVPN

LRELRELRELRE

LRELRELRELRECPE CPE

PSTN Network

Documents

Long Reach Ethernet - LRE