advancement and use of metro ethernet services

8/12/2019 Advancement and Use of Metro Ethernet Services

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ADVANCEMENT AND USE OF

METRO ETHERNET SERVICESTOLULOPE WILLIAMS


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OUTLINE

Introduction

Basics of EthernetProtocols

Characteristics ofCarrier Ethernet

EvolvingArchitectures for

MetroEthernet/Packet

Transport Networks

Drivers formetro/carrier

Ethernet

Synchronizationover Packets

Conclusion

References


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INTRODUCTION

Ethernet was originally designed for simple data transfer

over local area networks.

Ethernet frame is made up:

7bytes of Preamble field

1byte of Start Frame Delimiter

6bytes of Destination Address

6bytes of Source Address

2bytes of Length/Type field 46-1500bytes of Protocol Data Unit

(PDU is made up of MAC Client Data and Pad and 4bytes of

Frame Check Sequence.)


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INTRODUCTION

Fig1: IEEE 802.3 frame structure


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INTRODUCTION

1972 Bob Metcalfe et al. develop first experimental 2.94

Mbps Ethernet at Xerox Parc (called alto aloha network,

1973, changed as ethernet)

1980 DEC-INTEL-XEROX present formal specifications for

10 Mbps Ethernet (Ethernet Blue Book) 1983 IEEE approves standard for 10 Mbps Ethernet over

coax cable

1989 International Organization for Standards (ISO)

approves Ethernet standard (ISO88023)

1990 Start-up Kalpana ships first full-duplex Ethernetswitch, the Etherswitch

1993 IEEE approves standard 10 Mbps Ethernet over fiber


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INTRODUCTION

1995 IEEE approves standard 100 Mbps Fast Ethernet

over twisted pair and fiber

1997 IEEE approves standard for full duplex Ethernet

1998 IEEE approves standard 1000 Mbps (Gigabit

Ethernet) over fiber and coax 2000 Nortel Networks announces first WAN-compatible 10

Gigabit Ethernet interfaces

2002 IEEE's 802.3 Ethernet standards group approved the

final draft of the 10 Gigabit Ethernet standard

2006 IEEE 802.3 High Speed Study Group (HSSG)

investigates 100Gbps Ethernet

2010 IEEE P802.3ba Ethernet Task Force ratified the final

draft of 40Gbps/100Gbps Ethernet


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INTRODUCTION

Fig2: Ethernet Evolution


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INTRODUCTION

Ethernet started as a bus topology on coaxial cables.

Later, Star topology on twisted pair copper cables.

Today we have Ethernet over fiber of different lengths and

Ethernet passive optical Networks.


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CHARACTERISTICS OF CARRIER ETHERNET

The MEF has defined Carrier Ethernet as a

ubiquitous, standardized, carrier-class Service and

Network defined by five attributes that distinguish

Carrier Ethernet from familiar LAN based Ethernet.

Standardized Services

Scalability

Reliability

Quality of Service

Service Management


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Standardized Services

E-Line: Point to Point Ethernet Service

E-LAN: Point to Multipoint Ethernet Service

E-Tree: Multipoint to Multipoint Ethernet Service

Ideally suited to converged voice, video & data networks

Wide choice and granularity of bandwidth and quality of

service options


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Scalability

The ability for millions to use a network service that is

ideal for the widest variety of business, information,

communications and entertainment applications with

voice, video and data

Spans Access & Metro to National & Global Services over a

wide variety of physical infrastructures implemented by a

wide range of Service Providers

Scalability of bandwidth from 1Mbps to 10Gbps and

beyond, in granular increments


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Reliability

The ability for the network to detect & recover from

incidents without impacting users

Meeting the most demanding quality and availabilityrequirements

Rapid recovery time when problems do occur, as low as

50ms


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Quality of Service

Wide choice and granularity of bandwidth and quality of

service options

Service Level Agreements (SLAs) that deliver end-to-endperformance matching the requirements for voice, video

and data over converged business and residential networks

Provisioning via SLAs that provide end-to-end performance

based on CIR, frame loss, delay and delay variationcharacteristics


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Service Management

The ability to monitor, diagnose and centrally manage the

network, using standards-based vendor independent

implementations

Carrier-class OAM

Rapid service provisioning


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Ethernet can be described in the context of three major

components: services aspects, network layer, andphysical

layer.

Fig3: Ethernet Layers

E A M


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EVOLVINGARCHITECTURES FOR METRO

ETHERNET/PACKET TRANSPORT

NETWORKS

QinQ/PB: VLAN Stacking

QinQ (802.1Q in 802.1Q) enables VLAN stacking, which

supports the appending of multiple VLAN tags to the

Ethernet frame to create a hierarchy, thus preserving

customer VLAN settings and providing transparencyacross a provider network.

QinQ is a way to overcome the limitations on the VLAN

identifier space.

QinQ has been standardized as 802.1ad (provider bridge)

E A M


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NETWORKS

Provider Backbone Bridge (802.1ah)

PBB is used to bridge several PBNs (802.1ad). In other

words, it allows the interconnection of multiple Provider

Bridge Networks while preserving customer VLANS.

It is also referred to as MAC-in-MAC.

It functions by turning off MAC learning, broadcasting

unknown and STP, and using a management plane (or

optionally a GMPLS control plane) to populate the switchbridging tables for a specific range of VID/MAC addresses.

E A M


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NETWORKS

PBB-TE: Provider Backbone Bridge Traffic

Engineering

Provider Backbone Bridge Traffic Engineering (802.1Qay)

eliminates broadcasting or flooding, by using only the loop-

free forwarding paths configured by management.

Uses a subset of PBB (no learning, no STP)

Forwarding is based on the static forwarding database

(FDB) entries; dynamic MAC learning is not used.

Tunnels carry raw Ethernet frames or 802.1ad.

E A M


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NETWORKS

Fig4: 802.1Q-in-802.1Q (Courtesy of www.h3c.com)

Fig5: PBB/PBB-TE

E A M


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NETWORKS

Fig6: 802.1Q QinQ/PB PBB/PBB-TE

EVOLVING ARCHITECTURES FOR METRO


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NETWORKS

MPLS-TP (MPLS Transport Profile)

MPLS-TP is transport technology combined with

Multiprotocol Label Switching (MPLS).

MPLS-TP or MPLS Transport Profile is a connection-

oriented packet-switched (CO-PS) application designed foruse as a network layer technology in transport networks.

MPLS-TP is to be based on the same architectural

principles of layered networking that are used in

longstanding transport network technologies like SDH,

SONET and OTN. MPLS-TP maps client signals into MPLS frames and

forwards those using mechanisms such as label switching

or label stack.

EVOLVING ARCHITECTURES FOR METRO


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NETWORKS

The payload convergence sub-layer is primarily responsiblefor encapsulating the payload in VC Protocol Data Units(VC-PDUs).

The sequencing sub-layer performs three functions: frameordering, frame duplication detection, and frame lossdetection.

The timing sub-layer performs two functions: clockrecovery and timed delivery.

IP services can be directly mapped into T-LSP or indirectlymapped by means of dual labels.

Fig7: MPLS-TP Generic Encapsulation Format


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DRIVERS FOR METRO/CARRIER ETHERNET

The optimal transition path toward Carrier Ethernet

depends on several parameters, including cost, technology,

scalability, operational impact and the carrier's existing

infrastructure.

Cost

Evolution of Transport Networks

Mobile Backhaul

Broadband Multi-play


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Cost

Ethernet offers the lowest cost per bit when compared to

TDM (SDH/PDH).

Overlaying Ethernet on SDH is more expensive thanEthernet over dark-fiber or Ethernet over WDM.

Carrier Ethernet platforms brings a significant cost saving

to the carriers by removing multiple layers of protocols

from hardware and software.


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Evolution of Transport Networks:

Mobile Backhaul

The Abis over IP solution enables operators to use IP and

Ethernet transport networks to connect RBSs to the BSCand thereby benefit from the lower costs of IP- and

Ethernet-based transport services.

In classic TDM-based Abis interface, the subordinate

16kbps timeslot on the Abis interface is permanentlyallocated to a traffic channel (TCH) for voice service and

will never be available to carry EDGE data.


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Evolution of Transport Networks:

Mobile Backhaul

With packet Abis the transport resources make up a

common pool that is used by the traffic offered at eachmoment in time.

The solution also opens the door to shared transport with

WCDMA and to integrated transport solutions for RBS

sites.


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Evolution of Transport Networks

Broadband Multi-play

Ethernet has ushered in a new era of one network,multiple services.

A single, familiar Ethernet interface enables convergence ofall services over a common network infrastructure,simplifying operations.

Ethernet services provide secure traffic separation and fullservice transparency, allowing the enterprise to maintainin-house control over routing information and security andencryption techniques.


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SYNCHRONIZATION OVER PACKETS

IEEE 1588-2008

IEEE 1588-2008, also known as Precision Time Protocol

(PTP) or IEEE 1588v2 enables network endpoint devices to

maintain precise timing and synchronization over

Ethernet/IP based networks.

IEEE 1588-2008 (PTP) enables accurate distribution of

time and frequency over packet-based networks.

PTP employs hardware-based time-stamping tosynchronize all real-time clocks distributed throughout the

packet network.


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IEEE 1588-2008

PTP employs server/client architecture.

The IEEE 1588 Grandmaster Clock is a primary reference

source for all of the PTP clients within its network domain.

The server continuously exchanges time-stamped packets

with its clients to ensure that they are all synchronized to

the same time and frequency reference point.


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Synchronous Ethernet (SyncE)

Previously, SDH and SONET gear were used in

conjunction with external timing technology to provide

accurate and stable frequency reference.

Using similar external references as a source, SyncE aims

to achieve the same function.

Synchronous Ethernet (SyncE) is the ability to provide

PHY-level frequency distribution through an Ethernet port.It can be considered one of the critical building blocks of the

NGN.


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CONCLUSION


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REFRENCES

IEEE Communications Magazine, March 2008, Vol.46,No.3

MEF, "Introducing the Specifications of the Metro Ethernet Forum".

Nortel Networks, "Service delivery technologies for Metro EthernetNetworks", White Paper

Muneyoshi Suzuki, "Requirements for 802.1AD Provider Bridges",June 2003.

Mick Seaman, "Large Scale Q-in-Q (1) Scalable address learning". MPLS-TP; http://en.wikipedia.org/wiki/MPLS-TP

Zhang Yongjun, Zhang Zhihui, Gu Wanyi Service Adaptation andLabel Forwarding Mechanism for MPLS-TP, ZTE white paper

Virtual Bridged Local Area Networks, IEEE 802.1Q, December1998

TDM to Ethernet Evolution: http://www.ecitele.com Cisco SyncE white paper: http://www.cisco.com

Ciena: White Paper - Delivering True Carrier Ethernet BusinessServices


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THANK YOU

advancement and use of metro ethernet services

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