Carrier Ethernet

CARRIER ETHERNET
FEBRUARY 2013
By Eng. Anuradha Udunuwara,
BSc.Eng(Hons), CEng, MIE(SL), MEF-CECP, MBCS, ITILv3 Foundation, MIEEE, MIEEE-CS, MIEE, MIET, MCS(SL), MSLAAS

Agenda
 What is Ethernet?
 What is Carrier Ethernet?
 Why Carrier Ethernet?
 Standards
 Technology neutral
 Technology specific
(c) Anuradha Udunuwara

What Do We Mean By “Ethernet?”
 Ethernet as an interface
 Ethernet as a point-to-point link
 IEEE 802.3 view
 Ethernet as a Packet Switched Network (PSN) infrastructure (transport)
 IEEE 802.1 (bridging) view
 ITU-T SG15 / SG13 managed Ethernet network view
 Ethernet as a protocol
 Ethernet as a service
 MEF view – user-to-user transfer of 802.3 frames over any transport layer
 E-Line, E-LAN, E-Tree, E-Access

Legacy Ethernet (10-Mbps)
Source: http://learn-networking.com/network-design/a-brief-overview-of-ethernet-history
(RG-58)
(RG-8)
(Cat 3 and above)
500 m
185 m
100 m
Max. Segment Length

5-4-3 Rule
10-Mbps Ethernet could
be used on no more than
5 network segments, 4
repeaters, and no more
than 3 of the five network
segments can be for end-
users.
Source: http://xvongola.blogspot.com/2011/09/aturan-5-4-3-dan-aturan-5-4-3-2-1-pada.html

History
 1973.5.22 - 1st document
 1975 -Xerox gets patent
 1976 - deployed at Xerox
 1980 - DIX (Digital/Intel/Xerox) standard
published (The Ethernet, A Local Area Network.
Data Link Layer and Physical Layer
Specifications_v1)
 1982 - v2
 1982 - IEEE 802.3 CSMA/CD standard
approved (Other options: Token Ring and Token
Bus)
 1983 – IEEE 802.3 CSMA/CD Draft Published
 1985 – IEEE 802.3 CSMA/CD Standard
published
Source: http://www.windowsnetworking.com/articles-tutorials/netgeneral/history.html

History, Cont.,
Source: http://learn-networking.com/network-design/a-brief-overview-of-ethernet-history

The inventors
Charles P. Thacker
Butler Lampson
Source : http://research.microsoft.com/en-us/um/people/blampson/Source: http://calendar.cs.cmu.edu/dlseries/6235.html
Source: http://www.computerhistory.org/revolution/networking/19/381/2158
Bob Metcalf David Boggs

The Basic Ethernet Bus
Thinet coaxial cable
Disconnecting a single connection will bring the whole network down!
Source : http://www.datacottage.com/nch/eoperation.htm

Using a Hub
• Bus - >Star
• Collisions still possible
• Centralized wiring
• Can automatically bypass any ports that are disconnected or have a cabling fault
• -> network much more fault tolerant than a coax based system

Using a Switch
• To overcome the problem of collisions and other effects on network speed
• Machines can transmit simultaneously

IEEE 802

IEEE 802, Cont.,
Some examples
802.1 Bridging (networking) and Network Management
802.2 Logical link control (upper part of data link layer)
802.3 Ethernet (CSMA/CD) (defines the physical layer and data link layer's MAC of
wired Ethernet)
802.17 Resilient packet ring
802.11 Wireless LAN & Mesh (Wi-Fi certification)
802.15 Wireless PAN
802.15.1 Bluetooth certification
802.15.4 ZigBee certification
802.16 Broadband Wireless Access (WiMAX certification)
802.16e (Mobile) Broadband Wireless Access
802.20 Mobile Broadband Wireless Access

IEEE 802.3
802.3a 10BASE2 10 Mbit/s over thin Coax
802.3i 10BASE-T 10 Mbit/s over twisted pair
802.3j 10BASE-F 10 Mbit/s over Fiber-Optic
802.3u 100BASE-TX, 100BASE-T4, 100BASE-FX Fast Ethernet at 100 Mbit/s w/auto-negotiation
802.3x Full Duplex and flow control
802.3y 100BASE-T2 100 Mbit/s over low quality twisted pair
802.3z 1000BASE-X 1 Gbit/s Ethernet over Fiber-Optic
802.3ab 1000BASE-T 1 Gbit/s Ethernet over twisted pair
802.3ac Max frame size extended to 1522 bytes (to allow "Q-tag")
802.3ad Link aggregation for parallel links
802.3ae 10 Gbit/s Ethernet over fiber; 10GBASE-SR, 10GBASE-LR, 10GBASE-ER, 10GBASE-SW, 10GBASE-LW, 10GBASE-EW
802.3af Power over Ethernet (12.95 W)
802.3ah Ethernet in the First Mile
802.3an 10GBASE-T 10 Gbit/s Ethernet over UTP
802.3at Power over Ethernet enhancements (25.5 W)
802.3av 10 Gbit/s EPON

IEEE 802.1
802.1w-2001 Rapid Reconfiguration of Spanning Tree (RSTP)
802.1D-2004 MAC Bridges (rollup of 802.1w)
802.1s-2002 Multiple Spanning Trees (MSTP)
802.1v-2001 VLAN Classification by Protocol and Port
802.1Q-2005 VLAN Bridges (Rollup of 802.1s and 802.1v)
802.1ad-2005 Provider Bridging (PB)
802.1ag-2007 Connectivity Fault Management (CFM)
802.1ah-2008 Provider Backbone Bridge (PBB)
802.1aq-2012 Shortest Path Bridging (SPB)
802.1Qay-2009 Provider Backbone Bridge Traffic Engineering (PBB-TE)
802.1Q-2011 VLAN Bridges (Rollup of 802.1Q-2005+Cor-1 and 802.1ad/ag/ah/Qay)
802.1X-2010 Port Based Network Access Control

IP vs Ethernet
 wrong questions to ask
 Which is better – IP or
Ethernet?
 Which is cheaper?
 Is Ethernet going to take
over from IP?
 Or will IP win out in the
end?
• Answers
– Ethernet and IP will co-exist
– Complimenting each other
– Meeting different needs
– Both occurring in hybrid networks
– Delivered over a single, global
platform
– Sharing similar cost and service
characteristics

Why Ethernet ?
 Most common Interface today
 Cost effective
 Supports very high Bandwidths (upto 100 Gbps)
 Flexible upgrades within a wide range (ex: 1Mbps to 1Gbps)
 Easy and simple to manage and maintain
 Variable payload support

Global Expansion from Metro to Carrier Ethernet
 The Beginning: Metro Ethernet (ME)
 MEF was formed in 2001 to develop ubiquitous business services for Enterprise
users principally accessed over optical metropolitan networks to connect their
Enterprise LANs
 Expansion to CE
 Success of ME Services caught the imagination of the world as the concept
expanded to include
 Worldwide services traversing national and global networks
 Access networks to provide availability to a much wider class of user over
fiber, copper, cable, PON, and wireless
 Economy of scale from the resulting converged business, residential and
wireless networks sharing the same infrastructure and services
 Scalability & rapid deployment of business applications
 Adoption of the certification program
 While retaining the cost model and simplicity of Ethernet

What is Carrier Ethernet (CE)?
 Is it a service, a network, or a technology?
 Answer for an end-user
 It’s a Service defined by 5 attributes
 Answer for a service provider
 A set of certified network elements that connect to
transport CE services for all users, locally &
worldwide
 It’s a platform for value added services
 A standardized service for all users(c) Anuradha Udunuwara

MEF CE Definition
A ubiquitous, standardized, carrier-class Service and
Network defined by 5 attributes that distinguish it
from familiar
LAN based Ethernet

Why Ethernet in the Metro?
10/100
Base -T
 Enables true extension of Enterprise LAN across multiple locations, as well
as effectively providing other multipoint services
 Utilize simplicity and ubiquity of Ethernet as a technology
 Enables bandwidth efficiency in the network due to statistical multiplexing
 Low price/bandwidth ratio makes Ethernet the technology of choice
Ethernet Ethernet

Attribute 1: Standardized Services
CEEnterprise Ethernet
 Provide service across multiple
geographies and multiple networks
 Provides service to multiple customers
 Needs to provide converged transport
with optimal use of present investment
 Service provided over one
network (Company LAN)
 One customer – can
customize network to
requirements
Network 1
Network 2
Network 3

1000
Nodes
Attribute 2: Scalability
 Need to scale to millions of
nodes
 Need to scale from few Mbps
data rate to 10 Gbps and beyond
 Network needs to support
several services
 Few hundreds or
thousands of nodes
 Need to scale from 10
Mbps to 1 Gbps
 Limited number of
services to be supported
CEEnterprise
Ethernet
100
Nodes
100 Mbps
1 Gbps
100
Nodes
100 Mbps
1000
Nodes
1 Gbps
10 Gbps
10K
Nodes
100 Gbps
10M
Nodes

Attribute 3: Reliability
 Need to provide protection
in case of link failure in less than
50 ms
 Need to provide five 9s reliability
of equipment
 Need to recover from faults as
quickly as possible to provide
uptime as specified in SLA
 Equipment is all within a premise,
more reliable with easy recovery
 No strict time limits needed on link
protection, no SLAs associated with
network availability
CEEnterprise
Ethernet $$$$ $$
SLA losses
50ms protection

Attribute 4: Service Management
 Need to quickly monitor and
diagnose faults across multiple
vendor equipment
 Ability to rapidly provision the
bandwidth end-to-end
 Fault isolation is easy
since equipment is all
within a premise
 Bandwidth is more static
in nature, no need for
provisioning
CE
Enterprise
Ethernet
Service
Down
Vendor 1
Vendor 2
Vendor 3
Service
Down

Attribute 5: Quality of Service
 Bandwidth is cheap,
hence no contention
in the network
 No variety in traffic
profiles, identical
treatment is
acceptable
Enterprise
Ethernet
High-speed
Mobile Internet
Mobile Voice
Enterprise
Services
Leakage of SLA-based
traffic due to congestion
Metro
Network
High-speed Mobile
Internet
Mobile Voice
Enterprise
Services
Metro
Network
 QoS absolutely required to
service variety of SLAs
 Ability to treat customer traffic
in agreement with the SLAs
CE

Equipment
Transport
Technologies
Availability
End Customer
Geographic
Reach
In summary
Ethernet in LAN CE
Department heads
Employee
Some tolerance for disruption
Cat5 Fiber
Wireless
Campus
Building
Wiring closet
Metro
National
International
Service-oriented
Highly resilient
Carrier environmental
Fiber T1/E1, T3/E3
Cat5 SONET/SDH
Cu Wireless
No tolerance for disruption
Driven by SLA
Corporate IT
Consumer

Other CE Network (CEN) requirements
 Availability
 Stability
 Performance
 Multicast support
 TDM support
 Security

Availability (Resilience)
Hardware Component of CE Node High Availability mechanism
Route processor 1:1
Switching fabric 1:1
Power supply 1+1 Note
Power feed 1+1 Note
Cooling system 1+1 Note
Any other control plane module 1:1
Any other switching plane component 1:1
Note : single component shall be able to take the full load of the CE node

Availability (Resilience), Cont.,
 ITU-T G.8032 version 1 & 2 (ERPS)
 Following software level high availability features shall be implemented;
 NSR for
 LDP
 RSVP TE
 BGP
 OSPF
 PIM-SM and PIM-SSM
 ISSU
 BFD requirement shall be analyzed for following in the future stage
 LDP
 RSVP
 BGP
 OSPF
 PIM-SM and PIM-SSM
 NSF requirement shall be analyzed in future stage

Stability
 Stability of the CEN and its NE are very
important. This should ensure consistent
performance of the NE
 MTBF and MTTR values shall meet
99.999% node availability
requirements

Performance
 Scalability of the CEN determine by providing
sufficient bandwidth to be able to guarantee a
committed level of performance for the full service
portfolio of end users.
 CEN shall be designed to achieve the certain QoS
requirements/KPIs defined with the set of
services/products.
 CEN must be able to handle unpredictable surges in
traffic, and appropriate load

Multicasting
 To support IPTV and other multicast applications,
the CEN shall support IP multicast protocols
 Layer 3 based (PIM) multicast technology is
preferred over Layer 2 technology for scalability
and flexibility reasons
 Layer 2 multicasting features shall be available
for customer multicasting services

TDM Circuits
(e.g. T1/E1 Lines)
Supporting TDM services
 Enables TDM Services to be transported across Carrier
Ethernet network, re-creating the TDM circuit at the far
end (Circuit Emulation Services (CES) over CE)
 Runs on a standard Ethernet Line Service (E-Line)
 Use Synchronous Ethernet or IEEE 1588v2 for frequency
and time of day synchronization
Carrier Ethernet Network
TDM Circuits
(e.g. T1/E1 Lines)
Circuit Emulated
TDM Traffic

Security
 The CEN addresses the security which provides
confidentiality, integrity and availability of specific
services. The following areas are identified and shall
be equipped with necessary security mechanisms,
 Node security
 Access security
 Interconnection security – UNI and I-NNI
 Protocol security – UNI and I-NNI

Why CE Generations?
 Clearly communicate the Carrier Ethernet evolution
and the value it brings to the market
 Maximizes investment made by the industry
 Provides a directional roadmap for the industry

CE Generations Framework

Service Characteristics over 8 Services

CE Service Types

CE Service Matrix
Source: http://metroethernetforum.org/page_loader.php?p_id=2262

Today’s world demands
 Any application, any connectivity, on any device
 Information, voice, video or data
 Entertainment – video voice, data any source
 At home, in the office, on the go, seamlessly and always
connected
 Any time, 24/7/365, on demand
 All delivered on one ubiquitous high performance, global
service.

Issues with Legacy Networks
 Low bandwidth
 No flexibility to scale
 High cost of installation
 Slow provisioning
 Bandwidth growth inflexible/non-linear
 Limited by multiplexing hierarchy
 TDM-based access: inefficient for converged data

CE Value Propositions
 Lower per-user provisioning costs
 Technically simple relative to TDM ckts.
 Due to large installed base
 Efficient and flexible transport
 Wide range of speeds: 1 Mbps--10 Gbps
 QoS capabilities
 Ease of inter-working
 Plug-and-play feature
 Ubiquitous adoption
 The technology of choice in enterprise networks

Ethernet Business Drivers
 Business connectivity
 Storage networks
 Data centers
 Video conferencing
 Residential services
 Triple-play services (IPTV)
 On-line gaming
 High-speed Internet access
 Wireless backhaul
 Reduced cost, complexity for mobile operators

CE Market
 Services Revenue : $5B (2012) to over $11B (2017) [Insight Research]
 Equipment Revenue: $31.7B (2011) to $42B (2016) [Infonetics]
 CE Equipment spend: $186 billion over next 5 years!

According to all wireless operators,
delivering the bandwidth required
in the 4G-LTE wireless backhaul is
“the single biggest challenge and
operating cost in the industry.”

Mobile Backhaul Migration
Source : http://www.edn.com/design/test-and-measurement/4405540/Mobile-backhaul-transition-required-for-wireless-services

Multiple Generations of Mobile Backhaul
2G
3G
4G
Gateway
RNC
BSCAccess
Device
User to Network Interface (UNI)
MBH Generic Interworking Function (GIWF) – Ex: MEF 3/8
BTS
NodeB
eNodeB (LTE)
BS (WiMAX)
Eth Carrier
Ethernet

Part of International Standards Community
Working inward
from the edge
Working
outward
from the
core
Making it work
together
MEF’s role is largely additive to these organizations, developing necessary additional specifications that are
required to enable CE.
MEF also provides inputs in support of CE to these bodies via its participating members and liaisons.
It is not within the scope of the MEF to endorse or otherwise the work of other standards bodies and associations

EducationStandards Compliance
Accelerating the
Global Adoption of
CE Networks
and Services
MEF: Defining Body of CE
• 186 Member Companies
• 92 Service Providers
• Global Representation

CE: Scope of MEF Work
SoHo & Residential Triple-PlaySmall/Medium BusinessEnterprise Clients Mobile data/video
HD TV, TVoD, VoD,
Content Providers
Video
Source
Gaming, DR, ERP Voice/Video
Telephony
Internet information
& Software apps
Host applications,
Consolidated Servers
Carrier Ethernet
CE wire-line and mobile backhaul
with copper, fiber , cable, wireless access network delivery

CE Architectural Components
End
User
Customer
Network
CEN
Customer
Network
End
User
UNI Reference Point UNI Reference Point
Ethernet Virtual Connection
End-to-End Ethernet Flow
(unidirectional)
End user Interface End user Interface

Application Service Layer
Ethernet Service Layer
Transport Service Layer
(ex:- 802.1, SONET/SDH, MPLS)
CEN Layer Model

Service Attributes
 Physical Interface
 Medium, speed, mode, MAC layer
 Traffic Parameters
 CIR, CBS, PIR, MBS
 QoS Parameters
 Availability, delay, IFDV, loss
 Service Multiplexing
 Multiple instances of EVCs on a given physical I/F
 Bundling
 Multiple VLAN IDs (VID) mapped to single EVC at UNI

Services Using E-Line Service Type
Ethernet Private Line (EPL)
 Replaces a TDM Private line
 Port-based service with single service (EVC) across dedicated UNIs providing site-to-
site connectivity
 Typically delivered over SDH (Ethernet over SDH)
 Most popular Ethernet service due to its simplicity
Point-to-Point EVCs
Carrier Ethernet
NetworkCE UNI
CE
UNI
CE
UNI
ISP
POP
UNI
Storage
Service
Provider
Internet

Services Using E-Line Service Type
Ethernet Virtual Private Line (EVPL)
 Replaces Frame Relay or ATM L2 VPN services
 To deliver higher bandwidth, end-to-end services
 Enables multiple services (EVCs) to be delivered over single physical connection (UNI) to customer
premises
 Supports “hub & spoke” connectivity via Service Multiplexed UNI at hub site
 Similar to Frame Relay or Private Line hub and spoke deployments
Service
Multiplexed
Ethernet
UNI
Point-to-Point EVCs
Carrier Ethernet Network
CE
UNI
CE
UNI
CE
UNI

Services Using E-LAN Service Type
 EP-LAN: Each UNI dedicated to the EP-LAN service. Example use is
Transparent LAN
 EVP-LAN: Service Multiplexing allowed at each UNI. Example use is
Internet access and corporate VPN via one UNI
Ethernet Private LAN
example
Multipoint-to-Multipoint
EVC
Carrier
Ethernet
NetworkCE
UNI
CE
CE
UNI
UNI
Ethernet Virtual
Private LAN
example
Multipoint-to-Multipoint
EVC
Carrier
Ethernet
Network
CE
UNI
CE
CE
UNI
UNI
Point-to-Point EVC
(EVPL)
UNI
CE
ISP POP
Internet

Services Using E-Tree Service Type
Carrier Ethernet
Network
CE
UNI
UNI
CE
CE
Leaf
Leaf
UNI
CE
Leaf
Rooted-Multipoint EVC
Ethernet Private Tree
example
UNI
Root
EP-Tree and EVP-Tree: Both allow root - root and root - leaf communication but
not leaf - leaf communication.
• EP-Tree requires dedication of the UNIs to the single EP-Tree service
• EVP-Tree allows each UNI to be support multiple simultaneous services at the
cost of more complex configuration that EP-Tree
Root
Ethernet Virtual Private
Tree example
CE
CE
CE
UNI
UNI
UNI
Rooted-Multipoint
EVC Multipoint to
Multipoint EVC

Interconnecting autonomous, Carrier Ethernet networks, locally,
regionally, nationally, globally
Enabling…
– Standardized, streamlined delivery of MEF-certified Carrier Ethernet
services over multiple, connected, Carrier Ethernet networks
– End-to-end Class of
Service, Management
and Protection
– Ubiquitous service
delivery
MEF Global Interconnect

Interconnect Technical Components
Interconnect elements required to enable globally connected Carrier Ethernet
services
The MEF Global Interconnect specifications ensures support for all Carrier Ethernet attributes
between service providers
ENNIUNI UNI
Service Provider Service ProviderEnd User End User

4 Technical Areas
MEN A MEN B
Services (Subscriber)
User Network
Interface (UNI)
Architecture
Management (Fault and Performance)
Test (Abstract Tests for Certification)
Services (Operator)
External Network
Network Interface
(ENNI)

MEF Services
Certification Program

57 MEF Certified Providers
Worldwide Adoption of Service Certification
MERICA

MEF Certifications for Services
Program certifies three most widely deployed Carrier
Ethernet services:
• EPL dedicated service that interconnects two sites
• EVPL multiplexed service that interconnects a hub to
multiple remote sites
• E-LAN meshed service that interconnects multiple
sites
Two major certifications validate service compliance and
performance:
• MEF 9 validates end-to-end service delivery and
functionality
• MEF 14 validates service performance and traffic
management
EPL Service
Ethernet Private Line
EVPL Service
Ethernet Virtual Private Line
ELAN Service
Ethernet LAN
MEF 9
MEF 14
Certifications

Frequently Asked Questions
Does my company need to be a MEF member prior to certification?
• MEF membership is a pre-requisite to certification
• Not renewing MEF membership does not invalidate certification
For how long are certifications valid?
• Certifications have unlimited validity in time for services delivered across the same type of UNI equipment
deployed at the time of testing
• Certifications of new services or services delivered across UNIs or MENs deploying new equipment,
software releases or transport technologies are at will
Who should I contact to find out more?
• Iometrix is the MEF authorized certification lab since 2005
• Contact certification@iometrix.com or visit www.iometrix.com

MEF Equipment

83 Certified Equipment Vendors
MEF Certification Lab
July 2011
800+ products certified worldwide

Benefits of Certifying Equipment
• Sales Benefits
• Requirement in growing number of service provider RFPs
• Provides competitive advantage over non-certified equipment
• Builds buyer confidence and speeds up sales process
• Marketing Benefits
• Widely recognized by service provider and enterprise customers
• Aligns product portfolio with CE industry standards
• Ensures high level of consistency in products & services
• Technical Benefits
• Single testing process saves time / costs on conformance testing
• Facilitates multi-vendor deployments
• Supports service provider services certification

MEF Certifications for Equipment
Program certifies wide range of products
supporting CE services:
• Focus on key CE capabilities deployed by service
providers:
− CE service delivery and performance at the UNI
− TDM services delivered over Ethernet for mobile
backhaul
MEF 9 Certification
244 Test Cases
Ethernet Service at the UNI
MEF 14 Certification
170 Test Cases
Traffic Management at the UNI
MEF 18 Certification
334 Test Cases
CES over Ethernet

MEF Professional

Benefits CE Organizations
• Principle organizations
• Service providers
• Equipment vendors
• Benefits
• Demonstrates to customers and partners an employer’s
commitment to quality and knowledge of Carrier Ethernet
knowledge, skills and capabilities
• Enhances employer training requirements
• Improves employer candidate assessment process
• Valuable complement to MEF services and equipment
certification achieved by the organization

Benefits CE Industry
• Availability of more recognized CE professionals
accelerates
• Transition from costly legacy to cost effective CE
infrastructure
• Demand from knowledgeable enterprises
• Faster rollout and increased availability of high
value CE business, access and mobile backhaul
services
• Increased interconnection of CE operators to
extend coverage of CE services (c) Anuradha Udunuwara

CE Transport Options
IEEE-based Transport
• Bridged networks (IEEE
802.1Q)
• PB Networks (IEEE
802.1ad)
• PBB networks (IEEE
802.1ah)
• PBB-TE networks (IEEE
802.1Qay)
MPLS-based
Transport
• MPLS VPWS
• MPLS VPLS
• MPLS-TP
Transparent
Transport
• SONET/SDH
• OTN
• xWDM

Native Ethernet in Metro Access
 How does one create the notion of a virtual circuit?
 VLAN tagging with point-to-point VLAN
 VLAN stacking
 Outer tag  service instance; Inner tag  individual customer
 802.1Q in 802.1Q (Q-in-Q) - IEEE 802.1ad
C-DA: Customer Destination MAC
C-SA: Customer Source MAC
S-TAG: IEEE 802.1ad S-VLAN Tag
C-TAG: IEEE 802.1q VLAN Tag
FCS: Customer Frame Check Sequence
C-DA C-TAGC-SA Client data FCSS-TAG
6bytes 6bytes 4bytes 4bytes 4bytes
T
y
p
e
2bytes

Customer
Network
Customer
Network
Customer
Network
87
Provider Bridge (PB) Architecture
CE: Customer Equipment
UNI: User-to-Network Interface
CES: Core Ethernet Switch/Bridge
UNI-B
CES
CES
CE-A
UNI-A
UNI-C
CE-C
Spanning tree
CE-B
CES

Limitations of PB Scalability
 Limited to 4096 (2 ^12) service instances
 Core switches must learn all MAC addresses
 Broadcast storms ensue due to learning
 MAC address tables explode!

Provider Backbone Bridging (PBB)
 Encapsulate customer MAC with provider MAC at edge
 Edge switch adds 24-bit service tag (I-SID), not VLAN tag
 Core switches need only learn edge switch MAC adds.
B-DA: IEEE 802.1ah Backbone Destination MAC
B-SA: IEEE 802.1ah Backbone Source MAC
B-TAG: IEEE 802.1ad B-VLAN Tag
I-TAG: IEEE 802.1ah Service Tag
B-DA B-TAGB-SA I-TAG C-DA C-TAGC-SA Client data B-FCS
6bytes 6bytes 6bytes6bytes4bytes 5bytes 4bytes 4bytes
T
y
p
e
2bytes

PBB Architecture
CPE BCPE A
CPE C
Provider backbone bridge
network (802.1ah)
CPE BCPE A
802.1ad
CPE B
CPE B
802.1q
CPE C
Provider bridge
network (802.1ad)
CPE D
CPE DCPE A
Provider bridge
network (802.1ad)
Provider bridge
network (802.1ad)
Provider bridge
network (802.1ad)

Benefits of PBB
 Scalability
 Addresses limitations of 4096 service instances
 Robustness
 Isolates provider network from broadcast storms
 Security
 Provider need switch frames only on provider addresses
 Simplicity
 Provider & customers can plan networks independently

Traffic Engineering in PBB
 Via Multiple Spanning Tree Protocol (MSTP)
 Maps a VLAN to ST or multiple VLANs to ST
 Enables use of links that would otherwise be idle in ST
 Eliminates wasted bandwidth … but …
 Too slow for protection switching
 Not suitable for complex mesh topologies
 Difficult to predict QoS

Source : http://www.technology-training.co.uk/carrierethernetandproviderbackbonebridging_33.php

Ethernet Frame formats
Source: https://sites.google.com/site/amitsciscozone/home/pbb/understanding-pbb
22 bytes
18 + 4 = 22 bytes
22 + 4 = 26 bytes
26 + 22 = 48 bytes
18 bytes

Challenges with an All-Ethernet Metro
Service
 Restriction on # of customers – 4096 VLANs!
 Service monitoring
 Scaling of Layer 2 backbone
 Service provisioning
 Carrying a VLAN is not a simple task!
 Inter-working with legacy deployments
 Need hybrid architectures …
Multiple L2 domains connected via IP/MPLS backbone

MPLS
 IP/MPLS is one of the ways to path engineer an
Ethernet frame
MPLS
Service
Transport

L2 & L3
 Traffic is switched
 Control signal is routed
Ex:-IP/MPLS
 Ethernet does not have a label. Therefore, we have
to create labels. One way is using MPLS.

Why MPLS for Ethernet Services (EoMPLS)?
 More Scalable (Free label Space)=>2^20
 Sub 50msec resiliency (MPLS Fast Reroute (FRR))
 Traffic Engineering (RSVP-TE)
 Hierarchical QoS (HQoS)
 Easy and simple to operate and maintain

Traffic
Service
Ethernet Service Switch
Physical Network
Ethernet over MPLS over Ethernet
MPLS
Ethernet
Physical
IP
Ethernet
MPLS or GRE
.1q
GE,10GE etc.
Outer label
Service label=VC label=inner label

Outer label 1
Ethernet
Inner label
Ethernet
Inner label
Outer label 2
Ethernet
Inner label
Outer label 3
Ethernet
Inner label
Outer label 4
EthernetEthernet
A E
D
C
B
Ethernet Ethernet
MPLS
LDP signaling session (TCP port 646)
RSVP-TE signaling
Ethernet frame: Get me to the other side

MPLS Transport Profile (MPLS-TP)
 Started as T-MPLS (Transport MPLS)
 MPLS-TP = IP/MPLS – IP

Why MPLS-TP?
 Similar “look and feel” to established SDH/SONET networks;
transport-like OAM
 Easier adoption by traditional transport network personnel
 Absence of control plane (less complexity)
 Simple provisioning of resilience (1:1, 1+1, and so on)
 Flexible: usable in both rings & limited connectivity
environments

Ethernet Over WDM Fiber
Future Proof
- Wavelength division multiplexing (WDM) enables multiple data
streams (wavelengths) per fiber link
- Add/Drop multiplexers provide new access points by splicing into the
WDM fiber link
Cost Effective
- Increase fiber access capacity and minimize installation of new fiber
links
- Small form pluggable transceivers, multiplexers
and media converters enable WDM wavelengths
with existing infrastructure equipment
Scalability
- Quickly implement new fiber access with
off-the-shelf hardware
- Wavelengths can deliver different network protocols
to mix Ethernet and TDM services over one fiber link
Central Office
Direct Fiber
Add/Drop
Multiplexer
Multiplexer
P2P WDM
Fiber Access
WDM Ring
Add/Drop
Multiplexer
Direct Fiber
NID

Ethernet Over SONET/SDHRapid service turn-up
 Leverages existing equipment and fiber plant
 Ubiquitous availability world wide
 Well understood provisioning and billing for off-net applications
 Ethernet enable on-net buildings
Highly resilient and secure service
 Sub-50ms resiliency
 Secure multi-tenant services
 Legacy TDM circuits supported natively
Flexible bandwidth options
 OC-3/STM1 up to OC-192/STM64 physical
 Sub-rate and Nx OC/STM are available with VCAT bonding
 Each channel carries one or more EVCs
Carrier Ethernet
Network
Available Service Bandwidth Standard Encapsulation
Technologies
Standard Circuit Bonding
Technologies
Ethernet over SONET/SDH 155 Mbps up to 1 Gbps) X.86, GFP VCAT, LAG
OC/STM
OC/STM
Add/Drop
Multiplexer
Add/Drop
Multiplexer
EoS Box
Multi-tenant EoS
Box

Factors Affecting CE Technology Selection
 Nature of operator’s business -- scope, size, customer base
 Business models -- pricing of services and VAS components
 Internal processes -- software, systems for a given technology
 Technical expertise available within the organization
 Legacy infrastructure of operator
 Geography, local conditions, technologies …
 Vendor support for given technology and equipment

Extending Carrier Ethernet into the First Mile
Ubiquity requires
multiple access
technology solutions
from the End-User
Subscriber to the CE
Network

Bonded
T1/E1
Ethernet
Ethernet Access for a Multi-Site Enterprise
MSO/ Cable
Ethernet User to Network Interface (UNI)
Ethernet Network Network Interface (NNI)
COAX
Direct Fiber
WDM
Fiber
Service
Provider 2
TDM
Ethernet
Ethernet Ethernet
Ethernet
Ethernet
Ethernet
Ethernet
Direct Fiber
100Mbps/1Gbps/10 Gbps
SONET/ SDH
PON
Fiber
Ethernet
Service
Provider 1
Ethernet
Ethernet
WiMax
Ethernet
Packet Wireless
DS3/E3

Reference
[1] MEF ( http://metroethernetforum.org )
[2] Ethernet Academy
(http://www.ethernetacademy.net/ )

About the Author
Eng. Anuradha Udunuwara is a Chartered Engineer by profession based in Sri Lanka. He has nearly a decade
industry experience in strategy, architecture, engineering, design, plan, implementation and maintenance of CSP
Networks using both packet-switched (PS) and Circuit-Switched (CS) technologies, along with legacy to NGN
migration. Eng. Anuradha is a well-known in the field of CSP industry, both locally and internationally.
Graduated from University of Peradeniya, Sri Lanka in 2001 with an honors in Electrical & Electronic Engineering,
Eng. Anuradha is a corporate member of the Institution of Engineers Sri Lanka, a professional member of British
Computer Society, a member of Institution of Electrical & Electronic Engineers, a member of Institution of
Engineering & Technology (formerly Institution of Electrical Engineers), a member of the Computer Society of Sri
Lanka, a life member of Sri Lanka Association for the Advancement of Science, a senior member of the Carrier
Ethernet Forum, a member of the Internet Society, a member of the Internet Strategy Forum, a member of the
Internet Strategy Forum Network, a member & a senior contributor of the Ethernet Academy, a member of the
NGN/IMS forum and a member of the Peradeniya Engineering Faculty Alumni Association. He is also an ITIL
foundation certified and the only MEF-CECP in the country.
In his spare time Anuradha enjoys spending time with his family, playing badminton, photography, reading and
travelling.
He can be reached at udunuwara@ieee.org

Carrier Ethernet

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