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Carrier Ethernet In-Depth:

End-to-end OAM & Network-to-Network Interfaces

Johannes WeingartDirector, Application & Solution ManagementADVA Optical Networkingjweingart@advaoptical.com

Enrique Hernandez-ValenciaAlcatel-Lucentenrique@alcatel-lucent.com

Presenters

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Carrier Ethernet: End-to-End OAM

A Key Element of the MEF’s Global Interconnect Strategy

Johannes Weingart

ADVA Optical Networking

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Topics

• The challenge of End-to-End OAM

• Solutions for fault detection and performance monitoring to support SLAs

• Latest developments in the MEF

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Challenges of CE for Service Providers

• Turn-up services quickly and efficiently – Be competitive; get revenues ASAP

• Reliability/Up-time (99.999%)

– Enable SLAs and keep revenues

• Quality

– Enhance customer satisfaction and retention

• Efficient operation

– Reduce OPEX costs; be competitive and profitable

• On/Off-Net services

– Increase effective footprint

– Access to national and global customer base

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OAM Drivers

• Carriers want visibility across other carriers’ networks, not into other carriers networks.

• Standard based, End-to-End OAM– Fault Detection, Verification & Isolation at every level– Customer notification of service degradation– PM and SLA verification with CoS

• Management Control Plane– Configuration Management– PM Collections

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Response to Challenges – Advanced Tools

• Point-to-Point Link OAM (802.3ah)• End-to-End Service Connectivity Fault OAM (802.1ag)• End-to-End Service Performance Monitoring (Y.1731)

• Two types of OAM– enhance automation– Link OAM

• P2P Connectivity monitoring and troubleshooting– Service OAM

• E2E Connectivity and Performance monitoring and troubleshooting

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Outline

• The challenge of End-to-End OAM

• Solutions for fault detection and performance monitoring to support SLAs

• Latest developments in the MEF

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OAM Layer Components

• Each layer supports OAM capabilities independently• OAMs interoperate • Component responsibilities are complementary

E2E Performance Monitoring

E2E Fault Monitoring“CFM”

P2P Link FaultManagement“EFM”

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Architecture Building Blocks

Point-to-Point EVCPoint-to-Point EVC

Carrier A

E-NNIUNI

Multi-point to Multi-point EVCMulti-point to Multi-point EVC

UNIUNI

Point-to-Point EVCPoint-to-Point EVC

UNI

UNI

UNI

Link OAM802.3ah

E2E Service OAM:Fault-802.1agPerform-Y.1731

Carrier B

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Link OAM (IEEE 802.3ah, Clause 57)

• Provides mechanisms useful for ‘monitoring link operation’, such as:

– Discovery & Link Monitoring– Remote Failure Indication– Remote Loopback Control

• Sometimes referred to as Ethernet OAM or more commonly EFM (Ethernet First Mile)

• Defines an optional OAM sub-layer:– Intended for point-to-point IEEE 802.3 links– Uses “Slow Protocol”1 frames called OAMPDUs

which are never forwarded by MAC clients– Standardized: IEEE 802.3ah, clause 57

(now in 802.3-2005)

OSI Model

Application

Presentation

Session

Transport

Network

LLC

OAM (Optional)

MAC

Physical

Dat

a Li

nk

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Service OAM - 802.1ag (aka “CFM”)

What is IEEE 802.1ag? – Provides for FAULT management of EVC-based service offerings.

802.1ag allows troubleshooting an end-to-end Ethernet Virtual Circuit (EVC) across multiple providers / vendors.

What is “CFM”? – CFM stands for “Connectivity Fault Management– Family of protocols that provides capabilities to detect, verify,

isolate and report end-to-end Ethernet connectivity faults– CFM and 802.1ag are used interchangeably

Standardized by IEEE (P802.1ag) in late 2007

– IEEE std. 802.1ag-2007

– 802.1ag is currently at revision 8.1 (CFM 8.1)

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Hierarchical OAM Domains

• A flat network is difficult to manage and define accountabilities• Hierarchical Maintenance Domains will bound OAM Flows & OAM responsibilities

Network OAM

Service OAM

Customer Domain

Provider Domain

Operator Domain

Operator Domain

Customer CustomerService Provider

UNI UNIE-NNI

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End to End Service OAM:Maintenance Associations

• Maintenance Association (MA) – Boundaries of an Administrator’s scope of monitoring part of the network

• Maintenance Domain (MD) – A level of monitoring within the hierarchy• Maintenance End Points (MEP) – End Points of the MA or MD• Maintenance Intermediate Points (MIP) – Intermediate Points within MA or MD

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ITU-T Y.1731: Fault and Performance Management

What is ITU-T Y.1731?

– A set of mechanisms for user-plane OAM functionality to provided fault and performance monitoring for point-to-point Ethernet networks.

– Technically aligned with IEEE 802.1ag

– Introduces performance measurements for SLA monitoring • Delay Measurement (DM)• Delay Variation Measurement (DVM)• Loss Measurement (LM)

– Expands on fault notification and isolation

• Automatic Protection Switching (APS)

• Ethernet Alarm Indication Signal function: ETH-AIS

• Ethernet Test Signal function: ETH-TEST

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E-LMI E-LMI

Service OAM; 802.1ag/Y.1731

• End-to-End per EVC OAM• Link Monitoring• Connectivity Fault Management

• Performance Monitoring and SLA metrics verification• MEF 16 E-LMI Service awareness; configuration and notification

UNI UNI

OAM – Putting it all Together

E-NNI

802.3ah 802.3ah 802.3ah 802.3ah 802.3ah 802.3ah 802.3ah 802.3ah802.3ah

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Outline

• The challenge of End-to-End OAM

• Solutions for fault detection and performance monitoring to support SLAs

• Latest developments in the MEF

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MEF 20: UNI Type 2 Implementation Agreement

• Allows provider equipment to provision, configure and distribute EVC information and attributes to customer equipment.

• Allows customer equipment to retrieve EVC status and configuration information from service provider equipment.

• Adds new set of functionalities to the ones defined in UNI Type 1– Link OAM– E-LMI– Service OAM– Protection– Enhanced UNI Attributes– L2CP Handling

Private Customer Network

End-user

Ethernet Virtual Connection

S S

End-user

Private Customer Network

Subscriber Subscriber

UNI UNI Metro

Ethernet Network

(MEN)

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MEF 21: Abstract Test Suites for UNI Type 2Part 1: Link OAM

• UNI Type 2 Certification Part 1– More complex to test than UNI Type 1– Includes Ethernet link and service OAM– UNI Type 2 service requires backwards

compatibility with UNI Type 1– Components of UNI type 2 test suite such

as Link OAM– Test one of the six elements of MEF 20– Work on other areas is in progress– Comprehensive: 272 Test Cases– Approved July 2008

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Service OAM:Performance and Fault Management

• Service OAM: Performance Management– Purpose: service performance monitoring– Planned to consist of extensions to the Y.1731/IEEE 802.1ag

procedures and protocols– Extensions are required to manage performance for multipoint

EVCs since Y.1731 only covers Point-to-Point EVCs

• Fault Management – Q.1731 and IEEE 802.1ag specify protocols and procedures for

fault management of Ethernet services. – The goal of this Implementation Agreement is to specify how to

use these two standards for the MEF standardized Ethernet services.

IMPORTANT NOTEThis information is preliminary

and is subject to change

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Abstract Test Suites

• UNI Type 2 Testing Parts 2, 3 – More complex to test than UNI Type 1– Includes Ethernet service OAM– UNI Type 2 service requires backwards compatibility with UNI Type 1– Components of UNI type 2 test suite such as Link OAM (completed as MEF

21) and E-LMI are work in progress• E-NNI Testing

– Tests the function, protection & recovery mechanisms of two interoperating MENs via their External Network to Network Interfaces. Uses similar constructs used in MEF 9 & MEF 14

– Abstract Test Suite is work in progress, dependson completion of E-NNI base specification

– Plans to include UNI services as far as they are mapped to E-NNI services

• Certification– UNI Type 2 and E-NNI Certification are

planned to be part of the MEF Certification Program

IMPORTANT NOTEThis information is preliminary

and is subject to change

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Carrier Ethernet: External Network-to-Network Interfaces

(E-NNI) A Key Element of the MEF’s Global Interconnect Strategy

Enrique Hernandez-Valencia

Alcatel-Lucent

January 2009

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Ethernet Service Demarcation Points

• UNI (User-to-Network Interface)– Demarcation point between

• Ethernet Service Provider/Access Network Provider and Subscriber– Ethernet Service (EVC) starting/ending point

• E-NNI (External Network-to-Network Interface)– Demarcation/peering point between:

• Ethernet Service Provider (ESP) and Access Network Provider• ESP and Transport (Long Haul) Network Provider

E-NNI E-NNIAccess Network Access Network

ProviderProvider

E-NNI Transport Transport

Network ProviderNetwork ProviderEthernet Service Ethernet Service

ProviderProvider

UNI UNI

EVCEVCSubscriber Subscriber

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What is the MEF E-NNI?

• External Network to Network Interface (E-NNI)

• A reference point where 2 Service Providers meet in support of specified MEF Services

• Technical functionally supported by equipment at the specified reference point in support of MEF Services (*E-NNI Functional Element)

UNIUNI UNIUNI

UNIUNI UNIUNI

UNIUNIE-NNIE-NNI

UNIUNI

Reference Point

EVC-1Carrier Anetwork

Carrier Bnetwork

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• Service– Type– MTU

• Endpoint– Service Mux– Tag ID/CoS

Preservation

• Link – Rate– L2CPs

Basic OAM Protection QoS

• Link OAM–IEEE 802.3ah

• Service OAM–IEEE 802.1ag & ITU-T Y.1731

• Link Protection– IEEE 802.3ad

(LAG)

• Service Protection– IEEE 802.1D

(STP/MSTP)

• BandwidthProfiles

– By EI – By EVC– By PCP– By DSCP

• Performance– Delay– Loss– Availability

E-NNI Attributes

Similar attribute structure as current MEF specifications

E-NNI Attributes

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E-NNI Phase I

In Scope:

• E-LINE and E-LAN services (but not E-TREE)– Inc. hair-pinning (e.g., frame may go in/out same PHY)

• Multiple Carrier Ethernet Networks– Inc. multiple E-NNIs or links between two Carrier Ethernet Networks

• E-NNI link protection (but not End-to-End service protection)– Customers & SP must provide loop-free connectivity

• End-to-End OAM and QoS– Inc. traffic “coloring” via IEEE PCPs or IETF DSCPs

• Service Frame delineation via IEEE 802.1– No S-Tag or single S-Tag

Approved MEF Specification

• Available 2H 2009

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E-NNI Constructs: Component EVC (CEVC)

• MP-to-MP EVC1 associates UNI4, UNI5 and UNI6

• EVC1 decomposed into 3 CEVCs

– CEVC A1 within Operator A’s network

– CEVC B1 within Operator B’s network

– CEVC C1 within Operator C’s network

UNI4

Operator A

UNI6

E-NNI

C1

Operator CE-NNI

A1

UNI5

EVC1

B1

Operator B

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Digging Tunnels

• Terminating Tunnel introduces the Termination End Points on a third party network

– Connects a Remote UNI on Network Operator to a Virtual UNI (V-UNI) from the Service Provider

– The Terminating Tunnel passes all Subscriber traffic as is to

• Generalization of ESC* may introduce additional types of tunnels

* ESC: Ethernet Services Constructs (Ongoing Project)

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UNI

EVC2

EVC1

Operator 3

E-NNI Constructs: Tunnels, VUNIs and RUNIs

• Tunnels– Terminating Tunnels (associates a VUNI and an RUNI)

• VUNI (Virtual UNI)– Logical interface at endpoint of E-NNI side of Terminating Tunnel– Maps CEVC(s) to its Terminating Tunnel

• RUNI (Remote UNI)– Logical interface at end point of UNI side of the Terminating Tunnel

VUNI

Terminating Tunnel

E-NNI

UNI

Operator 2

RUNI

EVC1

EVC2

EVC3

E-NNI

UNI

UNI

Operator 1

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E-NNI Constructs: Putting it all together

E-NNI UNI2

• Access Network Provider – Provides CEVC1 connection between Subscriber UNI1 (RUNI) and E-NNI1 with

Transport Network Provider

• Transport Network Provider– Provides CEVC2 connection between E-NNI1 and E-NNI2 with Ethernet

Service Provider

• Ethernet Service Provider– Provides connection to E-NNI2 with Transport Network Provider

– Provides End-to-End Ethernet Service to Subscriber• Connects VUNI to Terminating Tunnel

• Provides EVC between UNI1 and UNI2

UNI1 Transport Transport

Network ProviderNetwork Provider

Ethernet Service Ethernet Service ProviderProvider

Term.TunnelTerm.TunnelTerminating TunnelTerminating Tunnel

EVC

Access Network Access Network

ProviderProvider

RUNI E-NNI1 and ENNI2

E-NNI1 E-NNI2

SubscriberCEVC1 CEVC2Subscriber

VUNI

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