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1
Carrier Ethernet In-Depth:
End-to-end OAM & Network-to-Network Interfaces
Johannes WeingartDirector, Application & Solution ManagementADVA Optical [email protected]
Enrique [email protected]
Presenters
2
Carrier Ethernet: End-to-End OAM
A Key Element of the MEF’s Global Interconnect Strategy
Johannes Weingart
ADVA Optical Networking
3
Topics
• The challenge of End-to-End OAM
• Solutions for fault detection and performance monitoring to support SLAs
• Latest developments in the MEF
4
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
5
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
6
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
7
Outline
• The challenge of End-to-End OAM
• Solutions for fault detection and performance monitoring to support SLAs
• Latest developments in the MEF
8
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”
9
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
10
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
11
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)
12
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
13
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
14
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
15
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
16
Outline
• The challenge of End-to-End OAM
• Solutions for fault detection and performance monitoring to support SLAs
• Latest developments in the MEF
17
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)
18
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
19
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
20
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
22
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
23
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
24
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
25
• 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
26
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
27
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
28
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)
29
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
30
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
31
For more informationVisit: www.metroethernetforum.org
Thank You