Download Link OAM (IEEE 802.3ah)

Technology Brief
Ethernet OAM
OAM: Operations, Administration, Maintenance
Feb 2010,
ESPD
Agenda

General Challenges for Service Providers

Drivers for Ethernet OAM

OAM Standards

OAM Domain Architecture

Link OAM (IEEE 802.3ah)

Service OAM (IEEE 802.1ag)

ITU-T Y.1731

OAM Configuration Guide

Summary
General Challenges for Service Providers

Must be able to provide services quickly and efficiently.

Must be able to provide reliability and up-time (99.999%)
that fulfills Service-Level Agreement (SLA).

Must be able to enhance customer satisfaction and retention.

Must be able to run the operation efficiently and still be able
to reduce overall costs.

Must be able to maintain overall competitiveness and also
generate revenue.
General Challenges for Service Providers

What makes an Ethernet Service Provider attractive?
Source: Heavy reading 2008
Agenda

General Challenges for Service Providers

Drivers for Ethernet OAM

OAM Standards

OAM Domain Architecture

Link OAM (IEEE 802.3ah)

Service OAM (IEEE 802.1ag)

ITU-T Y.1731

OAM Configuration Guide

Summary
Drivers for Ethernet OAM
1. REDUCE COST!!
Example: A truck roll is required each time a network
event happens. The cost varies widely, but is in the
USD $200~400 range per event.
Ethernet OAM can drastically reduce the operational expenditure
while providing equivalent or better maintenance tools than
legacy devices.
Opex
Capex
Legacy
services
Best effort
Ethernet
Carrier
Ethernet
Drivers for Ethernet OAM (cont.)
2. Service providers want visibility across other providers’
networks, but not into other providers’ networks.
3. Service providers need standards-based, End-to-End OAM for:






Automated configuration; fast service turn up

Network resilience and fast recovery
End-to-end service control
Hop-by-hop fault management
Preventative maintenance and troubleshooting
Customer notification of service degradation
Performance Monitoring (PM) and Service-Level Agreement (SLA)
verification with CoS and QoS
Drivers for Ethernet OAM (cont.)
4.
Uphold Service-Level Agreement (SLA)
- Agreement between Service Provider and customer
- Defines reliable and predictable communications networks, with
metrics and operational methods similar to what they experience
today

Critical for Carrier Ethernet
•

SLA already exists in Frame Relay, Private Line and ATM
Customers want SLAs and Proof of Compliance
•

Management and Reporting are key elements
Defines Responsibility
•
Need to sort out which carrier is at fault
Agenda

General Challenges for Service Providers

Drivers for Ethernet OAM

OAM Standards

OAM Domain Architecture

Link OAM (IEEE 802.3ah)

Service OAM (IEEE 802.1ag)

ITU-T Y.1731

OAM Configuration Guide

Summary
OAM Standards
Pre-Carrier Ethernet
IP
Ethernet
SONET
Physical
Modern Carrier Ethernet
“Global Interconnect”
IP
Ethernet
Physical
Best Effort
Performance SLAs
Point to Point
E-LAN, E-Line, E-Tree
Limited resiliency
50ms recovery
Metro-only
Global Interconnect
Transport only OAM
End-to-end Service OAM
Asynchronous
Sync-E, IEEE 1588
OAM Standards
Standards Body
Ethernet OAM
IEEE
• 802.3ah – Ethernet in the First Mile
• 802.1ag – Connectivity Fault Management
• 802.1aj – Two Port MAC Relay
MEF
• MEF 7 – EMS-NMS Info Model
ITU
• Y.1730 – Ethernet OAM Req
IETF
• RFC-2544 – Benchmarking Method for Ntwk Interconnect Dev
TMF
• TMF814 – EMS to NMS Model (Corba)
•
•
•
•
•
•
•
•
•
•
MEF 13 – UNI-Type 1
MEF 15 – NE Management Req
MEF 17 – OAM Req & Framework
MEF 16/20 – Ethernet Local Mgmt Interface/UNI-Type 2
Service OAM – Performance Monitoring
NID Specifications
Y.1731 – OAM Mechanisms
G.8031 – Ethernet Protection
Y.17ethqos – QoS
Y.ethperf – Performance
• RFC-2819 – Remote Monitoring (RMON Etherstats)
• TMF854 – EMS to NMS (Web services - MTOSI)
OAM Standards -
User to Network Interface (UNI)
• Defines an Ethernet service demarcation
point between customer (subscriber) and
service provider
• Defines service personality – service
attributes, traffic classification, bandwidth
profiles, tagging, etc.
• 3 types defined: Type 1, Type 2, Type 3
CE
customer
responsibility
Carrier
Ethernet
Network
UNI
Service provider
responsibility
CE: Customer Equipment
UNI: User Network Interface
OAM Standards –
UNI Types
 UNI type 1 (MEF 13)
• Manually configured UNI
• Defines service personality - Traffic classification, bandwidth profile(s), etc
• UNI Type 1.1 and 1.2 are defined
 Type 1.1 : Non-multiplexed UNI for Services like EPL*
 Type 1.2 : Multiplexed UNI for Services like EVPL*
• Certification test suite in MEF 19
 UNI type 2 (MEF 20)
• Backward compatibility with UNI Type 1
• Adds additional management capabilities including Ethernet Local
Management Interface (E-LMI) from MEF-16
• Provides fault indication and automated configuration/provisioning of UNI-C
• Certification test suite in MEF 21 & 24 (and others)
 UNI type 3 (future)
• Negotiated configuration/provisioning between UNI-C and UNI-N
OAM Standards –
UNI Types (cont.)
Functional Elements of the UNI
• MEF-11 defines a split in the demarcation function between
customer and service provider:
• UNI-C: Executes the processes of the customer side
• UNI-N: Executes the processes of the network side
UNI-C
CE
Carrier
Ethernet
Network
UNI-N
customer
responsibility
UNI
Service provider
responsibility
CE: Customer Equipment
UNI: User Network Interface
OAM Standards -
Network to Network Interface (NNI)
UNI
UNI
Carrier A
network
Ethernet
Virtual
Connection
UNI
E-NNI
Carrier B
network
UNI
Reference
Point
 External Network to Network Interface (E-NNI)
• A reference point where 2 Service Providers meet in support of specified MEF
Services
 Supports
• Multiple Carrier Ethernet networks and services, management, QoS , etc.
• Supports simple interconnect and tunneling
 Impact on the Industry
• Creates ubiquitous service level network for large and mid-size businesses
• Generates new worldwide business opportunities for service providers at
lower cost
• Brings new product and revenue opportunities for vendors
OAM Standards
Customer
Site
Service Provider 1
Service Provider 2
E-NNI
UNI
Customer
Site
UNI
CE
CE
Access Link OAM
Link
OAM
Access Link OAM
MEF NID*
IEEE 802.3ah
MEF NID*
IEEE 802.1ag
Connectivity Fault Mgmt OAM
Service
OAM
Service Layer OAM (UNI to UNI)
ITU Y.1731
OAM Standards
OAM Layer Components
*
**

Each layer supports OAM capabilities independently

OAMs interoperate

Component responsibilities are complementary
*: E2E = End-to-End
**: P2P = Point-to-Point
OAM Standards – Link OAM
 IEEE 802.3ah - Ethernet in the first mile (EFM)
• First OAM standard completed (2004)
• Supports:





Remote Loopback
Remote failure indication (dying gasp, link fault and critical event)
Link monitoring
Loopback Control
Discovery
 Focused on point-to-point Ethernet link OAM
• Does not propagate beyond a single link or hop
• Maintenance OAM, not service
 Ethernet OAM shares bandwidth with data payload
• Utilizes a “slow” protocol limited to 10 packets per second
• OAMPDUs identified by MAC address and Ethernet Length/Type/subtype field
• Uses a protocol sub layer between physical and Data link layers
OAM Standards – Service OAM
 Includes 802.1ag and Y.1731
 Uses synthetic traffic to measure end to end performance
of service
 Supports multiple layers of OAM and maintenance regions
OAM Standards – Service OAM
 IEEE 802.1ag – Connectivity Fault Management (CFM)


CFM standard is the foundation for Services OAM
Basic connectivity checking and troubleshooting across any domain,
and across multiple domains at the same time
 Partitions network into hierarchical OAM regions fault management
 Supports up to 8 hierarchical levels of monitoring

Mechanisms include
 Continuity Check (CC)
 Loopback
 Linktrace
 Also provides the ability to monitor at specific service levels
(including customer, service provider, operator, section) and support for
maintenance domains.
OAM Standards – Service OAM
 ITU Y.1731:
 Builds on 802.1ag and adds:

Performance Monitoring
 Delay Measurement (DM)



AIS & RDI



Delay Variation Measurement (DVM)
Loss Measurement (LM)
Alarm Indication Signal (AIS)
Remote Defect Indication (RDI)
Test pattern & Test mode
 But no test methodology or standards test suite
Agenda

General Challenges for Service Providers

Drivers for Ethernet OAM

OAM Standards

OAM Domain Architecture

Link OAM (IEEE 802.3ah)

Service OAM (IEEE 802.1ag)

ITU-T Y.1731

OAM Configuration Guide

Summary
OAM Domain Architecture

A flat network is difficult to manage and define accountabilities

Green, Blue and Orange represent different levels of domains

Hierarchical Maintenance Domains will bind OAM Flows & OAM
responsibilities
OAM Domain Architecture

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
Agenda

General Challenges for Service Providers

Drivers for Ethernet OAM

OAM Standards

OAM Domain Architecture

Link OAM (IEEE 802.3ah)

Service OAM (IEEE 802.1ag)

ITU-T Y.1731

OAM Configuration Guide

Summary
Link OAM (IEEE 802.3ah)
 Provides mechanisms useful for ‘monitoring link
operation’, such as:
• Discovery & Link Monitoring
• Remote Failure Indication
• Remote Loopback Control
• Improve Fault Isolation


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” frames called OAMPDUs
which are never forwarded by MAC clients
• Standardized: IEEE 802.3ah, clause 57
(now in 802.3-2005)
Link OAM (IEEE 802.3ah)
 OAM Sub-layer:
•
OAM Client
 Configures OAM sublayer
•
through Control
 Processes received PDUs
 Transmits PDUs
Control
 Provides interface with OAM
•
client entity
Parser
 Inspects received frames,
•
sends PDUs to control
 Sends Non-PDUs to upper layer or
Multiplexer
Multiplexer
 Multiplexes PDUs and non-PDUs
Link OAM (IEEE 802.3ah)
 Link OAM Does NOT provide capability for:
 Station Management
 Protection Switching*
 Provisioning**
No set functions
 Bandwidth Allocation

 Speed / Duplex Negotiation
 End-to-end OAM Communication

802.3ah scope restricted to single links
Link OAM (IEEE 802.3ah) - OAMPDU
 OAMPDU:
• Link OAM communicates using OAMPDUs
• OAMPDUs are not forwarded by bridges: restricted to single link
 Two ends of a single link are referred to as
Data Terminal Equipments (DTE) in 802.3
• Communication beyond a single link is left to higher layers
Link OAM (IEEE 802.3ah) - OAMPDU
 OAMPDU: Size / Rate
• Must be standard frame length
 64-1518 bytes
 Maximum PDU size determined during
Discovery process
 Subtype = 0x03 [OAM]
• Must be untagged
• Maximum of 10 OAMPDUs per second
 Slow Protocol frames
Link OAM (IEEE 802.3ah) - DULD
 OAM Discovery
• Allows local DTE to detect OAM on remote DTE
• Once OAM support is detected, both ends of the link exchange state and
configuration information
 PDU Size, Loopback support, etc…
• If both DTEs are satisfied with settings, OAM is enabled on link
 D-Link Unidirectional Link Detection (DULD)
• D-Link standard implementation for detecting unidirectional link
 Utilizes 802.3ah Discovery handshake process
 Uses the Organizational Specific TLV field in OAMPDU
• Similar in function and purpose to Cisco’s UDLD
Link OAM (IEEE 802.3ah) - Flags
 OAMPDU format – Flags
Link OAM (IEEE 802.3ah) - Flags
 OAMPDU format – Flag Bits
• (15~7) Reserved
 Reserved bits shall be set to zero when sending an OAMPDU and ignored on reception
• (6) Remote Stable
• (5) Remote Evaluating
 Used to indicate status of the remote DTE
• (4) Local Stable
• (3) Local Evaluating
 Used to indicate status of the local DTE Discovery process
Critical Event Flags
• (2) Critical Event
 An unspecified critical event has occurred
• (1) Dying Gasp
 Signal remote device that an unrecoverable local fault has occurred
• (0) Link Fault

Signal remote device that receive path is broken
Link OAM (IEEE 802.3ah) - Code
 OAMPDU format – Code (1 Byte)
•
Information (0x00)
 Used to send OAM state information to the remote DTE
• Event Notification (0x01)
 Alerts remote DTE of link events
• Variable Request & Response (0x02 & 0x03)
 Requests & Returns one or more specific MIB variables
• Loopback Control (0x04)
 Enables/disables OAM remote loopback
 Controls the remote DTE’s OAM remote loopback
state
Organization Specific (0xFE)
 Reserved for Organization Specific Extensions
 Distinguished by OUI
Link OAM (IEEE 802.3ah) – Loopback
 802.3ah OAM – Loopback
Remote Loopback mechanism:
• Loopback Control OAMPDU is used to control the remote DTE
 Use 0x01 Enable to start Loopback, 0x02 Disable to exit Loopback
• Traffic sent from local DTE is looped back by remote DTE except for
Pause and OAMPDU
Link OAM (IEEE 802.3ah) – Loopback
 802.3ah OAM – Remote Loopback
Provides:
• Fault localization and link performance testing
 Statistics from both the local and remote DTE can be
queried and compared at any time
Additional information about the health of the link
 Can be used to determine which frames are being dropped
due to link errors
Link OAM (IEEE 802.3ah) – Loopback
 802.3ah OAM – Starting Remote Loopback
Link OAM (IEEE 802.3ah) – Loopback
 802.3ah OAM – Exiting Remote Loopback
Agenda

General Challenges for Service Providers

Drivers for Ethernet OAM

OAM Standards

OAM Domain Architecture

Link OAM (IEEE 802.3ah)

Service OAM (IEEE 802.1ag)

ITU-T Y.1731

OAM Configuration Guide

Summary
Service OAM (IEEE 802.1ag)
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)
Service OAM (IEEE 802.1ag)
 Refresh on the hierarchical OAM Architecture
 Each MD level contains different MEP
• MEP in a MD may be MIP in a higher-level MD
 802.1ag supports up to 8 hierarchical levels
Service OAM (IEEE 802.1ag)
 Comprised of 3 protocols that provide Fault Mgmt in Ethernet networks:
• Continuity Check Message
– Provides fault detection and notification.
 Uni-directional "heartbeat" messages issued periodically by MEPs inward in an MD
 Allow MEPs to detect loss of service connectivity and can be integrated to provide fault
notification.
 Allow MEP to discover other MEP within a domain, and allow MIP to discover MEPs
• Linktrace Message/Reply
– Provides fault isolation.
 Transmitted by a MEP on demand to track the path (hop-by-hop) to a destination
Maintenance Point (MP)
 Allow the transmitting node to discover vital connectivity data (hops) in the path.
This is quite similar to Trace Route functionality in IP.
• Loopback Message/Reply
– Provides fault verification.
 Transmitted by a MEP on demand to verify connectivity to a particular MP.
 Indicates whether the destination is reachable or not
 Does not allow hop-by-hop discovery of the path (unlike Linktrace)
 Similar to Ping functionality in IP
Service OAM (IEEE 802.1ag) - CCM
 Connectivity Check Messages (CCMs) are periodic multicast
messages used for detecting loss of continuity within an MA
• Each MEP transmits CCMs to all other MEPs in the MA at a configurable
interval
 3.33ms: default transmission period for protection switching
 100ms: default transmission period for performance monitoring
 1s: default transmission period for fault management
• Upon loss of 3 consecutive CCMs, a loss of continuity defect is declared
UNI
UNI
Carrier IP
Network
EoX
MEP (Probe)
CCM
data
Provider
Edge
EoX
Provider
Edge
MEP (Reflector)
Service OAM (IEEE 802.1ag) – Link Trace
 Link Trace determines the path from a MEP to a MAC address
UNI
Metro
Aggregation
Network
Access
Network
MEP
IP/MPLS Core
Network
MIP
MIP
UNI
Metro
Aggregation
Network
MIP
Link trace Reply
Link Trace is similar to IP’s Traceroute
Access
Network
MIP
MEP
Service OAM (IEEE 802.1ag) – Loopback
What is Loopback good for?
• MEP can send a Loopback to any MEP or MIP in the service
• Loopback follows the unicast path, not the multicast path
• Sending loopbacks to successive MIPs can determine the location of the fault
UNI
Metro
Aggregation
Network
Access
Network
MEP
IP/MPLS Core
Network
MIP
MIP
UNI
Metro
Aggregation
Network
MIP
Loopback is similar to IP’s Ping
Access
Network
MIP
MEP
Service OAM (IEEE 802.1ag)
 802.1ag CFM Protocol
CCMs and LTMs are carried in multicast frames with a
Dest. MAC chosen according to the MD level
Agenda

General Challenges for Service Providers

Drivers for Ethernet OAM

OAM Standards

OAM Domain Architecture

Link OAM (IEEE 802.3ah)

Service OAM (IEEE 802.1ag)

ITU-T Y.1731

OAM Configuration Guide

Summary
ITU-T Y.1731
 What is ITU-T Y.1731?
• A set of mechanisms for user-plane OAM functionality to provide
fault and performance monitoring for point-to-point Ethernet
networks.
• Technically aligned with IEEE 802.1ag
• Introduces performance measurements for SLA monitoring
 Frame Delay Measurement (DM)
 Frame Delay Variation Measurement (DVM)
 Frame Loss Measurement (LM)
• Expands on fault notification, isolation & diagnostics
 Ethernet Alarm Indication Signal function: ETH-AIS
 Ethernet Locked Signal: ETH-LCK
 Ethernet Test Signal function: ETH-TEST
ITU-T Y.1731 – ETH-AIS
 Alarm Indication Signal
• ETH-AIS is used to suppress alarms following detection of defect conditions.
 When a MEP detects a connectivity fault (mostly through CCM), it will multicast AIS
in the direction away from the detected failure at the immediate client MA level
 MIP will propagate to the MEP in their own MA level
CCM
AIS
ITU-T Y.1731 – ETH-AIS
 What is AIS good for?
• Receiving MEPs may:
 Catalogue AIS and wait to see whether their own CCs report a failure
 If Spanning Tree repairs error, none needs to be generated
 Delay the propagation of AIS
 Gives Spanning Tree time to correct the problem
 Propagate the failure reported by AIS
 Assuming there is no Spanning Tree to correct the problem
Agenda

General Challenges for Service Providers

Drivers for Ethernet OAM

OAM Standards

OAM Domain Architecture

Link OAM (IEEE 802.3ah)

Service OAM (IEEE 802.1ag)

ITU-T Y.1731

OAM Configuration Guide

Summary
Network Topology – 802.3ah OAM
DES-3528
Service Provider
Network
OAMPDU
OAMPDU
DES-3200 (1)
DES-3200 (2)
PE
PE
 The Goals:
1.Enable the Ethernet OAM & monitor the remote client status
2.Enable OAM Remote Loopback mechanism
3.Enable the Critical Event notification
Link OAM Configuration
DES-3528
config ethernet_oam ports 1-2 state enable
config ethernet_oam ports 1-2 mode active
DES-3200 (1 & 2)
config ethernet_oam ports 1 state enable
config ethernet_oam ports 1 mode passive
Pull and plug Port 1 of DES-3200 and check the OAM status on Port 1 of
DES-3200 or Port 1 of DES-3538
>show ethernet_oam ports 1-2 status
Link OAM Packet Capture
OAMPDU which uses Slow Protocol MAC “01-80-C2-00-00-02”
Link OAM Remote Loopback
Use DES-3528 to send Remote Loopback to DES-3200
DES-3528
Sniffer
DES-3200
PE
Service Provider
Network
Remote Loopback Configurations
DES-3528
config vlan vlanid 1 delete 3
create vlan 3 tag 3
config vlan vlanid 3 add untagged 3
config mirror port 3 add source ports 1 both
enable mirror
config
config
config
config
ipif System ipaddress 10.90.90.90/8
ethernet_oam ports 1 mode active
ethernet_oam ports 1 state enable
ethernet_oam ports 1 received_remote_loopback process
DES-3200
config ipif System ipaddress 10.90.90.91/8
config ethernet_oam ports 1 mode active
config ethernet_oam ports 1 state enable
config ethernet_oam ports 1 received_remote_loopback process
Issue the following command to Start/Stop the Remote_Loopback on DES-3528
>config ethernet_oam ports 1 remote_loop start
>config ethernet_oam ports 1 remote_loop stop
Remote Loopback OAM Status
Show Ethernet_OAM Statistics by the following commands
Remote_loopback packet (Start)
Remote_loopback packet (Stop)
Remote Loopback OAM Status
Check DES-3528 Ethernet Remote Loopback Port’s Status
Check DES-3200 Ethernet Remote Loopback Port’s Status
Remote Loopback Verification
Steps:
1. Start the Remote loopback on DES-3528
>config ethernet_oam ports 1 remote_loop start
2. Issue a ‘ping’ packet from DES-3528’s console to DES-3200
> ping 10.90.90.91
3. From the sniff PC, you will see 2 ICMP packets captured as below.
a.) The first ICMP packet is from DES-3528 to DES-3200
b.) the second ICMP packet is returned by DES-3200. The original
packet’s format will be kept without changed.
The first packet is from DES-3528
The second packet is looped back by DES-3200
Enable Link OAM Critical Event
DES-3528
Service Provider
Network
OAMPDU
OAMPDU
DES-3200 (1)
DES-3200 (2)
PE
PE
Critical Event Configuration
DES-3528
config ethernet_oam ports 1-2 state enable
config ethernet_oam ports 1-2 mode active
config ethernet_oam ports 1-2 critical_link_event critical_event notify_state enable
DES-3200 (1)
config ethernet_oam ports 1 state enable
config ethernet_oam ports 1 mode active
config ethernet_oam ports 1 critical_link_event critical_event notify_state enable
Issue the following command to disaply the event_log
>show ethernet_oam ports 1 event log
Critical Event Packet Capture
Network Topology – 802.1ag OAM
MD1
DGS-3700 (1)
DGS-3700 (2)
MD2
DES-3200 (1)
DES-3200 (2)
P1
P1
P2
MEP/ MIP
P2
P1
MEP/ MIP
MEP (Probe)
MEP2
P1
MEP (Reflector)
MEP2
MIP
MIP
MIP
MIP
MEP1
MEP1
 The Goals:
1. Create 2 Maintenance Domains, MD1 & MD2. MD1 & MD2’s ports are overlapping.
2. MD1 includes 2 MEPs & 4 MIPs.
3. MD2 includes 2 MEPs.
4. Make sure the CCM(Continuity Check Message) transmission between MEPs
5. Use a Linktrace on demand to track the path (hop-by-hop) to a destination MP
6. Use a Loopback message verify connectivity to a particular MP
CFM OAM Configuration (1)
DES-3200 (1)
enable cfm
config cfm ports 1 state enable
create cfm md md1 level 1
create cfm ma ma1 md md1
config cfm ma ma1 md md1 vlanid 1 mip auto sender_id defer ccm_interval 10sec
config cfm ma ma1 md md1 mepid_list add 5-6
create cfm mep mep1 mepid 5 md md1 ma ma1 direction outward port 1
config cfm mep mepname mep1 pdu_priority 7
config cfm mep mepname mep1 state enable
config cfm mep mepname mep1 ccm enable
DGS-3700 (1)
enable cfm
config cfm ports 1-2 state enable
create cfm md md1 level 1
create cfm ma ma1 md md1
config cfm ma ma1 md md1 vlanid 1 mip auto sender_id defer ccm_interval 10sec
config cfm ma ma1 md md1 mepid_list add 5-6
create vlan v2 tag 2
config vlan v2 add tagged 2
create cfm md md2 level 2
create cfm ma ma2 md md2
config cfm ma ma2 md md2 vlanid 2 mip auto sender_id defer ccm_interval 10sec
config cfm ma ma2 md md2 mepid_list add 7-8
create cfm mep mep2 mepid 7 md md2 ma ma2 direction outward port 2
config cfm mep mepname mep2 pdu_priority 7
config cfm mep mepname mep2 state enable
config cfm mep mepname mep2 ccm enable
CFM OAM Configuration (2)
DES-3200 (2)
enable cfm
config cfm ports 1 state enable
create cfm md md1 level 1
create cfm ma ma1 md md1
config cfm ma ma1 md md1 vlanid 1 mip auto sender_id defer ccm_interval 10sec
config cfm ma ma1 md md1 mepid_list add 5-6
create cfm mep mep1 mepid 6 md md1 ma ma1 direction outward port 1
config cfm mep mepname mep1 pdu_priority 7
config cfm mep mepname mep1 state enable
config cfm mep mepname mep1 ccm enable
DGS-3700 (2)
enable cfm
config cfm ports 1-2 state enable
create cfm md md1 level 1
create cfm ma ma1 md md1
config cfm ma ma1 md md1 vlanid 1 mip auto sender_id defer ccm_interval 10sec
config cfm ma ma1 md md1 mepid_list add 5-6
create vlan v2 tag 2
config vlan v2 add tagged 1
create cfm md md2 level 2
create cfm ma ma2 md md2
config cfm ma ma2 md md2 vlanid 2 mip auto sender_id defer ccm_interval 10sec
config cfm ma ma2 md md2 mepid_list add 7-8
create cfm mep mep2 mepid 8 md md2 ma ma2 direction outward port 1
config cfm mep mepname mep2 pdu_priority 7
config cfm mep mepname mep2 state enable
config cfm mep mepname mep2 ccm enable
MEP/MIP MAC Addresses
1. Display MEP MAC address:
[Usage]: show cfm ports <portlist>
Example: >show cfm ports 1
2. Disaplay MIP MAC address:
[Usage]: show cfm {[md <string 22> {ma <string 22>
{mepid <int 1-8191>}} | mepname <string 32>]}
Example: >show cfm md md1 ma ma1
DGS-3700 (2)
DGS-3700 (1)
Carrier IP Network
DES-3200 (1)
DES-3200 (2)
P1
P1
P2
MEP/ MIP
MEP (Probe)
MIP1 MAC:
00-22-B0-7A-66-81
MEP1 MAC:
00-80-C8-35-52-02
P2
P1
P1
MEP/ MIP
MEP (Reflector)
MIP1 MAC:
00-1E-58-6E-97-82
MEP2 MAC:
00-22-B0-7A-66-82
MEP2 MAC:
00-1E-58-6E-97-81
MIP1 MAC:
00-22-B0-7A-66-82
MIP1 MAC:
00-1E-58-6E-97-81
MEP1 MAC:
00-26-5A-2A-E0-11
Continuity Check Message (CCM)
Sniff the MEP1 connection to make sure the CCM is transmitted
CFM OAM Linktrace
Perform Linktrace in-between MEPs
1. Use Linktrace to track the path (hop-by-hop) to a destination Maintenance
End Point
2. Display the MIPs of the Linktrace path
MIPs
Linktrace Packet Capture
Linktrace Message (LTM)
Linktrace Reply (LTR)
CFM OAM Loopback
Loopback Message(LBM)
Loopback Reply(LBR)
Agenda

General Challenges for Service Providers

Drivers for Ethernet OAM

OAM Standards

OAM Domain Architecture

Link OAM (IEEE 802.3ah)

Service OAM (IEEE 802.1ag)

ITU-T Y.1731

OAM Configuration Guide

Summary
Summary
 Establishing end-to-end OAM is a key part of delivering highperformance, carrier-grade Ethernet services.
 Link OAM monitors link discovery, operation and health
 CFM OAM provides operational efficiency, rapid per-service fault
identification, verification and isolation for high availability services
over multi-operator networks.
 OAM Performance Monitoring provides means to monitor and report
key SLA and service usage metrics.
Summary: OAM Comparison
802.3ah Link OAM
802.1ag CFM OAM
Operates on physical link only.
Cannot pass through a bridge
May be per-service or per-wire.
Passes “end-to-end” through
bridges
Discovery, Variable request &
response, Event Notification,
Information, Remote Loopback
Connectivity Verification,
Linktrace, Loopback
Single instance per physical link
Multiple instances operating at
multiple levels simultaneously
Created by one committee
Joint effort by IEEE 802.1, ITUT
Approved in 2004 and included
in the IEEE 802.3 standard in
2005
Amendment to IEEE 802.1Q2005 and approved in 2007
Thank you!
Reference
 MEF_OAM_tutorial_Toronto by MEF (Metro Ethernet Forum)
 EFM OAM Tutorial – World Wide Packets, July, 2003