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draft-sajassi-mohan-l2vpn-vpls-fm-00.txt draft-mohan-sajassi-l2vpn-vpls-pm-00.txt. Dinesh Mohan (Nortel) mohand@nortelnetworks.com. Ali Sajassi (Cisco) sajassi@cisco.com. IETF-59, Seoul March 3, 2004. Contributors & Acknowledgements. Other contributors Shahram Davari (PMC Sierra) - PowerPoint PPT Presentation
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draft-sajassi-mohan-l2vpn-vpls-fm-00.txtdraft-mohan-sajassi-l2vpn-vpls-pm-00.txt
Dinesh Mohan (Nortel) mohand@nortelnetworks.com
IETF-59, Seoul March 3, 2004
Ali Sajassi (Cisco) sajassi@cisco.com
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Contributors & Acknowledgements
• Other contributors– Shahram Davari (PMC Sierra)– Nortel & Cisco colleagues
• Other Standards Participants– ITU-T (Q.3/13)– MEF– IEEE (802.1 & 802.3)
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Scope of Current Work
EMS
NENE NE
EMS
NENE NE
NMSEnvironment
EMS-NMS Interface
EMS-NE Interface
Supplier Subnetwork Supplier Subnetwork
• Within L2VPN Charter– “L2VPN-specific OAM extensions--extensions to existing OAM solutions for
VPLS, VPWS, and IP-only L2VPNs”– Fault and Performance Management within FCAPS
• Alignment with work in other bodies– ITU-T Q.3/13, IEEE 802.1, MEF
• Focus on OAM Procedures across NEs
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General Concepts – L2 OAM Framework
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VPLS OAM Layering – Service Layer
CE U-PE U-PEN-PEN-PE CEB B P P P PDevice View
Example Scenario with Single Service Provider Network
Ethernet Layer
Eth Access MPLS Core MPLS Access
Customer CustomerService Provider
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OAM Domain – Service/Network
Eth Access MPLS Core MPLS Access
Customer CustomerService Provider
Customer Domain
Provider Domain
Operator Domain Operator Domain
Operator Domain
• Domains necessary to contain OAM flows & bound OAM responsibilities
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Maintenance Points (MP) & Intermediate Points (IP)
Customer Domain
Provider Domain
Operator Domain Operator Domain
Operator Domain
Eth Access MPLS Core MPLS Access
Customer CustomerService Provider
MPLS Domain MPLS Domain
Maintenance PointIntermediate Point
• Location of MPs and IPs is dependent on Business Models & Deployment Scenarios
Network OAM
Service OAM
PW/MPLS OAM
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VPLS OAM – How diff. layers come together?
Ethernet link OAM
PW/MPLSOAM
EoSONET OAM
Other OAM
Network OAM
Service OAM
Transport Links
Network
Services
• OAM Interworking possible to utilize OAM across Layers• However, each layer must support OAM capabilities independently
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Maintenance Entities – MP2MP Case
ETH_TFPTH_FP ETH_FP
ETHLink ETH_FP ETH_FP
ETHLink
ETH_TFPETH_FPETH
Link
ETH_FPETHLink
Service Provider Y
Network Operator BNetwork Operator AUser X User X
UNI NNI UNI
UNI
ETH_TFPETH_FP
ETH_TFPETH_FP ETH
Link
UNI
ETH_FP ETH_FP
UNI_C to UNI_C maintenance entities
UNI_N to UNI_N maintenance entities
Intra Domain MEs Intra Domain MEs
Access Link MEs Access Link MEsInter Domain ME
ETH ETH
• Note: Not all these MEs may be needed
• MPs realize Maintenance Entities (MEs)
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draft-sajassi-mohan-l2vpn-vpls-fm-00.txt
Fault Management
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Fault Management
• Typical steps involved– Fault Detection– Fault Verification– Fault Isolation– Fault Notification– Fault Recovery
• Focus of this draft is specifically on:– Fault Detection– Fault Verification– Fault Isolation
• OAM Messages are sent across MEs within OAM domain
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Fault Management - Detection
• CC (Continuity Check)– Heartbeat message sent periodically– Sender does not expect acknowledgement– Receiver starts timer to expect periodic CC from sender– Loss of n consecutive CCs results in failure detection– Failures detected include:
• Hard and soft failures
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Fault Management - Verification
• Non-intrusive Unicast Loopback– Verify the detected fault– Sender sends a request to receiver and expects a response
• Receiver will typically be the one from whom CCs stop• Verification is done via the response
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Fault Management - Isolation
• TraceRoute– Sender sends a single request and IPs and receiver respond.– Only selective Intermediate Points (IPs) respond – Ethernet fault isolation is more challenging due to age-out of MAC
addresses (typically 5 minutes intervals)
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Fault Management – Information Elements
• Common OAM Information– OAM EtherType– OAM Version– OAM OpCode– Domain Level– Service ID – Transaction ID
• Requirements (Information Elements) need to be discussed/agreed for VPLS
– Exact details (e.g.) frame formats will be worked out in coordination with IEEE 802.1
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draft-mohan-sajassi-l2vpn-vpls-pm-00.txt
Performance Management
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Performance Management
• Typical steps involved– Measurement of Performance Parameters
• Collection of managed objects information• Calculation/Measurement of performance parameters
– Determination of compliance across:• Service Level Specifications• Network Level Specification
• Focus of this draft is specifically on:– Frame Loss Measurements– Frame Delay Measurements– Frame Delay Variation Measurements– Availability Measurements– Others parameters
• OAM Messages are sent across MEs within OAM domain
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Performance Management – Measurement Mechanisms Options
• Level of accuracy– Statistical Methods
• Sampling via OAM frames done to estimate the data path behavior • Least accurate since OAM frames behavior could be quite different from data path
behavior– Data path managed objects using management plane
• Data path managed objects used to make measurements, however, this information is inserted via management plane
• Slight impact on accuracy since delay across data plane and management plane interactions
• Mostly software based changes required– Data path management objects using data plane
• Data path managed objects used to make measurements, however, this information is inserted via data plane
• High accuracy since no delay across data plane and management plane interactions• Hardware based changes needed in this case
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Performance Management – Collection Method
• Generic method vs. specific method for specific managed objects
– Recommendation for generic method e.g. use of TLVs
• Solicited (requiring response) vs. Unsolicited (not requiring response)
– Recommendation to use both– Possible to extend the Loopback and CC methods
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Performance Management – Performance Parameters Measurements
• Frame Loss– Unsolicited Method– Solicited Method– FL = |CT2-CT1| - |CR2-CR1|
• Frame Delay– Round-trip or two-way delay– Sender compares sent-timestamp with timestamp at receiving response
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Performance Management – Performance Parameters Measurements
• Frame Delay Variation– FDV = FD (max) – FD (min)
• Availability– Availability = (# of available time intervals)/(# of total time intervals)
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What’s next?
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Next Steps
• Work Group Items?– Further discussion & participation on VPLS OAM FM & PM work
• Coordination with: – L2VPN Requirements– Management Framework for OAM
• Continued coordination with other bodies– IEEE 802.1– ITU-T Q.3/13– MEF
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