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1 draft-sajassi-mohan-l2vpn-vpls-fm-00.txt draft-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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2 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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3 Scope of Current Work 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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4 General Concepts – L2 OAM Framework
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5 VPLS OAM Layering – Service Layer CEU-PE N-PE CEBBPPPP Device View Example Scenario with Single Service Provider Network Ethernet Layer Eth AccessMPLS CoreMPLS Access Customer Service Provider
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6 OAM Domain – Service/Network Eth AccessMPLS CoreMPLS Access Customer Service Provider Customer Domain Provider Domain Operator Domain Domains necessary to contain OAM flows & bound OAM responsibilities
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7 Maintenance Points (MP) & Intermediate Points (IP) Customer Domain Provider Domain Operator Domain Eth AccessMPLS CoreMPLS Access Customer Service Provider MPLS Domain Maintenance Point Intermediate Point Location of MPs and IPs is dependent on Business Models & Deployment Scenarios Network OAM Service OAM PW/MPLS OAM
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8 VPLS OAM – How diff. layers come together? Ethernet link OAM PW/MPLS OAM 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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9 Maintenance Entities – MP2MP Case Note: Not all these MEs may be needed MPs realize Maintenance Entities (MEs)
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10 draft-sajassi-mohan-l2vpn-vpls-fm-00.txt Fault Management
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11 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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12 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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13 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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14 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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15 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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16 draft-mohan-sajassi-l2vpn-vpls-pm-00.txt Performance Management
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17 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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18 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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19 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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20 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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21 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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22 What’s next?
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23 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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