230 likes | 392 Views
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)
E N D
draft-sajassi-mohan-l2vpn-vpls-fm-00.txtdraft-mohan-sajassi-l2vpn-vpls-pm-00.txtdraft-sajassi-mohan-l2vpn-vpls-fm-00.txtdraft-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) • Nortel & Cisco colleagues • Other Standards Participants • ITU-T (Q.3/13) • MEF • IEEE (802.1 & 802.3)
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
Ethernet Layer VPLS OAM Layering – Service Layer Customer Service Provider Customer Eth Access MPLS Core MPLS Access Device View CE U-PE B B N-PE P P P N-PE P U-PE CE Example Scenario with Single Service Provider Network
OAM Domain – Service/Network Customer Service Provider Customer Eth Access MPLS Core MPLS Access Customer Domain Provider Domain Operator Domain Operator Domain Operator Domain • Domains necessary to contain OAM flows & bound OAM responsibilities
Maintenance Point Intermediate Point Maintenance Points (MP) & Intermediate Points (IP) Customer Service Provider Customer Eth Access MPLS Core MPLS Access Customer Domain Service OAM Provider Domain Network OAM Operator Domain Operator Domain Operator Domain PW/MPLS OAM MPLS Domain MPLS Domain • Location of MPs and IPs is dependent on Business Models & Deployment Scenarios
Services Service OAM Network Network OAM Transport Links Ethernet link OAM PW/MPLS OAM EoSONET OAM Other OAM VPLS OAM – How diff. layers come together? • OAM Interworking possible to utilize OAM across Layers • However, each layer must support OAM capabilities independently
Maintenance Entities – MP2MP Case • MPs realize Maintenance Entities (MEs) • Note: Not all these MEs may be needed
Fault Management draft-sajassi-mohan-l2vpn-vpls-fm-00.txt
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
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
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
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)
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
Performance Management draft-mohan-sajassi-l2vpn-vpls-pm-00.txt
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
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
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
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
Performance Management – Performance Parameters Measurements • Frame Delay Variation • FDV = FD (max) – FD (min) • Availability • Availability = (# of available time intervals)/(# of total time intervals)
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