MEF Protection Work Pascal Menezes Technical Contributor June 3 rd 2003

Agnostic to any transport and its related protection schemes. Agnostic to any topology –Does not rely on a certain topology for protection (ex: ring) –Can work with any topology (ring, mesh, mixed, etc) –Degree of protection is dependent on the richness of the redundancy of the topology Co-exist with any transport protection schemes (ex: SONET, RPR, 802.1d. Primarily designed for the protection of EVCs. –Based on MPLS based schemes because of the layer 2 service work in IETF for PPVPN (ex: VPLS, VPWS, etc) and PWE3 WGs. This was the scheme chosen because of scalability and inter-MEN connectivity advantages. –It is transparent to IEEE schemes (STP, Link Agg, etc) and it assumes IEEE protection schemes are part of the protection of an Ethernet transport mechanism (ie: it is part of the transport mechanism of the provider). Subscriber’s protection scheme is transparent (ie: STP, multi- homed) Extensions to the PRMs for IEEE based technologies –Looking into 802.1ad work and how to extend the framework interworking Motivations

Work done in the MEF Protocol and Transport Group –Protection Requirements Document Status is Straw Ballot –Protection Framework Document Status is Straw Ballot –MPLS Protection Implementation Agreement Status is Straw Ballot MEF Protection Work Items

MEF Architecture External Reference Model Subscriber MEF UNI Ethernet Interworking NNI Metro Ethernet Network (MEN) Autonomy X Other Transport Networks Network Interworking NNI Metro Ethernet Network (MEN) Autonomy X Service Interworking NNI Other Service Networks (Internet, PPP, FR, ATM) Metro Ethernet Network (MEN) Autonomy Y Network Interworking NNI Subscriber MEF UNI Subscriber Other UNIs Subscriber MEF UNIs

802.3 PHY ATM VP HOVC STM-N ATM VC HOVC STM-N LOVC HOVC STM-N MPLS PHY OTUk OCh OTM-n ODUk other MPLSPDHOther IP MEN Applications (Voice, Video, Data, etc) IP HOVC STM-N MPLS MPLS VC Transport Layer (s) Application Services Layer (s) IP TCP/UDP Other Protocol Suite(s) Transport Layers Application Layers Ethernet Services Medium (Fiber, Copper, Coax, wireless, etc.) Ethernet Service Layer Ethernet Layer MEN Layered Model

MEF Ethernet Virtual Connection (EVC) Model Metro Ethernet Network Customer Edge (CE) Customer Network Element Network Element Network Element Network Element Customer Network Customer Edge (CE) User Network Interface (UNI) User Network Interface (UNI) Ethernet Virtual Connection (EVC) UNI = Service Attributes EVC = Service Attributes

Protection switching times. Failure detection requirements Protection resource allocation requirements Topology requirements Failure notification requirements Restoration and revertiveness requirements Transparency for end user Security requirements MEF Protection Requirements

Connectivity restoration time –Sub 50msec –Sub 200msec –Sub 2 sec –Sub 5 sec Protection type –1+1 –1:1 –1:n –m:1 –m:n Revertive or non-revertive mode Reversion time Degrade condition threshold (ex: packet loss) QoS preservation End to End Protection Service Level Specifications

Other Transport (Protection) Ethernet (No Protection) CE Metro Ethernet Network (MEN) CE End-to-End Protection Service Level Specification (SLS) Transport Sub-Network Transport Sub-Network Transport Sub-Network Other Transport (Protection) Transport & Protection SLS

Backbone Ring NE Access Ring NE Access Mesh WAN 1 Backbone Ring Access Ring NE Access Mesh NE Metro Ethernet Network (MEN) End-to-End Protection Service Level Specification (SLS) WAN 2 Topology & Protection SLS

MEF Protection Reference Model (PRM) End to End Path Protection EEPP Aggregated Line and Node Protection ALNP MEF Protection Mechanism Topology Transport Ethernet Services Parameters (Protection EVC Service Attributes, Traffic Parameters, etc) Service Level Agreements SLA Application Protection Constraint Policy APCP

End-to-End Path Protection (EEPP) Aggregated Line & Node Protection ALNP Topology Transport ALNP Backup LSPs 1+1 EEPP Protection Type 50 Msec Restoration Time QoS Preserved Protection Service Level Specification Application Protection Constraint Policy Availability Packet loss Delay Jitter Subscriber Service Level Agreement Application Protection Constraint Policy (APCP) EVC Availability EVC MTTR etc.. Ethernet Service Attributes Ethernet Services Parameters

NE Ingress NE Egress NE Backup LSP Backup LSP Primary LSP Aggregated Line and Node Protection (ALNP)

Aggregated Node and Line Protection (ALNP) CE A NE 3 NE 8 NE 4 NE 9 CE Z NE 10 NE 2 NE 5 NE 7 NE 1 NE 6 EVC

NE Ingress NE Egress NE Backup LSP Backup LSP Primary LSP NE Secondary LSP End-to-End Path Protection (EEPP) Redundant Network Primary Network

End-to-End Path Protection (EEPP) CE A NE 3 NE 8 NE 4 NE 9 CE Z NE 10 NE 2 NE 5 NE 7 NE 1 NE 6 EVC

Backbone Ring NE Access Ring NE Access Mesh WAN 1 Backbone Ring Access Ring NE Access Mesh NE Metro Ethernet Network (MEN) WAN 2 NE Primary LSP Backup LSP Secondary LSP PRM Example

Protection And Protected Transport Sub-Networks

Generic approach – PRM interoperability with any kind of transport / topology / protected MPLS- subnetwork / logical-link. Failures within the protected-transport/subnetwork are provided by itself. PRM is required for completing the solution in the border between the protected transport/subnetwork and other subnetworks. Requires indications from the lower layer. Indications achieved either by the lower-layer or by an OA&M procedure that operates above it. PRM does not require knowledge of internal structure of the protected subnetwork. PRM and Protected Transport Sub-Networks

NE CE NE CE NE PRM and RPR RPR Sub-Network No protection needed GE Links RPR Sub-Network Protection needed

Two rings, each protected by technology-specific means, interconnected with point-to-point links. PRM is required for protecting the P2P links and the border nodes (for example, protection tunnel for node A in blue). A PRM and SONET SONET Sub-Network SONET Sub-Network

A topology containing protected-transport subnetwork as well as unprotected P2P links. Protected Transport / Subnetwork A DB CE F G H Example Network Unprotected link

Failures within the protected subnetwork are protected by its native capabilities. Failure of border nodes like node A are not protected by the transport/subnetwork. Protected Transport / Subnetwork A DB CE F G H Where is PRM Needed?

Protection-tunnels are required only for protection of border nodes (unprotected links/nodes). Failure of a link leading to the border node activates the operation of PRM – switch to the protection tunnel. Protected Transport / Subnetwork A DB CE F G H PRM Operation in Protected Transport Sub- Networks

When the failed node is at the exit of an LSP from the protected subnetwork, the entry node is the one to activate the PRM – switch to the protection tunnel. This requires receipt of indication about the failure from the protected transport subnetwork or MPLS OAM/Hello. Protected Transport / Subnetwork A DB CE F G H PRM and Egress Border Failure Case

Some transports have means for indicating about failures and about their type and place. OAM procedures on LSPs Heartbeat on links: ex: RSVP Hello Ext. Node Failure Indications in Protected Transport Subnetworks

The PRM scheme is generalized to interoperate with protected-transports / unprotected-transports / protected-subnetworks / logical-links. PRM does not have knowledge of internal structure of the protected subnetwork. Protected subnetworks can use any kind of protection mechanism. Subscribers protection mechanisms are transparent The PRM is a multi-layers protection model that co-exist together. Summary

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