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10 fn s21


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10 fn s21

  1. 1. Verizon‘s Requirements for IP/MPLS-Based Carrier Ethernet Networks Andrew G. Malis & Drew Rexrode Verizon Communications Future-Net 2010
  2. 2. Introduction • Public Ethernet services are exploding in popularity • External Ethernet interface to the customer does not necessarily mean ―Ethernet inside‖ – The Internet Engineering Task Force (IETF) has standardized mechanisms for providing point-to-point and multipoint public Ethernet services over IP/MPLS-based infrastructures • This talk discusses Verizon‘s requirements for such solutions, including functionality, conformance to Metro Ethernet forum (MEF) service definitions, reliability, scalability, QoS, performance monitoring, OAM, testing, and certification 2
  3. 3. Why Are Ethernet Services Popular? • Ubiquity and low cost of Ethernet interfaces in customer equipment, universal experience with Ethernet in LANs, and perceived simplicity • Successful marketing of the ―Ethernet‖ brand by vendors, IEEE, MEF, and others – Little resemblance with original DIX Ethernet specifications, from physical layer on up (e.g., today‘s Ethernet is mostly point-to-point or ring-based rather than CSMA-CD at the physical layer) – Most everything has changed except for the basic frame format – and jumbograms (large frames up to 9K bytes) change even that • Plenty of competition and favorable pricing by service providers 3
  4. 4. MEF Carrier Ethernet Service Definitions Port-Based VLAN-Based Connectivity Model (All to One Bundling) (EVC identified by VLAN ID) E-Line Ethernet Private Line Ethernet Virtual Private Line (point-to-point EVC) (EPL) (EVPL) E-LAN Ethernet Private LAN Ethernet Virtual Private LAN (multipoint-to-multipoint EVC) (EP-LAN) (EVP-LAN) E-Tree Ethernet Private Tree Ethernet Virtual Private Tree (rooted multipoint EVC) (EP-Tree) (EVP-Tree) • Three service types based on the three Ethernet Virtual Connection (EVC) types • Two ―UNI Types‖ determine whether services are ‗private‘ or ‗virtual‘ – Port-based (All to One Bundling)  single EVC (transparency, but uses an entire port per service) – VLAN-based  ‗N‘ EVCs per UNI (not as transparent, but multiple services per port) • Services are defined by combination of connectivity model and ‗UNI Type‘ • Also Ethernet-based access services to Layer 3 VPNs or dedicated Internet access 4
  5. 5. ―Enterprise-Class‖ Ethernet Limitations • ―Enterprise-class‖ Ethernet switching has shortcomings as a basic for public Ethernet services – Few features for high availability in protocols or equipment – Scaling limits on MAC addresses, VLAN IDs, and spanning tree topology limit the size of native Ethernet networks – Spanning tree routing may take seconds to (occasionally) minutes to re- converge • Early Ethernet providers found that enterprise-class Ethernet cannot naively be deployed for reliable carrier services 5
  6. 6. Evolving and Scaling Ethernet Services • A typical ―early‖ public Ethernet service provider probably uses Ethernet switches and Q-in-Q for customer separation • Typical end user services are – Ethernet Private LAN (EP-LAN) – Ethernet Virtual Private LAN (EVP-LAN) – Ethernet Private Line (EPL) – Ethernet Virtual Private Line (EVPL) – Each of these services requires the use of a provider VLAN tag • As the service becomes successful, the provider will encounter the usual Ethernet scaling limitations – MAC address scaling – VLAN tag scaling (4K customer limit) – Switching capacity limits 6
  7. 7. Typical ―Early‖ Ethernet Service Network • Characterized by organic PE growth driven by customer PE location PE GigE/LAG PE • All switches are ―edge switches‖ PE PE • May be some number of PE redundant links PE PE PE • 802.3ad Link Aggregation may also be used for resiliency or PE PE PE for additional BW between PE switches PE PE • Flat network with spanning PE tree routing – Network diameter is limited, often to metro scope PE – Provider Edge Switch 7
  8. 8. Emergence of ―Carrier Ethernet‖ • Limitations in enterprise-class Ethernet have led to the development of ―Carrier Ethernet‖ • Meant to address unique requirements for carrier Ethernet services, including Verizon‘s services – Scaling to support a large number of customers – Scaling to support large numbers of switches and customer interfaces – Support both point-to-point (E-Line) and multipoint (E-LAN and E-Tree) services – Support for both port-based and VLAN-based services – Support for QoS other than best-effort to support QoS-based SLAs – Sub-second outage restoration and routing convergence to support availability SLAs – Policing and shaping to support sub-rate services (e.g., 200 Mbps service on a physical GigE interface) 8
  9. 9. IETF Ethernet Services Support • Point-to-point pseudowires (PWs) to carry layer two frames, including Ethernet, over IP/MPLS networks • Extends the MPLS LDP protocol to signal pseudowire establishment • IETF extended PWs to a multipoint Ethernet service, VPLS (Virtual Private LAN Service) • PWs and VPLS extremely popular, implemented by most every router vendor and in wide use by service providers world-wide • Verizon uses both point-to-point PWs and VPLS to provide customer Ethernet services 9
  10. 10. IP/MPLS Forum Ethernet Services Support • Extended IETF-defined PWs to support non-similar endpoint interworking – Supports point-to-point Ethernet-to-Frame Relay, Ethernet-to-ATM, and ATM-to-Frame Relay interworking over MPLS PWs – Very useful for multiservice convergence, and to support customers with a variety of access methods – Can support applications such as hub location with GigE access, and low-speed Frame Relay spokes – Supports interworking of IP packets via ARP Mediation, and bridged services by interworking native Ethernet with Ethernet frames encapsulated by FR or ATM – Can also support VPLS endpoints with FR or ATM-attached customer equipment 10
  11. 11. H-VPLS vs. VPLS+PBB • VPLS and H-VPLS as originally defined by the IETF cannot meet Carrier Ethernet service scaling requirements: – 10s to 100s of thousands of EVCs – Number of E-LAN bridging instances per edge switch/LER – Up to millions of customer MAC addresses • For these reasons, the IETF is now defining the combination of VPLS in the core with Provider Backbone Bridges (PBB, 802.1ah) at the edge 11
  12. 12. Scalable Network Architecture – PBB + MPLS PB PB N-PE BEB PBEB BEB PB N-PE BCB BEB PB BEB BCB N-PE PBEB PBEB P P BEB BEB /PE PB PB PB • Metro Network Dedicated to Ethernet • Less touch points for cross-metro • MPLS core leveraged across Service services multiple services (e.g., Ethernet, L3 VPNs) • Investment Protection • PBB (B-VID) VPLS instance (reduce PW Meshiness) • Scalable and mature control plane • Hierarchy with PBB • Broadcast containment per service • Leverage control plane to ease • Administrative Traffic Eng. across core (via MMRP/BGP-AD) administration (BGP-Auto Discovery, TE) • Operations skill set / OSS Leverage • PBB MAC hiding 12
  13. 13. PBB-VPLS— MAC Scaling and Customer-Addressing Awareness PE-rs PE-rs MTU-s MTU-s MPLS MPLS MTU-s H-VPLS PBB-VPLS MTU-s No. of MAC addresses/node No. of MAC addresses/node 100,000s 100,000s 1000s Customer MACs 1000s Backbone MACs MTU-s PE-rs 0 MTU-s PE-rs 0 • ―Hub‖ PE-rs get visibility of 100,000s of MACs • MAC tables reduced: one B-MAC per • High customer-addressing awareness node • No customer-addressing awareness 13
  14. 14. PBB-VPLS Benefits — Service/Pseudowire Scaling and Customer-Service Awareness B B PE-rs PE-rs B B B B B B B MTU-s B MTU-s MTU-s H-VPLS VPLS + PBB No. of services-PW/node No. of services-PW/node 100,000s 100,000s Customer services 10,000s 10,000s Customer PWs 1000s 1000s Backbone services 0 100s Backbone PWs 0 MTU-S MTU-S PE-rs PE-rs MTU-S MTU-S PE-rs PE-rs 14
  15. 15. OAM Specifications • The IEEE, ITU-T, and MEF have defined Ethernet OAM (Operations, Administration and Maintenance) specifications to allow fault detection and correction. These include: – Link OAM: IEEE 802.3-2005, Clause 57 • Enables monitoring and troubleshooting of native Ethernet links – Ethernet Local Management Interface (E-LMI): MEF 16 • Provides EVC status • Enables automatic configuration of Customer Equipment (CE) – Connectivity Fault Management (CFM): IEEE 802.1ag • Enables monitoring and troubleshooting of VLANs within a network • Supports multiple views (Customer, Service Provider, Operator) – Service OAM: ITU-T Y.1731 • Extends CFM to include additional FM capabilities • Performance Monitoring (PM) 15
  16. 16. Carrier Ethernet over MPLS Testing • Requires documentation and references – MEF, BBF, IETF, IEEE • Automation – Definitive Parameters 16
  17. 17. 802.1 q-in-q/ad and 802.1ah - Service Tunneling Testing Scenario (Example) BCB1 BCB2 G.8031 Tunnel protection group PBBN BEB1 BEB2 BEB3 BEB4 ISID ISID ISID ISID ISID ISID ISID ISID BEB5 BEB6 Q-in-Q /82.1ad ISID ISID ISID CEs VLAN 100 VLAN 100 VLAN 100 VLAN 100 0000.c004.0108 0000.c004.0106 0000.c004.0102 0000.c004.0105 0000.c004.0109 0000.c004.0107 0000.c004.0103 0000.c004.0104 17
  18. 18. Carrier Ethernet over MPLS Certification • ROI • Man Hours • Time to Market • Resources 18
  19. 19. Conclusions • Verizon‘s Carrier Ethernet services must meet stringent requirements for: – Conformance to Metro Ethernet forum (MEF) service definitions – Scalability to support customer growth – Reliability, resilience, OAM for troubleshooting and performance monitoring, to support high service availability – Standards-based certification – Pre-deployment and post-deployment testing 19
  20. 20. Questions? Thank you! 20