ETHERNET KEPT Provider Link State Bridging Gerard Jacobs Senior Solutions Architect
Agenda > Network Visions > Carrier Ethernet > Provider Link State Bridging (PLSB) > Summary
Network Visions HYBRID L1 LP IP Ethernet GFP SDH Wavelength
Network Visions HYBRID CONVERGED L1 LP GFP SDH IP Ethernet L1 LP L2-LP E-VPN Ethernet IP Wavelength Wavelength
Agenda > Network Visions > Carrier Ethernet > Provider Link State Bridging (PLSB) > Summary
Carrier Ethernet Requirements Ethernet Considerations in the Carrier Space: >Scalability >Security: >Delineation >Customer Separation >Attacks >Reliability >QoS and SLA >OAM Campus Site COMPANY A Headquarters COMPANY B Branch Office COMPANY B Branch Office COMPANY B Ethernet VPNs Virtual Switches Data Center COMPANY A
Evolution of Carrier Ethernet 802.1aq PLSB Robust L2 Control Plane Y.1731 Performance Management 802.1ag Fault Management 802.1Qay PBB-TE Traffic Engineering Proactive Management Service and Infrastructure diagnostics 802.1ah PBB Scalable, Secure Dataplane Ethernet has steadily evolved to meet the needs of Service Providers
MiM / 802.1ah / PBB >Customer frame is transparently tunnelled from UNI to UNI hiding customer SA in PBB network >Customer separation based on a especial label (I-SID) >Addressing separation: >SP core network only learns UNI MACs >No DoS or MAC explosion 802.1ah Provider Backbone Bridges Payload Ethertype C-VID Ethertype SA DA I-SID Ethertype B-VID Ethertype B-SA B-DA SA = Source MAC DA = Destination MAC VID = VLAN ID C-VID = Customer VID I-SID = Service ID B-VID = Backbone VID B-DA = Backbone DA B-SA = Backbone SA X Y A B MAC X CE PBB network CE MAC Y UNI MAC=A UNI MAC=B
Provider Backbone Bridging (PBB) Payload C-VID S-VID SA DA I-SID B-VID B-SA B-DA 802.1ah Provider Backbone Bridges Created to bridge.1ad networks together in a scalable way Supports E-LAN, E-TREE, and E-LINE services Secure and scalable no C-MAC learning in the core, > 16M services per metro Plug and play Ethernet forwarding Single endpoint provisioning Efficient handling of broadcast / multicast distributed replication model Several control plane options for loop-free frame forwarding xstp, SMLT or PLSB 802.1ad Interfaces Provider Bridge Network (802.1ad) Provider Backbone Bridge Network (802.1ah) Provider Bridge Network (802.1ad) 802.1ah Interfaces
Provider Backbone Transport (PBT) Payload C-VID S-VID SA DA I-SID B-VID B-SA B-DA P2P traffic engineered Ethernet tunnels Initially supports E-LINE services Services multiplexed inside a single tunnel Reuses existing Ethernet forwarding plane forward based on B-MAC+B-VID Hop-by-hop specification of tunnel path to achieve objectives in terms of delay, cost, diversity, load sharing, etc. Tunnels can be setup by management (MEM, CLI) or signaling Bandwidth reservation and CAC can be implemented by management system (MEM) 50 ms recovery with fast 802.1ag CFM OAM Active PBT trunk 802.1Qay Provider Backbone Bridges-TE VPN endpoints Standby PBT trunk
Agenda > Network Visions > Carrier Ethernet > Provider Link State Bridging (PLSB) > Summary
What is PLSB? > PLSB is a Spanning-Tree Protocol replacement for PBB STP is slow to converge; typically 30 40 seconds STP blocks links effectively stranding bandwidth > Control Plane IGP + PBT operation MEM not required to achieve deterministic forwarding IGP (Interior Gateway Routing Protocol) IS-IS used to dynamically find the shortest path to the destination PBT like forwarding dynamically updated > Data Plane PBB encapsulation for forwarding B-MACs distributed by IS-IS 12
The Current Mode with STP root A X X X The STP protocol distributes bridge PDUs (BPDUs) to compute a single spanning tree. Ports not on the tree are blocked and not used for multicast traffic. Unknown destinations are broadcast, and reverse learning used to build forwarding tables. D 13
PLSB Fundamentals > Apply Link State routing to Ethernet, now that PBB has placed all backbone MACs under provider control > flooding is disabled & all ports are unblocked > Control plane configures shortest path unicast and multicast connectivity between PBBs > PLSB delivers a better B-MAC layer for MAC-in-MAC by elimination of the Spanning Tree Protocol : > PBB s MAC-in-MAC keeps C-MAC state at the edge > C-MAC flooding & broadcast maps to scoped B-MAC multicast > Ethernet s network-global identifiers allow all information (B-MAC and Service Identifiers) to be flooded by a single protocol, IS-IS : > PLSB has no link-local state to manage. 14
PLSB Implementation PLSB discovers the network automatically setting up a shortest path distribution tree without blocking any links Each node creates its Shortest Path tree to all other nodes in the network Network Topology Shortest Path tree from ES1 15
Defining Services using PLSB > As PBB service endpoints (ISIDs) are added, all PLSB nodes will be aware of all service locations. > Each PLSB node will know if it is on the shortest path for each ISID and install the appropriate FIB state to ensure connectivity, thereby creating per service multicast tree 2 16 Shortest Path tree from ES1 Multicast tree for all nodes supporting ISID 100 (ES1, ES7, ES11)
PLSB Loop Suppression 17 > In any distributed system transient loops will occur Even transient multicast loops can be catastrophic packet multiplication rate is limited only by the RTT, Ethernet today blocks ports until converged (STP) > PLSB ensures that the path between any two nodes in BEB BEB each direction is the same for both BEB unicast and multicast paths : PB so in a converged network PB PBBN each bridge knows the interface on which to expect any given BEB BEB source; it is already in the FDB > We can trivially modify bridge source learning to audit multicast convergence on a frame by frame basis : need to learn this SA? drop this SA if unknown BEB
Agenda > Network Visions > Carrier Ethernet > Provider Link State Bridging (PLSB) > Summary
Making Ethernet Simple & Cost Effective Provider Backbone Bridges (IEEE 802.1ah PBB, Mac-in-Mac) Provider Backbone Transport (IEEE 802.1Qay PBB-TE) Ethernet OAM (IEEE 802.1ag, ITU Y.1731) Provider Link State Bridging (IEEE 802.1aq) > Customer separation > Scalability millions of unique service instances > Service agnostic > Connection oriented > Traffic engineering, hard QoS, 50ms > Guaranteed SLA > Rapid resolution to network issues > Differentiated services / SLAs > Bringing operational values of circuit-based networks to Ethernet > Ensures shortest path forwarding for unicast/multicast/broadcast traffic > Massive Scalability for arbitrary network topology/architecture 19 Nortel Confidential Information
Thank you! ETHERNET MADE SIMPLE 20 Nortel Confidential Information