【正文】 PE device ~ BEB。IETF 86 – Tutorial IEEE Media Access Control Bridges and Virtual Bridged Local Area Networks Patricia Thaler, Norman Finn, Don Fedyk, Glenn Parsons, Eric Gray March 10, 2023 Contents ? IEEE Overview ? Bridge architecture ? Data plane ? Provider Bridges (PB) /QinQ/ ? Provider Backbone Bridges (PBB) /MACinMAC/ ? Edge Virtual Bridging (EVB) ? Control plane ? Rapid Spanning Tree Protocol (RSTP), Multiple Spanning Tree Protocol (MSTP) ? Multiple Registration Protocol (MRP) ? Shortest Path Bridging (SPB) ? Software Defined Networking (SDN) aspects ? Enhancements to bridging of ? Operation, Administration, and Maintenance (OAM): Connectivity Fault Management (CFM) ? Protection switching ? Management ? Quality of Service (QoS) ? Enhanced transmission selection (ETS) ? Prioritybased flow control (PFC) ? Congestion Notification (CN) ? Stream Reservation Protocol (SRP) ? Credit based shaper ? Preemption and time scheduled queuing ? Policing ? Other standards not covered by this tutorial ? Link Aggregation ? Link Layer Discovery Protocol (LLDP) ? Time synchronization ? Audio video bridging systems ? Bridge port extension ? Security ? Summary ? References ? Abbreviations IEEE 4 IETF 86 – Tutorial BRIDGE ARCHITECTURE March 10, 2023 IEEE 11 Basic Principles ? MAC addresses are “identifier” addresses, not “l(fā)ocation” addresses ? This is a major Layer 2 value, not a defect! ? Bridge forwarding is based on ? Destination MAC ? VLAN ID (VID) ? Frame filtering for only forwarding to proper outbound ports(s) ? Frame is forwarded to every port (except for reception port) within the frame39。s VLAN if it is not known where to send it ? Filter (unnecessary) ports if it is known where to send the frame (. frame is only forwarded towards the destination) ? Quality of Service (QoS) is implemented after the forwarding decision based on ? Priority ? Drop Eligibility ? Time IEEE 12 Control Plane Separated from Data Plane ? Control protocols are implemented as Higher Layer Entities ? External Agent may provide control instead of the distributed protocols ? The data plane is prised of ? A MAC Relay and ? At least two ports IEEE 13 Data Plane Control Plane Relay Port Port External Agent MAC Bridge Higher Layer Entities Simplified “baggy pants” model LAN Media Access Method Specific Functions IEEE . Ether 80 Bridging LAN see Figure 82 – “VLANaware Bridge architecture” of for more details IETF 86 – Tutorial DATA PLANE March 10, 2023 IEEE 15 Data Plane Today ? today is (Revision 2023 is ongoing) ? Note that if the year is not given in the name of the standard, then it refers to the latest revision, . today = and = ? already involves ? QinQ = Provider Bridges (PB) [IEEE ] ? MACinMAC = Provider Backbone Bridges (PBB) [IEEE ] ? Edge Virtual Bridging (EVB) is also part of today?s data plane ( not yet amended to ) ? is not only about 12bit CVLANs any more IEEE 16 Data Plane Actions ? Ingress Port (Action Set1) ? Filtering (drop), (un)tagging, VID translation, de/encapsulation ? Relay (Action Set2) ? Forwarding, filtering ? Egress Port (Action Set3) ? Filtering, (un)tagging, VID translation, de/encapsulation, metering, queuing, transmission selection IEEE 17 Data Plane Frame out Frame in Relay Ingress Port (Action Set1) Egress Port (Action Set3) MAC Bridge Ingress Port (Action Set1) (Table1) Relay (Action Set2) (Table2) Frame in Frame out MAC Bridge Egress Port (Action Set3) (Table3) redrawn (“baggy pants” is simple) Network Overlays Example IEEE 18 Backbone Provider Network Customer Network Provider Edge Bridge Provider Edge Bridge Provider Bridge Network (PBN) Core Bridge Provider Edge Bridge Provider Edge Bridge Core Bridge Provider Bridge Network (PBN) Customer Network Customer Network Customer MAC Customer MAC Backbone MAC Backbone Edge Bridge Backbone Edge Bridge Provider Backbone Bridge Network (PBBN) Backbone Core Bridge Very rough analogy of IETF concept to concept: P device ~ BCB。 CE device ~ CMAC bridge BEB BEB BCB Network Virtualization Is Based on the Data Plane ? Data plane evolution [up to ] ? it is not plicated ? ~ may think of tag stacking ? Provider Bridges (PB, QinQ) ? Scalability ? Overlaying virtual works ? 4K VLAN problem solved ? Provider Backbone Bridges (PBB, MACinMAC) ? Scalability ? 24bit ISID as a single virtual work ID ? Fet about the 4K VLAN problem ? Separation ? MAC address space separation (CMAC vs. BMAC) ? Service layer is separated from transport layer (ISID vs. BVID) ? Overall ? Uniform forwarding kept: based on Destination MAC (DA) and VID ? L2 data plane provides powerful virtualization ? There may be several levels of tagging or encapsulation IEEE 19 Payload Ethertype Src Addr Dst Addr PB Payload Ethertype CVID Ethertype SVID Ethertype CSA CDA Payload Ethertype VID Ethertype SA DA PBB Payload Itag Btag BMAC Stag Ctag Ethertype CVID Ethertype SVID Ethertype CSA CDA ISID Ethertype BVID Ethertype BSA BDA Virtual Networks and Overlays ? Virtual work names do not bound their application! ? A lot of flexibility is provided, two examples shown here ? Using all L2 virtual work overlays ? Can be used in data center and campus works too, not only in provider environment ? IP is a native overlay on Ether ? IP payload can be . right after Itag ? Host can be a Virtual Machine ? PBB can be