1. doc.: IEEE 802.11-04/0981r1 TGs Reference Architecture Considerations September 6, 2004 Tricci So & W. Steven Conner.Slide 1 TGs ESS Mesh System Reference Architecture Considerations TGs ESS Mesh System Reference Architecture Considerations Prepared by Tricci So - Nortel Networks W. Steven Conner - Intel

2. doc.: IEEE 802.11-04/0981r1 TGs Reference Architecture Considerations September 6, 2004 Tricci So & W. Steven Conner.Slide 2 MotivationsMotivations Considering the TGs System Architecture Framework......Considering the TGs System Architecture Framework...... Where should we start???

3. doc.: IEEE 802.11-04/0981r1 TGs Reference Architecture Considerations September 6, 2004 Tricci So & W. Steven Conner.Slide 3 What Have TGs Five Criteria Said?  6.2 Compatibility  IEEE 802 defines a family of standards. All standards shall be in conformance with the IEEE 802.1 Architecture, Management and Interworking documents as follows: 802. Overview and Architecture, 802.1D, 802.1Q and parts of 802.1f. If any variances in conformance emerge, they shall be thoroughly disclosed and reviewed with 802. Each standard in the IEEE 802 family of standards shall include a definition of managed objects, which are compatible with systems management standards.  ESS Mesh specifies one possible Wireless Distribution System (WDS) that behaves in every respect as an IEEE 802.11 Infrastructure Mode network. As such, it is entirely compatible with the IEEE 802.11 architecture and, by inference, compatible with the IEEE 802 architecture, including IEEE 802.1D, IEEE 802.1Q, and IEEE 802.1F.  6.2 Compatibility  IEEE 802 defines a family of standards. All standards shall be in conformance with the IEEE 802.1 Architecture, Management and Interworking documents as follows: 802. Overview and Architecture, 802.1D, 802.1Q and parts of 802.1f. If any variances in conformance emerge, they shall be thoroughly disclosed and reviewed with 802. Each standard in the IEEE 802 family of standards shall include a definition of managed objects, which are compatible with systems management standards.  ESS Mesh specifies one possible Wireless Distribution System (WDS) that behaves in every respect as an IEEE 802.11 Infrastructure Mode network. As such, it is entirely compatible with the IEEE 802.11 architecture and, by inference, compatible with the IEEE 802 architecture, including IEEE 802.1D, IEEE 802.1Q, and IEEE 802.1F.

4. doc.: IEEE 802.11-04/0981r1 TGs Reference Architecture Considerations September 6, 2004 Tricci So & W. Steven Conner.Slide 4 Why Should We Start with IEEE Std. 802.1D?

5. doc.: IEEE 802.11-04/0981r1 TGs Reference Architecture Considerations September 6, 2004 Tricci So & W. Steven Conner.Slide 5 What is IEEE 802.1D MAC Bridge? IEEE Std 802.1D-2004, 1.1: IEEE 802 Local Area Networks (or LANs; see 3.4) of all types can be connected together using MAC Bridges. The Bridged Local Area Network created allows the Interconnection of stations as if they were attached to a single LAN, even if they are attached to separate LANs each with its own independent MAC. A MAC Bridge operates below the MAC Service Boundary, and is transparent to protocols operating above this boundary, in the Logical Link Control (LLC) sublayer or Network Layer (ISO/IEC 7498-1:1994)..... IEEE Std 802.1D-2004, 1.1: IEEE 802 Local Area Networks (or LANs; see 3.4) of all types can be connected together using MAC Bridges. The Bridged Local Area Network created allows the Interconnection of stations as if they were attached to a single LAN, even if they are attached to separate LANs each with its own independent MAC. A MAC Bridge operates below the MAC Service Boundary, and is transparent to protocols operating above this boundary, in the Logical Link Control (LLC) sublayer or Network Layer (ISO/IEC 7498-1:1994)..... IEEE Std 802.1D-2004, Figure 7-3: Bridge Architecture (ISS)

6. doc.: IEEE 802.11-04/0981r1 TGs Reference Architecture Considerations September 6, 2004 Tricci So & W. Steven Conner.Slide 6 What does IEEE 802.11 Say About DS & ESS? IEEE Std 802.11-1999, 3.20 & 3.25: 3.20 distribution system (DS): A system used to interconnect a set of basic service sets (BSSs) and integrated local area networks (LANs) to create an extended service set (ESS). 3.25 extended service set (ESS): A set of one or more interconnected basic service sets (BSSs) and integrated local area networks (LANs) that appears as a single BSS to the logical link control layer at any station associated with one of those BSSs. IEEE Std 802.11-1999, 3.20 & 3.25: 3.20 distribution system (DS): A system used to interconnect a set of basic service sets (BSSs) and integrated local area networks (LANs) to create an extended service set (ESS). 3.25 extended service set (ESS): A set of one or more interconnected basic service sets (BSSs) and integrated local area networks (LANs) that appears as a single BSS to the logical link control layer at any station associated with one of those BSSs. IEEE Std 802.11-1999, Figure 3: Extended Service Set

7. doc.: IEEE 802.11-04/0981r1 TGs Reference Architecture Considerations September 6, 2004 Tricci So & W. Steven Conner.Slide 7 What “More” STD 802.11 Spec Says?  5.1.1.4 Interaction with other IEEE 802 Layers IEEE 802.11 is required to appear to higher layers [logical link control (LLC)] as a current style IEEE 802 LAN. This requires that the IEEE 802.11 network handle station mobility within the MAC sublayer. To meet reliability assumptions (that LLC makes about lower layers), it is necessary for IEEE 802.11 to incorporate functionality that is untraditional for MAC sublayers.  5.1.1.4 Interaction with other IEEE 802 Layers IEEE 802.11 is required to appear to higher layers [logical link control (LLC)] as a current style IEEE 802 LAN. This requires that the IEEE 802.11 network handle station mobility within the MAC sublayer. To meet reliability assumptions (that LLC makes about lower layers), it is necessary for IEEE 802.11 to incorporate functionality that is untraditional for MAC sublayers. IEEE Std 802.1D-2004, Figure 7-3: Bridge Architecture (ISS)

8. doc.: IEEE 802.11-04/0981r1 TGs Reference Architecture Considerations September 6, 2004 Tricci So & W. Steven Conner.Slide 8 Do We See Any Similarity Between MAC Bridge & ESS Mesh? MAC LLC MACMAC RELAY MAC LLC MAC Service User Provider MAC Bridge Reference IEEE Std 802.1D-2004, section 6. MAC Bridges interconnect the separate IEEE 802 LANs that compose a Bridged Local Area Network by relaying and filtering frames between the separate MACs of the bridged LANs.... IEEE Std 802.1D-2004, section 6. MAC Bridges interconnect the separate IEEE 802 LANs that compose a Bridged Local Area Network by relaying and filtering frames between the separate MACs of the bridged LANs.... 802.11sMesh Reference obtained from Std. 802.1D Figure 6-1. Reference obtained from Std. 802.1D Figure 6-1. WirelessDistributedSystem 802.11LAN WiredDistributedSystem

9. doc.: IEEE 802.11-04/0981r1 TGs Reference Architecture Considerations September 6, 2004 Tricci So & W. Steven Conner.Slide 9 What Does IEEE 802 Say About 802.1D Support Requirements from 802.11? IEEE Std. 802.1D-2004, 6.5 Support of the Internal Sublayer Service (ISS) by specific MAC procedures... 6.5.4 Support by IEEE Std 802.11 (Wireless LANs) A Bridge to an IEEE 802.11 LAN shall connect to an IEEE 802.11 Portal, which in turn connects to an IEEE 802.11 Distribution System. For the purpose of bridging, the service interface presented at the Portal is identical to the service interface presented at the IEEE 802.11 MAC SAP. An instance of an 8802-11 Distribution System can be implemented from IEEE 802 LAN components. IEEE 802.11 STAs attach to the Distribution System via an IEEE 802.11 Access Point..... On receipt of an M_UNITDATA.request primitive, the portal constructs a MAC Service Data Unit and passes it to the MAC Data service for transmission using the parameters supplied... On receipt of a valid MAC Service Data Unit, the portal generates an M_UNITDATA.indication primitive with parameter values derived from the frame fields.... On the data plane, 802.11 Interfacing with other 802 LANs Internal Sublayer Service (ISS) through the support of Internal Sublayer Service (ISS) On the data plane, 802.11 Interfacing with other 802 LANs Internal Sublayer Service (ISS) through the support of Internal Sublayer Service (ISS)

10. doc.: IEEE 802.11-04/0981r1 TGs Reference Architecture Considerations September 6, 2004 Tricci So & W. Steven Conner.Slide 10 What Is 802.1D Internal Sublayer Service? IEEE Std. 802.1D-2004, 6.4 Internal Sublayer Service provided within the MAC Bridge... The Internal Sublayer Service (ISS) provided by a MAC entity to the MAC Relay Entity within a Bridge is that provided by the individual MAC for the LAN Port. This observes the appropriate MAC procedures and protocol for the LAN to which it attaches. No control frames, i.e., frames that do not convey MAC user data, are forwarded on any LAN other than that on which they originated. The Internal Sublayer Service is derived from the MAC Service defined by ISO/IEC 15802-1 by augmenting that specification with elements necessary to the performance of the relay function..... Two parameters are added to the list of parameters associated with the MA_UNITDATA.request and MA-UNITDATA.indication primitives defined by ISO/IEC 15802-1. These are frame_type and frame_check_sequence. The definition of the Internal Sublayer Service does NOT add any new service primitives to those defined by the LAN MAC Service Definition.

11. doc.: IEEE 802.11-04/0981r1 TGs Reference Architecture Considerations September 6, 2004 Tricci So & W. Steven Conner.Slide 11 ISS Service Mappings for 802.11 MAC M_UNITDATA.request(frame_type, mac_action, DA, SA, Routing Information, MSDU, user_priority, access_priority, FCS) M_UNITDATA.indication(frame_type, mac_action, DA, SA, Routing Information, MSDU, user_priority, access_priority, FCS) DA SA MSDU FCS 802.11 Frame Fields user_data_frame Request_with_no_response Fixed Mapping Fixed Mapping Refer to IEEE Std 802.1D-2004: 6.5.4 Support by IEEE Std 802.11 (Wireless LAN) To Be Determined

12. doc.: IEEE 802.11-04/0981r1 TGs Reference Architecture Considerations September 6, 2004 Tricci So & W. Steven Conner.Slide 12 What Does 802.1D MAC Bridge Look Like in term of 802.3 and 802.11 Protocol Stack? LLC MAC Service (ISS) Portal ISS MAC Relay Entity 802.1D Clause 6.5.1 802.1D Clause 6.5.4 802.3802.11 802.3 LAN 802.11 LAN The MAC Sublayer in an 802.1D MAC Bridge IEEE 802.1D 6.5.4: A Bridge to an IEEE 802.11 LAN shall connect to an IEEE 802.11 Portal, which in turn connects to an IEEE 802.11 Distribution System. For the purpose of bridging, the service interface presented at the Portal is identical to the service interface presented at the IEEE 802.11 MAC SAP. An instance of an 8802-11 Distribution System can be implemented from IEEE 802 LAN components. IEEE 802.11 STAs attach to the Distribution System via an IEEE 802.11 Access Point IEEE 802.1D 6.5.4: A Bridge to an IEEE 802.11 LAN shall connect to an IEEE 802.11 Portal, which in turn connects to an IEEE 802.11 Distribution System. For the purpose of bridging, the service interface presented at the Portal is identical to the service interface presented at the IEEE 802.11 MAC SAP. An instance of an 8802-11 Distribution System can be implemented from IEEE 802 LAN components. IEEE 802.11 STAs attach to the Distribution System via an IEEE 802.11 Access Point MAC Independent Functions MAC Dependent Functions MAC Specific Functions 802.11 Portal is part of the ISS Refer to IEEE Std 802.1D Figure 7-3 Bridge Architecture MAC Service Part of the Distribution System (DS)

13. doc.: IEEE 802.11-04/0981r1 TGs Reference Architecture Considerations September 6, 2004 Tricci So & W. Steven Conner.Slide 13 What Does 802.11 Say about Portal and IEEE 802 LAN-based DS? IEEE Std 802.11 5.2.4: Integration with wired LANs All data from non-IEEE 802.11 LANs enter the IEEE 802.11 architecture via a portal. The portal provides logical integration between the IEEE 802.11 architecture and existing wired LANs. It is possible for one device to offer both the functions of an AP and a portal; this could be the case when a DS is implemented from IEEE 802 LAN components. IEEE Std 802.11 5.2.4: Integration with wired LANs All data from non-IEEE 802.11 LANs enter the IEEE 802.11 architecture via a portal. The portal provides logical integration between the IEEE 802.11 architecture and existing wired LANs. It is possible for one device to offer both the functions of an AP and a portal; this could be the case when a DS is implemented from IEEE 802 LAN components. LLC MAC Service ISS (Portal) ISS MAC Relay Entity 802.1D Clause 6.5.1 802.1D Clause 6.5.4 802.3802.11 802.3 LAN 802.11 LAN The MAC Sublayer in an 802.1D MAC Bridge MAC Independent Functions MAC Dependent Functions MAC Specific Functions MAC Service Part of the Distribution System (DS) IEEE 802.1D and 802.11 Specifications are very consistent with the entire 802 network architecture today... IEEE 802.1D and 802.11 Specifications are very consistent with the entire 802 network architecture today...

14. doc.: IEEE 802.11-04/0981r1 TGs Reference Architecture Considerations September 6, 2004 Tricci So & W. Steven Conner.Slide 14 802.11 LAN (BSSs) - ESS 802.11s ESS Mesh Data Plane Reference Architecture Considerations 802.11 ESS Mesh 802.11 ESS Mesh Access I/F MeshI/F Mesh AP M2 M1 M2 M3 MAC LLC MESHRELAY MACMACMACMACMACMAC Access I/F MeshI/F Mesh AP M3 MeshI/F Mesh Point M1 MAC LLC 802.11 LAN 802.11 ESS Mesh 802.11 ESS Mesh Network 802.11 ESS Mesh Data Plane Reference Architecture MESHRELAYMESHRELAY Note: The interface above represents a “logical” configuration and DOES NOT refer to a “physical” configuration, i.e. the configuration is agnostic to single or multiple radios mesh AP system.