Transmission of IP Packets over Ethernet over IEEE802.16 draft-riegel-16ng-ip-over-eth-over-80216-00

1. Transmission of IP Packets over Ethernet over IEEE802.16draft-riegel-16ng-ip-over-eth-over-80216-00 Max Riegel <maximilian.riegel@siemens.com> 2006-07-07

2. Introduction • Goal of this presentation • Present draft-riegel-16ng-ip-over-eth-over-80216-00.txt • Introduce topic and particular issues with Ethernet over IEEE802.16 • Provide background information on IEEE802.16 link behavior • Outline solution approaches • Promote contributions from others • Status of draft-riegel-16ng-ip-over-eth-over-80216-00.txt • Initial I-D • Provides outline and hints, how the solution may look like • IPv4 solution based on results out of WiMAX NWG • Lots of material still missing 16ng@IETF-66 IEEE802.16 Fixed/nomadic deployment (Max Riegel) Page 2

3. IP works fine over Ethernet Internet • RFC 894 defines transmission of IPv4 packets over Ethernet • RFC 826 recommends the use of ARP for address resolution • RFC2464 specifies the transmission of IPv6 packets over Ethernet • Today most Ethernets are (bridged) switched LANs with point-to-point links between Switch and Host • No issues when there is sufficient bandwidth and power • Usually the case for wired Ethernets • Wireless issues: shared transmission resource and limited power. • Power issue may even be more critical than scarce transmission resource 16ng@IETF-66 IEEE802.16 Fixed/nomadic deployment (Max Riegel) Page 3

4. Protocol Layering of the IEEE 802.16 Standard • Physical Layer, MAC Common Part Sublayer and Management/Control Plane are agnostic to user payload (CS type) • Standard accommodates multiple instantiations of CS types • Classification is specific to particular CS type • e.g. for IPoETH-CS, 14-18 bytes of additional header information must be parsed per packet. 16ng@IETF-66 IEEE802.16 Fixed/nomadic deployment (Max Riegel) Page 4

5. Convergence SublayerClassification & Encapsulation • Packet-handling in the base station is done based on information in the packet header Classification based on header information Encapsulation and forwarding 16ng@IETF-66 IEEE802.16 Fixed/nomadic deployment (Max Riegel) Page 5

6. CS SAP CS SAP CS SAP Classifier Classifier Classifier CID#1 CID#3 CID#5 PHS (opt.) PHS (opt.) PHS (opt.) MAC SAP MAC SAP MAC SAP MAC Common Part Sublayer (MAC CPS) MAC Common Part Sublayer (MAC CPS) MAC Common Part Sublayer (MAC CPS) Privacy Sublayer Privacy Sublayer Privacy Sublayer PHY SAP PHY SAP PHY SAP Physical Layer (PHY) Physical Layer (PHY) Physical Layer (PHY) The IEEE802.16 Link Model APPL APPL APPL • IEEE802.16 provides point-to-point links between the BS and MS • No direct communication between terminals possible • Fits well into switched Ethernet model IEEE802.16/802.16e Data/Control Plane CS SAP Service Specific Convergence Sublayer (CS) CID#2 CID#4 CID#6 Classifier PHS (opt.) MAC SAP MAC MAC Common Part Sublayer (MAC CPS) Privacy Sublayer Radio PHY SAP Physical Layer (PHY) PHY BS MS MS MS 16ng@IETF-66 IEEE802.16 Fixed/nomadic deployment (Max Riegel) Page 6

7. CS SAP CS SAP CS SAP Classifier Classifier Classifier CID#1 CID#3 CID#5 PHS (opt.) PHS (opt.) PHS (opt.) MAC SAP MAC SAP MAC SAP MAC Common Part Sublayer (MAC CPS) MAC Common Part Sublayer (MAC CPS) MAC Common Part Sublayer (MAC CPS) Privacy Sublayer Privacy Sublayer Privacy Sublayer PHY SAP PHY SAP PHY SAP Physical Layer (PHY) Physical Layer (PHY) Physical Layer (PHY) Switched Ethernet link model for IEEE802.16 APPL APPL APPL • Switch in basestation broadcasts packets to all MSs, if destination MAC address is not known in the switch • Waste of radio resource • All terminals have to wake up to process broadcast packet IEEE802.16/802.16e Data/Control Plane CS SAP Service Specific Convergence Sublayer (CS) CID#2 CID#4 CID#6 Classifier PHS (opt.) MAC SAP MAC MAC Common Part Sublayer (MAC CPS) Privacy Sublayer Radio PHY SAP Physical Layer (PHY) PHY BS MS MS MS 16ng@IETF-66 IEEE802.16 Fixed/nomadic deployment (Max Riegel) Page 7

8. CS SAP CS SAP CS SAP Classifier Classifier Classifier CID#1 CID#3 CID#5 PHS (opt.) PHS (opt.) PHS (opt.) MAC SAP MAC SAP MAC SAP MAC Common Part Sublayer (MAC CPS) MAC Common Part Sublayer (MAC CPS) MAC Common Part Sublayer (MAC CPS) Privacy Sublayer Privacy Sublayer Privacy Sublayer PHY SAP PHY SAP PHY SAP Physical Layer (PHY) Physical Layer (PHY) Physical Layer (PHY) Enhanced Ethernet link model for IEEE802.16 APPL APPL APPL • Dedicated switch functions prevent the ‘unnecessary’ transmission of ETH frames over the air • Response to broadcast and multicast requests on behalf of the MSs • Must learn about the MAC & IP addresses of the MSs IEEE802.16/802.16e Data/Control Plane CS SAP Service Specific Convergence Sublayer (CS) CID#2 CID#4 CID#6 Classifier PHS (opt.) MAC SAP MAC MAC Common Part Sublayer (MAC CPS) Privacy Sublayer Radio PHY SAP Physical Layer (PHY) PHY BS MS MS MS 16ng@IETF-66 IEEE802.16 Fixed/nomadic deployment (Max Riegel) Page 8

9. IPv4 specific behavior of the bridging function • Proxy ARP function • The BS SHALL support Proxy-ARP. • The BS SHALL have the ability to enable or disable Proxy ARP. If Proxy ARP is disabled, the ARP Proxy Agent shall pass all ARP packets without discrimination or modification using Standard Learned Bridging. • Upon receiving an ARP Request from a network side interface, the ARP Proxy Agent shall unicast an ARP Response back to that interface, provided that the target address matches an entry in the Proxy ARP table. If no match is found in the Proxy ARP table, the ARP Proxy Agent SHALL support silently discarding the Request or flooding the Request to all radio connection interfaces based upon configuration option. • The ARP Proxy Agent shall pass all ARP Response packets without discrimination or modification using Standard Learned Bridging. Upon receiving an ARP Request from an radio connection interface, the ARP Proxy Agent shall unicast an ARP Response back to the interface provided that the target address matches an entry in the Proxy ARP table. Otherwise, the ARP Proxy Agent shall flood the Request to all network side interfaces. • The ARP Proxy Agent shall silently discard any received self-ARP Requests. Those are requests for a target IP address, that when queried in the Proxy ARP table results in a response MAC equal to the Request's source MAC address. • The ARP Proxy Agent shall issue a gratuitous ARP on the network side interfaces for any new addition to the Proxy ARP table. An unsolicited broadcast ARP Response constitutes a gratuitous ARP. The Proxy ARP table MAY be established out of other IPv4 specific information available in the BS, e.g. DHCP Proxy or MIPv4 FA. The particular procedures are implementation dependent. • Information for the Proxy ARP Table MAY be transferred during handover of a mobile IEEE802.16e station to the target BS. The particular protocol for transfer of information for the Learned Bridge Table is out of scope of this specification. 16ng@IETF-66 IEEE802.16 Fixed/nomadic deployment (Max Riegel) Page 9

10. IPv6 specific behavior of the bridging function • t.b.f. 16ng@IETF-66 IEEE802.16 Fixed/nomadic deployment (Max Riegel) Page 10

11. Conclusion • Current specification makes no use of MBS feature of IEEE802.16 MAC • MBS may not provide essential benefits for supporting multicast • Power consumption issue may be more important than radio resource issue • Proxy functions in bridge at BS may gain more than enhancements to the multicast behavior of IEEE802.16 • Need for context transfer between proxy tables during handover • Learned table entries may efficiently be reused by the target BS • Open: context transfer protocol 16ng@IETF-66 IEEE802.16 Fixed/nomadic deployment (Max Riegel) Page 11

12. Questions & Comments • ? 16ng@IETF-66 IEEE802.16 Fixed/nomadic deployment (Max Riegel) Page 12