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IPv6 over 802.16 Solution Framework. syam@samsung.com jinchoe@samsung.com basavaraj.patil@nokia.com. IETF 65 – Dallas, TX 19-24 March 2006. ASN GW - Omniscient AR Knows about all nodes attached to itself Only one AR at any given time Transport Connection (Not UDP/TCP Connection)
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IPv6 over 802.16Solution Framework syam@samsung.com jinchoe@samsung.com basavaraj.patil@nokia.com IETF 65 – Dallas, TX 19-24 March 2006
ASN GW - Omniscient AR Knows about all nodes attached to itself Only one AR at any given time Transport Connection (Not UDP/TCP Connection) Always exists between MS and ASN GW 802.16 MAC connection between MS and BS R6 GRE tunnel between BS and ASN GW WiMAX Network Architecture R1 MS 1 ASN R6 BS 1 MS 2 R3 ASNGW MS 3 BS 2 MS 4
Design Tenets • No change to existing IPv6 protocols and standards defined in IETF • No changes in host side implementation • should work with any IPv6 spec. compliant stack • Minimal Changes are permitted in Network Side entities
IP Link The ASN GW, Multiple BSs attached to the ASN GW and all MS attached to these BSs are all on same IP Link Access Router ASN GW is the first-hop AR Prefix Assignment One or more prefixes are shared among the MSs Proposed Solution Link R1 MS 1 ASN R6 BS 1 MS 2 R3 ASNGW MS 3 BS 2 MS 4
Neighbor Discovery … • Router Discovery • Send an unsolicited RA as soon as the initial 802.16 transport connection has been established • Or just do RS/RA • Periodic RAs • Optional • Send them in unicast manner (either with unicast or multicast destination address) • Operator can disable them • Prefix Assignment • One or more prefixes are shared among the nodes on the link • Prefixes are advertised with on-link flag (L-bit) reset and autonomous address-configuration flag (A-bit) set
Neighbor Discovery • Next-Hop • Always the ASN GW for an MS • No direct communication is allowed between two MSs • Address Resolution • Not required • But the existing implementations may attempt address resolution • Either the local host driver or the ASN GW can proxy for this • NUD • Required because an MS may have more than one IPv6 address • Can be performed as specified in 2461bis
Address Autoconfiguration • Interface Identifier generation • Generate the IID from MS’s 48-bit MAC address as per RFC2464 • Optionally, it is allowed to use Privacy Extensions as specified in RFC 3041 • Duplicate Address Detection • MS behavior is as specified in 2462bis • ASN GW proxies for other MSs to defend the address in case of duplicate • Call it as Proxy DAD • ASN GW maintains Address Cache containing all the addresses that are in use within its IP link
Proxy DAD • ASN GW Maintains Address Cache • Learns the addresses from DAD NS, if the address is not duplicate • Defends the addresses in the Address Cache in case an MS generates a duplicate address • Checking for IID matching may be considered as duplicate • Address Cache entries expire when • Prefix life time expires • MS or another entity deregisters explicitly • R6 GRE tunnel for the MS is deleted • NS/NA exchange with longer intervals • Issues • Address Cache overflow • ASN GW can limit the no. of addresses an MS can have at a given time