Transcript PPT Version

IPv6 over 802.16’s IPv6 Convergence Sublayer
draft-madanapalli-ipv6-over-802.16-ipv6cs-00
Syam Madanapalli
Basavaraj Patil
Erik Nordmark
JinHyeock Choi
Soohong D. Park
IETF 66 – Montreal
9-14 July 2006
Agenda
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Introduction to WiMAX Network Architecture
IPv6 over 802.16’s IPv6 CS – Solution
Scope of the draft
Way Forward
WiMAX Network Architecture
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R1
ASN GW - Omniscient AR
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MS 1
BS 1
R6
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ASN
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MAC Transport Connection
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R3
MS 2
ASN GW
MS 3
BS 2
MS 4
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Knows about all nodes attached
to itself
Only one AR at any given time
Always exists between MS and
ASN GW
 802.16 MAC connection
between MS and BS
 R6 GRE tunnel between BS
and ASN GW
Initial Service Flow
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Created as soon as
completion of Network
Entry
Can be used for
autoconfiguration
Proposed Solution
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R1
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Link
MS 1
BS 1
R6
ASN
R3
MS 2
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ASN GW
MS 3
MS 4
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
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BS 2
IP Link
ASN GW is the first-hop AR
Prefix Assignment
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One or more prefixes are
shared among the MSs
Neighbor Discovery …
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Router Discovery
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Periodic RAs
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Send them in unicast manner
MaxRtrAdvInterval > 1800 sec.
Prefix Assignment
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Send an unsolicited RA as soon as the initial 802.16 transport
connection has been established
Or just do RS/RA
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
Next-Hop
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Always the ASN GW for an MS
An intelligent implementations need not perform this
No direct communication is allowed between two MSs
Neighbor Discovery
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Address Resolution
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NUD
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Required because an MS may have more than one IPv6 address
Can be performed as specified in 2461bis
Redirect
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Not required
But the existing implementations may attempt address resolution
 AR just ignores the NS
 After no response, MS sends the packet to the AR, the default
router
ASN GW should not redirect for the packets destined to the same IP
Link
Hop Count
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Should not be decremented for the on-link communication
Address Autoconfiguration
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Interface Identifier generation
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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
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MS behavior is as specified in 2462bis
DAD is performed using Relay DAD
Relay DAD
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ASN GW Maintains Address Cache
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Relays the DAD Probe if there is a match in the address
cache for the destination solicited node multicast address
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List of IPv6 addresses that are currently in use including solicitednode multicast addresses.
Learns the addresses from DAD NS, if the address is not duplicate
Learns the Solicited-Node Multicast Addresses from MLD Join
MS responds to the DAD Probe if the address is duplicate
Address Cache entries expire when
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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
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Address Cache overflow
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Loss of DAD Probe
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AR should limit the no. of addresses an MS can have at any
given time
Do we need to dealt with it?
Tunnel between BS and AR
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Should be per MS for IP CS
Scope of the document
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Current scope covers only WiMAX Network
Architecture
Should 16ng consider other deployment
scenarios?
Should this document cover the other scenarios?
Or WG allows writing another draft?
Way Forward
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Include other deployment scenarios?
Accept as WG document?