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
Introduction to WiMAX Network Architecture
IPv6 over 802.16’s IPv6 CS – Solution
Scope of the draft
Way Forward
WiMAX Network Architecture
R1
ASN GW - Omniscient AR
MS 1
BS 1
R6
ASN
MAC Transport Connection
R3
MS 2
ASN GW
MS 3
BS 2
MS 4
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
Created as soon as
completion of Network
Entry
Can be used for
autoconfiguration
Proposed Solution
R1
Link
MS 1
BS 1
R6
ASN
R3
MS 2
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
BS 2
IP Link
ASN GW is the first-hop AR
Prefix Assignment
One or more prefixes are
shared among the MSs
Neighbor Discovery …
Router Discovery
Periodic RAs
Send them in unicast manner
MaxRtrAdvInterval > 1800 sec.
Prefix Assignment
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
Always the ASN GW for an MS
An intelligent implementations need not perform this
No direct communication is allowed between two MSs
Neighbor Discovery
Address Resolution
NUD
Required because an MS may have more than one IPv6 address
Can be performed as specified in 2461bis
Redirect
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
Should not be decremented for the on-link communication
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
DAD is performed using Relay DAD
Relay DAD
ASN GW Maintains Address Cache
Relays the DAD Probe if there is a match in the address
cache for the destination solicited node multicast address
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
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
Loss of DAD Probe
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
Should be per MS for IP CS
Scope of the document
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
Include other deployment scenarios?
Accept as WG document?