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Mobile IPv6 Performance & Its Optimization. Youn-Hee Han yhhan@kut.ac.kr Korea University of Technology and Education Internet Computing Laboratory http://icl.kut.ac.kr. Why IPv6 and Mobile IPv6. MIPv6 Sequence Chart. Layer 2 Connection Completed. AR. MH. HA. CN. New coa
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Mobile IPv6 Performance & Its Optimization Youn-Hee Han yhhan@kut.ac.kr Korea University of Technology and EducationInternet Computing Laboratory http://icl.kut.ac.kr
Why IPv6 and Mobile IPv6 MIPv6 Sequence Chart Layer 2 Connection Completed AR MH HA CN New coa configuration AP RS (1) RA (2) BU Establish tunnel / update routing table (3) BACK Establish tunnel Forward according to RT tcp packets tcp packets ack packets ack packets HoTI HoTI CoTI HoT HoT (3)’ CoT BU BACK tcp packets ack packets (1) Movement Detection, (2) CoA Configuration, (3) Registration (Binding Update)
Why IPv6 and Mobile IPv6 MIPv6 Timing Model
Handoff Time L2 Handoff Time L3 Handoff Time Movement Detection IP address configuration RR & BU 30 - 400 ms 3000 - 5000 ms for MIPv6 without optimization method.
Movement Detection • 출처 • Y.-H. Han and S.-H. Hwang, "Movement Detection Analysis in Mobile IPv6," IEEE Communication Letters, Vol.10, No.1, pp.59-61, January 2006. • A movement hint by link-up event
Movement Detection • A movement hint comes from two sources: • 1) the receipt of new unsolicited RAs
Movement Detection • The average period to receive a new unsolicited RA
Movement Detection • A movement hint comes from two sources: • 2) the awareness of the existing RA’s
Movement Detection • The average period to notice the existing RA’s absence
Movement Detection • Reachability of a new access router
Movement Detection • Reachability of a new access router
Movement Detection • Unreachability of the previous access router
Movement Detection • Total latency of MD process
CoA Configuration & DAD • 출처 • Y.-H. Han, J.-H. Choi, and S.-H. Hwang, "Reactive Handover Optimization in IPv6-Based Mobile Networks," IEEE JSAC - Special Issue on Mobile Routers and Network Mobility, Vol.24, No.9, pp.1758- 1772, September 2006. • DAD latency
MD Optimization http://tools.ietf.org/id/draft-ietf-dna-frd-02.txt L2 Handoff Time L3 Handoff Time Movement Detection IP address configuration RR & BU 30 - 400 ms 3000 - 5000 ms for MIPv6 without optimization method. An optimization scheme :Fast Router Discovery (FRD)
MN Current MD Procedure 1. MN arrives at a new network. Internet AR AP
MN Current MD Procedure 2. MN sends Association Request (802.11b) to AP with its MAC address. Internet AR AP MAC addr
MN Current MD Procedure 2. MN sends Association Request (802.11b) to AP with its MAC address. Internet AR AP MAC addr
MN Current MD Procedure Internet 3. AP sends Association Response and makes an associates with MN. AR AP AR
MN Current MD Procedure Internet 3. AP sends Association Response and makes an associates with MN. AR AP AR
MN Current MD Procedure Internet 4.MN sends RS (Router Solicitation) if L2 provides information. AR AP RS
MN Current MD Procedure Internet 4.MN sends RS (Router Solicitation) if L2 provides information. AR AP RS
MN Current MD Procedure Internet 4.MN sends RS (Router Solicitation) if L2 provides information. RS AR AP
MN Current MD Procedure Internet 4.MN sends RS (Router Solicitation) if L2 provides information. RA AR 5. AR sends RA. AP
MN Current MD Procedure Internet 4.MN sends RS (Router Solicitation) if L2 provides information. AR 5. AR sends RA. RA AP
MN Current MD Procedure Internet 4.MN sends RS (Router Solicitation) if L2 provides information. AR 5. AR sends RA. AP 6. MN knows its new AR after receiving RA. RA
MN FRD Procedure 0. AP caches RA. Internet AR RA AP
MN FRD Procedure 0. AP caches RA. 1. MN arrives at a new network. Internet 2. MN sends Association Request with its MAC addr. AR RA AP
MN FRD Procedure Internet AR RA AP MAC addr
MN FRD Procedure Internet 3. AP associates with MN with Association Response. AR RA AP MAC addr
FRD Procedure Internet AR 4. AP generates L2 notification frame using 1) stored RA & 2) MAC addr from association request. AP RA MAC addr MN
FRD Procedure Internet AR AP 5. AP sends MN L2 notification frame containing RA. RA MAC addr MN
FRD Procedure Internet AR AP 6. MN knows its subnet from received RA. RA MN
1. MN arrives and sends Association Request 2. AP receives Association Request. 4. MN receives Association Response and association is made. 8. MN receives RA and discovers new subnet. 5. MN sends RS after Random delay. 6. AR receives RS 7. AR sends RAafter Random delay 3. AP sends Association Response. MD Delay for Current MD AR AP MN
5. MN receives RA and discovers new subnet. 4. AP send stored RA. 1. MN arrives and sends Association Request 2. AP receives Association Request. 4. MN receives Association Response and association is made. 3. AP sends Association Response MD Delay for FRD AR AP MN Roughly processing time to generate proxy RA, less than 1 ms.
DAD Optimization L2 Handoff Time L3 Handoff Time Movement Detection IP address configuration RR & BU 30 - 400 ms 3000 - 5000 ms for MIPv6 without optimization method. An optimization scheme :Optimistic DAD (oDAD) and Advance DAD (aDAD)
Original DAD Procedure • Layer 3 Handover Delay in MIPv6 using RFC2461 DAD • IID is obtained from the interface hardware or generated randomly. • Generate an address and mark it “tentative address” • Join solicited-node multicast group for the address • Send NS • Wait RetransTimer (default:1000) ms • This solicit-and-wait process is repeated DupAddrDetectTransmits (default:1) times Send NS Send BU move to new link 1000ms Get New Network Prefix Duplicate Address Detection BU & BAckExchange Get Layer 2Connectivity
A Stateless Proposal : Optimistic DAD(RFC 4429) • The odds of IPv6 address collision are very low • Allow communication to be established over a tentative address, while attempting to minimize disruption in the case of collision. • With a tentative address, NA is sent withO flag = 0. • If a neighbor node already has a NC entry for that address, the NA should be ignored. • NSs cannot be sent while an address is tentative • traffic for unknown neighbors is redirected via the router. P(2^62,20)=< 7.8 e-17 P(2^62,100)=< 2.1 e-15 P(2^62,500)=< 5.4 e-14 P(2^62,1000)=< 2.2 e-13 P(2^62,5000)=< 5.4 e-12 The odds of IPv6 address collision can be calculated with ‘the Birthday Problem’(draft-soto-mobileip-random-iids-00.txt)
A Stateful Proposal : Advance DAD(draft-han-mobileip-adad-01.txt… & other papers) • Each AR (may be involved in Fast Handover) maintains a ‘Duplication-free CoA Pool‘, and allocates the one into MN ASAP. • each address in the pool is in advance generated randomly and tested for its uniqueness using RFC 2461 DAD • The goals of Passive-Proxy-ND? • Guarantee the uniqueness of address in the pool • DO NOT disturb the address configuration of MNs using RFC2461 DAD [Passive-proxy-ND] Rule 1 : Do not reveal voluntarily. Rule 2 : Do not reply. And, delete it. AR AR AR PoolAddr#1=a : Addr#n=z PoolAddr#1=a : Addr#n=z PoolAddr#1= : Addr#n=z NS(target=a) unsolicited NA(target=a) Do not reply Y.-H. Han and S.-H. Hwang, "Care-of Address Provisioning for Efficient IPv6 Mobility Support", Elsevier Computer Communications, Vol.29, No.9, pp.1422-1432, 2006.
Internet AR1 AR2 MN AP1 AP2 Current DAD 1. IID is obtained from the interface hardware or generated randomly. 2. Generate an address and make it “tentative address” 3. Join solicited-node multicast group for the address 4. Send NS 5. Wait RetransTimer (default: 1000) ms 6. This solicit-and-wait process is repeated DupAddDetecTransmit (default: 1) times.
MN aDAD Procedure 0. AR caches DAD-free Addresses Internet DAD free Addr AR AP
MN aDAD Procedure 0. AR caches DAD-free Addresses 1. MN arrives at a new network. Internet 2. MN makes a new L2 connection and completes MD. 3.MN sends RS (Router Solicitation) asking DAD-free Address. DAD free Addr AR AP RS
MN aDAD Procedure 0. AR caches DAD-free Addresses 1. MN arrives at a new network. Internet 2. MN makes a new L2 connection and completes MD. 3.MN sends RS (Router Solicitation) asking DAD-free Address. DAD free Addr AR 4.AR makes RA containing DAD-free Addr in option RS AP
RA DAD free Addr MN aDAD Procedure 0. AR caches DAD-free Addresses 1. MN arrives at a new network. Internet 2. MN makes a new L2 connection and completes MD. 3.MN sends RS (Router Solicitation) asking DAD-free Address. AR 4.AR makes RA containing DAD-free Addr in option 5.AR sends RA containing DAD-free Addr in option to MN. AP
RA DAD free Addr MN aDAD Procedure 0. AR caches DAD-free Addresses 1. MN arrives at a new network. Internet 2. MN makes a new L2 connection and completes MD. 3.MN sends RS (Router Solicitation) asking DAD free Address. AR 4.AR makes RA containing DAD-free Addr in option 5.AR sends RA containing DAD-free Addr in option to MN. AP 6.MN extracts DAD-free Addr from RA and forms a new CoA.
1. MNfinishes MD and sends NS. DAD Delay for Current DAD AR MN 2. If 1000 ms has passed without NA, MN assumes its address is unique and ends DAD. Roughly 1000ms
1. MNfinishes MD and sends RS asking DAD free Addr. DAD Delay for aDAD AR MN 2. AR receives RS. 5. MN receives RA with DAD free Addr. 3. AR makes RA with DAD free Addr. 6. MN extracts DAD free Addr from RA and forms new CoA. 4. AR sends RA with DAD free Addr to MN. Roughly the propagation delay between MN and AR, less than 2ms
Registation (BU) Optimization L2 Handoff Time L3 Handoff Time Movement Detection IP address configuration RR & BU 30 - 400 ms 3000 - 5000 ms for MIPv6 without optimization method. An optimization scheme :Hierarchical Mobile IPv6 (HMIPv6)
Localized Mobility Management • Problems in MIPv6 • Macro Mobility • Vulnerable to handover delay and packet loss. • If the rate of movement increase, the number of BUs increase • BU RTT of MN HA or MN CN : 300 – 500 ms • Signaling Overhead • Principles of Localized Mobility Management • Extensions to MIPv6 • Minimize frequent BUs to its HA and CNs • Introduce Localized Mobility Management Agents (LMA) into the visited domain (it is similar to HA) • BU Signaling is localized in a most time • LCoA & RCoA • Implementation Example : HMIPv6 (INRIA France)
HMIPv6 Patent RFC 4140, Aug 2005