DMAP: A Scalable and Efficient Integrated Mobility and Service Management Scheme for Mobile IPv6 Systems

Ing-Ray Chen, Weiping He, and Baoshan Gu

Paper Presented by: Vidhya Dass

CS 6204 Paper Presentation

10/10/2006

Agenda

IntroductionContribution of the paperDMAP modelAnalytical ModelNumerical & Graphical ResultsApplicability and conclusion

IntroductionMIPv6 : Network level protocol which is extension of

Mobile IP designed to authenticate MN using IPv6 addresses

MN have permanent IP address on home networkMN roams into subnet acquire CoA (DHCP) from that

subnetBinding update(address mapping CoA with MN’s

permanent IP) sent to HA(Special router on home network)

CN -> HA(intercepted and tunneled) -> MNTriangular routing avoided by MN sending binding

update to CN(address obtained from source header)

MN’s discovery of new subnet : Router supporting neighbor discovery operational on each subnet. Send router discovery message periodically.

MIPv6 Goal : Enable mobility in IPv6 Maintain roaming connections in IP based

networks Reduce overall network signaling cost

Approaches to reduce network signaling cost MIP-Regional Registration (MIP-RR) Hierarchical MIPv6 (HMIPv6) Intra - Domain mobility management protocol

(IDMP)

MIP - RR

HA knows MN by Regional care of address (RCoA) ie. GFA’s routable address

Local movement: MN’s CoA(Foreign agent address) updated in Gateway Foreign Agent (GFA) , RCoA is same

Regional movement : MN’s RCoA (new GFA IP address) change informed to HA and CoA updated in GFA

Drawbacks- Not consider service management induced network cost

FA GFA

Visited Domain

MN

Home Network

HA

IP Network

FA

HMIPv6

AR announce MAP(hierarchy of routers) identity by means of router advertisement packets

Intra-regional Movement : CoA change propagated to MAP, RCoA is same

MAP Domain boundary movement : RCoA change propagated to HA and CN, CoA recorded in new MAP

Drawbacks-MAP statically configured and shared by all MN

IDMP

Domain Region(HMIPv6,MIP-RR)Mobility agent MAPFast Handoff - MA multicasts packets to neighboring

agents during Handoff transient Packets buffered at each SA(subnet agent) until MN

registerspaging support

MA initiates paging by multicasting solicitation within the current paging area

packets buffered at MA until MN updates exact location

Drawbacks

No mechanism to determine MAP domain size per MN to reduce network signaling cost

Contribution of the Paper

Determine best DMAP domain size per MN dynamically according to its mobility and service characteristics to reduce network and signaling cost

DMAPExtends HMIPv6Dynamic Mobility Anchor Points(Access routers

chosen) for each MNMN determines dynamically when and where to

launch DMAP for minimizing network costDMAP domain size depends on MN’s mobility and

service characteristicsHA and CN know MN by RCoALocation Handoff : MN moves across subnet

boundary within DMAP region

Location + Service Handoff : MN moves across DMAP boundary

Implement DMAP by DMAP table lookup design using binding request messages defined in MIPv6 and HMIPv6 RCoA - CoA routing function performed by

DMAP through simple table lookupScaleable - All AR’s DMAP enabledAssumption :

The AR of the first subnet that MN moves into after DMAP domain change is chosen DMAP

After service area is crossed, if MN selects AR of subnet just crossed as DMAP: MN determines size of new service area Obtains RCoA & CoA from current subnet

registers (RCoA,CoA) to current DMAP by binding request message

Inform HA and CN of new RCoA using standard Mipv6

Packet delivery route: CN->DMAP->MN (tunneling or direct)

MN’s service area - K, IP subnets

Goal : Dynamically determine optimal service area (K) per MN

Special case : K is constant for all MN’s ???

: K is 1 ???

- Degenerates to HMIPv6

- Degenerates to MIPv6

DMAP : Integrated Mobility and Service Management in MIPv6

Inter-Regional move(1 to 2):(Service+Location Handoff) AR of subnet B is new DMAP MN’s service area - K subnets calculated MN obtains RCoA and CoA from subnet B Entry (RCoA , CoA) recorded in routing table of AR

of subnet B HA and CN informed of RCoA address change

Intra-regional move(within 2) : (Location Handoff) MN acquires CoA from subnet DMAP still in subnet B DMAP informed of CoA address change

Large Service area : DMAP not change often Communication cost for service data delivery

high : CN->DMAP->MN Location update cost is low

Small Service area : DMAP changed often Communication cost for service data delivery

low Cost of informing HA and CN of DMAP change

is high

Tradeoff

• MN lookup in built table : and as a function of its location, time of the day and day of the week.

F(K) - Number of hops as a function of K(number of subnets) : Determined dynamically by MN

Assumption : Fluid flow model :

Average number of hops between 2 communicating models separated by K subnets is

Analytical Model

Find : Optimal service area using SPNWhy SPN

Deal with general time distribution of events Deal with large number of states Expressiveness to reason about MN’s

behavior

Stochastic Petri Net Model

Intra-regional move

MN obtains CoA

Register new CoA

with DMAP

Move makes MN cross service area

Token in the place “moves” in SPN : Subnet crossing event by MN

Mark(P) : Number of tokens in Place PMark(Xs) : Number of subnets crossed by MN

since it enters a new service area : One hop communication delay per packet in

the wired network : Ratio of communication delay in wireless to

wired networkF(Mark(Xs)+1) :Number of hops between

current subnet and DMAP( +1 for initial condition that Mark(Xs)=0)

Transition rate of MN2DMAP 1/Communication time of MN informing

DMAP of new CoA

Communication delay per packet in the wireless network

CoA address change propagated to DMAP in the wired network

Transition rate of NewDMAP

: Average hop distance between MN and HA : Average hop distance between MN and CN N : Number of CNs, MN concurrently engages

Communication time for MN to inform N CN’s and HA in the wired network

Semi-Markov state representation( a , b )

a : Mark(Moves) b : Mark(Xs) Pi : Steady state probability that Mark(Xs)

= i where 1 i K

C i,service : Network communication overhead to service a data packet when MN in i th subnet in service area

Communication delay in the wireless link from the AR to the MN

Delay between the DMAP and a CN in the fixed network

Delay from DMAP to the AR of the MN’s current subnet in the fixed network

C i,location : Network signaling overhead to service a location handoff when MN in i th subnet in service area

Clocation : Average communication cost to service a move operation by MN weighted by respective Pi probabilities

i < K : MN inform DMAP of CoA change

i = K : Location + Service to inform HA and N CNs of RCoA change

Total communication cost per time unit

: Data packet rate between MN and CNs : MN’s mobility rate

Numerical ResultsBasic MIPv6 - No DMAP

Communicationdelay in wireless link from AR to MN

Communication delay from CN to AR in wired network

Communication cost for servicing a packet delivery

Communication cost for servicing a location handoff

Delay in the wireless link from the MN to the AR of the subnet that it just enters into

Delay from AR of the subnet MN enters into, to the CNs

Delay from that AR to the HA

Total cost per time unit for servicing data delivery and mobility management operations

F(K) = , = = 30 , = 10 and normalized with =1

DMAP stays close to MN to avoid CN-DMAP-MN(service cost reduction)

DMAP area large (mobility cost reduction)

Degenerates to Basic MIPv6

DMAP degenerates to HMIPv6

DMAP degenerates to basic MIPv6

Kopt = Kh

* ,,CHMIPv6 -CDMAPfor low SMR (mobility management cost dominates data delivery cost)

* Threshold at which DMAP degenerates to HMIPv6

Conclusion:

DMAP incurs less network overhead than HMIPv6

Test Assumption

Average number of hops between DMAP and MN separated by k subnets is F(k) =

Cost difference curves are not sensitive to form of F(k)

Assumption of F(k) =

justified

Applicability and conclusion

Novel DMAP for integrated mobility and service management per MN

Procedure to find Kopt that minimizes overall communication cost

MN dynamically looks up Kopt

DMAP outperforms basic MIPv6 at low SMR & HMIPv6 at low and high SMR

Future : Test for sensitivity to other time distributions

Thank you