Ing-Ray Chen, Weiping He, and Baoshan Gu Paper Presented by: Vidhya Dass

1. CS 6204 Paper Presentation 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 10/10/2006

2. Agenda • Introduction • Contribution of the paper • DMAP model • Analytical Model • Numerical & Graphical Results • Applicability and conclusion

3. Introduction • MIPv6 : Network level protocol which is extension of Mobile IP designed to authenticate MN using IPv6 addresses • MN have permanent IP address on home network • MN roams into subnet acquire CoA (DHCP) from that subnet • Binding update(address mapping CoA with MN’s permanent IP) sent to HA(Special router on home network) • CN -> HA(intercepted and tunneled) -> MN • Triangular routing avoided by MN sending binding update to CN(address obtained from source header)

5. 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)

6. 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

7. Visited Domain Home Network GFA FA HA FA MN IP Network

8. 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

10. IDMP • Domain Region(HMIPv6,MIP-RR) • Mobility agent MAP • Fast Handoff - MA multicasts packets to neighboring agents during Handoff transient • Packets buffered at each SA(subnet agent) until MN registers • paging support • MA initiates paging by multicasting solicitation within the current paging area • packets buffered at MA until MN updates exact location

11. 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

12. DMAP • Extends HMIPv6 • Dynamic Mobility Anchor Points(Access routers chosen) for each MN • MN determines dynamically when and where to launch DMAP for minimizing network cost • DMAP domain size depends on MN’s mobility and service characteristics • HA and CN know MN by RCoA • Location Handoff : MN moves across subnet boundary within DMAP region

13. 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 lookup • Scaleable - All AR’s DMAP enabled • Assumption : • The AR of the first subnet that MN moves into after DMAP domain change is chosen DMAP

14. 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)

15. 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

16. DMAP : Integrated Mobility and Service Management in MIPv6

17. 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

18. Tradeoff • 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

20. 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

21. Analytical Model • Find : Optimal service area using SPN • Why SPN • Deal with general time distribution of events • Deal with large number of states • Expressiveness to reason about MN’s behavior

22. Stochastic Petri Net Model Register new CoA with DMAP Intra-regional move MN obtains CoA Move makes MN cross service area

24. Token in the place “moves” in SPN : Subnet crossing event by MN • Mark(P) : Number of tokens in Place P • Mark(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 network • F(Mark(Xs)+1) :Number of hops between current subnet and DMAP( +1 for initial condition that Mark(Xs)=0)

25. 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

26. 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

27. Semi-Markov state representation( a , b ) • a : Mark(Moves) • b : Mark(Xs) • Pi : Steady state probability that Mark(Xs) = i • where 1 i  K

28. C i,service : Network communication overhead to service a data packet when MN in i th subnet in service area Delay from DMAP to the AR of the MN’s current subnet in the fixed network Delay between the DMAP and a CN in the fixed network Communication delay in the wireless link from the AR to the MN

29. 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 : Location + Service to inform HA and N CNs of RCoA change i < K : MN inform DMAP of CoA change

30. Total communication cost per time unit •  : Data packet rate between MN and CNs •  : MN’s mobility rate

31. Numerical Results • Basic MIPv6 - No DMAP Communication cost for servicing a packet delivery Communicationdelay in wireless link from AR to MN Communication delay from CN to AR in wired network Communication cost for servicing a location handoff Delay from AR of the subnet MN enters into, to the CNs Delay in the wireless link from the MN to the AR of the subnet that it just enters into Delay from that AR to the HA

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

33. DMAP area large (mobility cost reduction) DMAP degenerates to HMIPv6 DMAP stays close to MN to avoid CN-DMAP-MN(service cost reduction) F(K) = ,  =  = 30 ,  = 10 and normalized with =1 Degenerates to Basic MIPv6

34. Kopt = Kh DMAP degenerates to basic MIPv6

35. * ,,CHMIPv6 -CDMAPfor low SMR (mobility management cost dominates data delivery cost) * Threshold at which DMAP degenerates to HMIPv6 Conclusion: DMAP incurs less network overhead than HMIPv6

36. Test Assumption • Average number of hops between DMAP and MN separated by k subnets is F(k) =

37. Cost difference curves are not sensitive to form of F(k) Assumption of F(k) = justified

38. 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

39. Thank you