User Oriented Regional Registration-Based Mobile Multicast Service Management in Mobile IP Networks Ing-Ray Chen and Din

1. User Oriented Regional Registration-Based Mobile Multicast ServiceManagement in Mobile IP NetworksIng-Ray Chen and Ding-Chau Wang Presented By A. B. C.

2. Multicasting According to Wikipedia: “IP multicast is a technique for one-to-many communication over an IP infrastructure in a network. It scales to a larger receiver population by not requiring prior knowledge of who or how many receivers there are. Multicast uses network infrastructure efficiently by requiring the source to send a packet only once, even if it needs to be delivered to a large number of receivers.” • Multicasting is not BROADCASTING though • Group management is a key attribute of multicasting

3. Uses of Multicasting • Video/Voice conferencing • Database replication • IP television • Bulk Software updates to subscribers over the network/intranet

4. How is Multicasting achieved? • IGMP – Internet Group Management Protocol • Multicast distribution trees • Use of class D addresses 224.0.0.0 – 239.255.255.255 • Essentially Multicasting boils down to sending and receiving from a common address.

5. Multicasting challenges within Mobile IP Dynamic Topology • No fixed underlying infrastructure makes the creation of Multicast distribution tree difficult. • The router will keep on asking the question:“How do I send this message to the group member that is not within my transmission range???” Dynamic Group Membership • Changing infrastructure compromises the “common” destination that the publisher and subscribers rely upon for data dissemination

6. So what we need is URRMoM…a.k.a “Your Mom” • It actually stands for user-oriented regional registration based mobile multicast protocol • Supratik will explain why “Your MoM” does things way better than some other “MoM”s • Fenye will explain SPNP performance model to quantify the claims in the paper made about “Your MoM” • Reghu will present the analytical and simulation results followed by the conclusions • Let the best “MoM” win!!!!

7. Some background on “MoM” Two basic schemes were originally proposed by the IETF… Remote Subscription • Mobile Host always needs to subscribe to its multicast group when it enters or changes a foreign networks. • This essentially means that the current local router of the Mobile host is made part of the Group subscription tree • Pros – Optimal trees are constructed for message delivery • Cons – Too many reconstructions of the delivery tree. Bi-directional tunneling • Multicast delivery tree stays the same since the Home Agent of the mobile host is responsible for sending the message out to the Mobile Host… • Pros – The Multicast Delivery tree stays the same even though source and destination nodes hop across networks • Cons – Routing path is not optimal and Foreign agents may receive duplicate packets

8. “Your MoM”?? Is going to combine the advantages of Remote Subscription with Bi-directional tunneling, without the disadvantages…

9. Lets look at some proposed ways... • Local registration to support Multicast services • Usage of Multicast Agents(MA) • mMom - A hybrid approach of Bi-directional tunneling and Remote Subscription - If Mobile Host is highly mobile BT is used otherwise RS is used - The FA makes the determination whther MH is mobile or immobile Cons – Does not factor in co-located care of address in MIP(???) • RBMoM - Uses MMA to tunnel packets to the FA serving the MH - Current MMA information is stored in the MH’s HA - If MH is out of MMA range, MMA handoff occurs - Agent Table updates at FA to know which MMAs are around - MH can look at Agent table to figure out the nearest MMA. Cons – Excessive Communication Overhead

10. URRMOM Design Goals of URRMoM: • No overhead of maintaining Agent tables • Minimize network traffic generated due to Multicast packet delivery and Multicast tree maintenance • Simplicity, Scalability and Efficiency

11. Key Players of URRMoM • Mobile Multicast Agents (MMA) • Tunneling Multicast Packets to foreign agents • Maintain knowledge about the regional service area (number of subnets covered) • Unsubscribe from the Multicast tree • Mobile Host (MH) • Maintains a counter to record the number of subnets crossed within the service area of an MMA • Checks if the Foreign Agent of the subnet is part of the Multicast group • Checks if a counter has reached the regional area size • Subscribes to a new MMA • Foreign Agent (FA) • Receives tunneled messages from an MMA • Forward the tunneled messages to the Mobile host • Act as an MMA for Mobile Hosts

12. URRMoM Algorithm • MH moves across subnets • For every move the MH counter increases by one • If the MH encounters a FA within a subnet which is an MMA for other Mobile Hosts, the MH will change its regional MMA and set the counter to zero • If the MH moves across the regional service area, the new FA becomes the MH’s new MMA. The FA will subscribe to the Multicast tree in case its not an MMA originally. • When the MMA is no longer serving any MHs, it will unsubscribe itself from the multicast tree

13. Fig. 1 a Counter reset due to new FA being a MMA. b Counter reset due to service area handoff

14. Regional Service Area • The Mobile Host can make the determination of an optimal service area that will minimize the network traffic overhead. This optimal service area (R) will be compared against the current value of the MH counter to make MMA handoff decisions • The Mobile Host can guage the optimal service area based on the following parameters: • Mobility of Mobile Hosts • Number of Mobile Hosts • Size of the network • Topology of the network

15. Performance Model • A multicast group with a single source; • The source is a fixed host; • The multicast group membership does not change dynamically but mobile members may roam dynamically. M group members n by n mesh network

16. Performance Model • MH’s residence time in a FA is exponentially distributed with parameters μ. (mobility rate is μ) • MH’s expected residence time in one FA is 1/μ. MH’s expected residence time in n2-1 FAs is n2-1/μ. Thus, MH’s inter-arrival time to any FA is n2-1/μ. • The arrival rate of a single MH to any FA is λ:

17. Performance Model • Arrival-departure process of M members with respect to a FA: • Probability that a MMA does not contain any group member: • The average number of members being resided under one FA:

18. Performance Model • Every FA is capable of acting as a MMA. • Every MH keeps a counter to record number of FAs it has crossed from its current MMA. • A MH sets current FA as its new MMA when: • (1) current FA is a MMA; • (2) counter value equals to threshold R. (R is per-MH based depending on it service and mobility characteristics.) • Each MMA on average covers R subnets, group members. Thus, there are roughly MMAs in the system. • The probability that a FA (a MH just enters) is a MMA, denoted by PMMA:

19. Performance Model • Performance model for describing a MH’s behavior

20. Performance Model • We aim to find per-MH based optimal service area R, such that network traffic cost per time unit is minimized. • The optimal R is per-MH based, depending on MH’s service-to-mobility ratio. Multicast group management (tree maintenance) cost, will decrease as Rincreases Tunneling (multicast packet delivery) cost, will increase as Rincreases

21. Performance Model • Multicast tree maintenance per time unit: Per-hop communication cost Average number of hops between MMA and source Tree subscription / un-subscription rate Tree un-subscription rate Tree subscription rate

22. Performance Model • Multicast packet delivery per time unit: Per-hop communication cost Multicast packets delivery rate Hops from source to MMAs Hops from MMAs to MHs

23. Cost vs. R (varying n) • M=100, τ=0.025s, λp=10, β=15, μ = 0.00167 • Optimal service area size minimized

24. Cost vs. R (varying MHs) • 8x8 Mesh network • As M increases, optimal R decreases – multicast packet delivery cost dominates multicast tree maintenance cost

25. Effect of distance b/w source and MMA • When β increases, the optimal range R increases • Higher the disatnce, higher the maintenance cost – system prefers to have a larger service area to reduce rate of tree subscription/un-subscription operations • M = 100

26. Comparison – Maintenance Cost URRMoM always produces the least amount of network traffic compared with RS and RBMoM.

27. Comparison – Control Message Overhead

28. Comparison – Transmission Delay • URRMoM performs comparably with RBMoM since both use the optimizing R values • Basic RS scheme performs the best in terms of packet delay - at the expense of the much higher maintenance cost and control message overhead

29. SMPL Simulation – Cost vs. R for varying m

30. SMPL Simulation – Cost vs. R for varying n

31. Conclusions • Combines distinct performance advantages of remote subscription and bi-directional tunneling. • URRMoM has simpler system requirements and less computation complexity than RBMoM.