The 1 st International Conference on Next Generation Network (NGNCON 2006)Hyatt Regency Jeju, Korea / July 9 - 13, 2006 MoC3-8

Scalability Analysis ofMANET DAD Protocols

Sang-Chul Kim', Jong-Moon Chung2

('Kookmin University, School of Computer Science, 136-702, 86 1-1 Chongnung-dong, Songbuk-gu, Seoul,

Korea, Tel: +82-2-910-5462, Fax: +82-2-910-4868, Email: sckim7gkookmin.ac.kr)(2Yonsei University, School of Electrical and Electronic Engineering, 120-749, 134 Shinchon-dong,

Seodaemun-gu, Seoul, Korea, Tel: +82-2-2123-5863, Fax: +82-2-313-2879, Email: jmcgyonsei.ac.kr)

Abstract

This paper proposes a novel method to perform a

quantitative analysis of message complexity and

applies this method in comparing the message

complexity among the mobile ad hoc network

(MANET) address autoconfiguration protocols.

1 Introduction

Mobile ad hoc networks (MANETs) are

self-organizing wireless networks where mobile nodeshave routing capabilities to be able to forward packetsto communicate with one another over multi-hopwireless links without any fixed communicationinfrastructure, such as a base station or an access point.Therefore, it is essential for all nodes to be able to

perform the operations required for configuration of

unique addresses to execute proper routing of datapackets in a M\ANET. Address autoconfiguration isan important issue in MANETs since addresspre-configuration is not always possible. MANETscurrently depend on the mechanism of checking IP

addresses of nodes to decide whether the connectionand identification of nodes participating in a MANETare established or not [1]. Based on the conventionalmethod stated in [2], DAD can be classified as StrongDAD and Weak DAD. Strong DAD uses an address

discovery mechanism where a node randomly selectsan address and requests the address within a M\ANETby checking if the address is being used in the

M\ANET. Based on a reply for the claimed request,

which needs to arrive at the node within a finitebounded time interval, the node can detect an address

duplication in the MANET [1]. Weak DAD is

proposed by [2], where ad hoc routing protocols are

89-955301-4-6 98560 @2006 OSIA

used to detect address duplication by modification ofthe routing protocol packet format. MANET routingprotocols can be classified into proactive andon-demand. Proactive routing protocols using periodicneighbor discovery messages and topology updatemessages give route information to each node before a

node sends data packets to a destination. As a statefulprotocol, M\ANETconf [3] uses a mutual exclusionalgorithm for a node to acquire a new IP address.Therefore, if a requester wants to acquire an IP

address, the IP address should be approved by allnodes in a M\ANET. In other related research, Wenigerand Zitterbart summarized the current approach andfuture directions of address autoconfiguration in

MANETs [4]. Jeong et al. studied hybrid ad hoc IP

address autoconfigurations in [5]. In [6] Zhou andMutka investigated prophet address allocation forlarge scale MIANETs. Additionally, Weniger proposeda passive autoconfiguration for MANETs in [7]. Sincethe autoconfiguration protocols in the above sectionhave been composed of key steps introduced in StrongDAD, Weak DAD and MANETconf based on authors'literature review, this paper focuses on formalizinghow to analyze and compare the message complexityof the key steps used in Strong DAD, Weak DAD andMANETconf.

2 ExperimentA MANET is represented as an undirected graph

G(V, E) where V is a finite nonempty set of nodes,

which can be represented as V= { VIf, V20,, VG }

where Il =W and E is a collection of pairs of distinctnodes from V that form a link, which can be

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conflict probabilities.represented as E= {El , E2 I .. Ew . In order to

analyze the message complexity of each addressautoconfiguration protocol, a standalone M\ANETenvironment is needed, where the MANET nodeshave no connection to an external network like the

Internet. Therefore, a computer simulator was

developed where nodes are randomly distributed withuniform density in a network area of 1km2. A

discrete-event simulator was developed in Matlab in

order to verify the various network topologies and to

calculate the message complexity of each addressautoconfiguration protocol. The random nodegenerator and simulator performance was verified (forthe numbers of nodes 100, 125, 150, and 175) so thatthe average number of nodes per cluster as well as

several specs in the ADB algorithm [8] matched withthe results in [8], which was performed by QualNet,with less than a 1% difference for almost all cases. In

the Strong DAD protocol, five is used for retry count

limit (n) and three is used for DAD retry count limit

(m). In the Weak DAD and MANETconf protocols,five is used for retry count limit (n) and one is used forDAD retry count limit (m). In addition, 1OOm isselected as the transmission range of nodes. Thenumber of nodes is varied from 10 to 50 for thetransmission range.

3 Message Complexity AnalysisFig. 1 shows the message complexity of the singlenode joining case for the Strong DAD protocol basedon the different conflict probabilities. In Figs. 1-4, thehorizontal axis represents the number of nodes in thenetwork area and the vertical axis indicates thenumber of messages for each case. As the conflict

probability increases, it is shown that the number of

messages to resolve the duplicated IP address alsoincreases. Figs. 2 and 3 show the message complexityof Weak DAD respectively for proactive routingprotocols and on demand routing protocols, based on

the different conflict probabilities. Fig. 4 shows the

message complexity of the single node joining case ofthe M\ANETconf protocol based on the different

R=lOOm (Single Node Joining Case: Strong DAD)

Fig. 1. Message complexity of Strong DAD.

R=lOOm wVeak DAD with Proactive Routing Protocols)

Fig. 2. Message complexity of Weak DAD withproactive routing protocols.

u2

R=lOOm (Weak DAD with On Demand Routing Protocols)

25 30No of Nodes

Fig. 3. Message complexity of Weak DAD with on

demand routing protocols.

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10

R=lOnm (Single Node Joining Case: MANETcon)

Fig. 4. Message complexity of MANETconf.

Figs. 1-4 show that as the conflict probability

approached 1 the message complexity approaches the

derived theoretical message complexity upper bounds.

However for the case of NIANETconf in Fig 4, due to

the difference in the consideration of the stateful

addressing procedures, a small difference between the

upper bound and the p=1 case can be observed.

4 Conclusion

For the conflict probability of 0.5, 0.7, 0.9 and 1,Weak DAD with proactive routing protocols has thesmallest message complexity and Strong DAD has thelargest message complexity. However, since proactiverouting protocols depend on a periodic message to

update the network topology and on demand routingprotocols do not need a periodic message, it is not fairfor the two routing protocols to be compared using thenumber of messages. The result above can be used

only in the case where the Weak DAD protocol uses

M\ANET routing protocols for nodes to configure its

IP address and solve the duplicate IP address detection.Based on the simulation results and analysis of themessage complexity, when nominal n, m values andtransmission range have been assigned in a singlenode joining case with p < 1, the message complexitycan be compared as follows: Weak DAD withproactive routing protocol < Weak DAD with on

demand routing protocol < MANETconf < StrongDAD. In the view point of the message complexity,

when a MANET area is composed of a high conflict

probability, Weak DAD with MANET routing

protocols becomes a more suitable protocol than

MANETconf and Strong DAD since Weak DAD with

M\ANET routing protocols provides both routing and

address autoconfiguration and much less message

complexity compared to MANETconf and Strong

DAD.

5 References

[1]C. E. Perkins, J. T. Malinen, R. Wakikawa, E. M. Royer,

and Y. Sun, "IP address autoconfiguration for ad hoc

networks," IETF draft, 2001,

http //www.cs.ucsb.edu/-ebelding/txt/autoconlf.txt.[2]N. H. Vaidya, "Weak duplicate address detection in

mobile ad hoc networks," Proc. ACM MobiHoc 2002, pp.

206-216, June 2002, Lausanne, Switzerland.

[3] S. Nesargi and R. Prakash, "MANETconf:

Configuration of hosts in a mobile ad hoc network,"

Proc. IEEE Infocom 2002, June 2002, New York,

USA.

[4]K. Weniger, and M. Zitterbart, "Address

autoconfiguration in mobile ad hoc networks: Current

Approaches and Future Directions," IEEE Network, pp.

6-1 1, Jul./Aug. 2004.

[5]J-. P. Jeong, J. Park, H. Kim, and D. Kim, "Ad hoc IP

address autoconfiguration," IETF draft, July 2004.

[6] H. Zhou, L. M. Ni, and M. W. Mutka, "Prophet

Address Allocation for Large Scale MANETs," Ad

Hoc Networks Journal, vol. 1, issue 4, pp. 423-434,

Nov. 2003.

[7]K. Weniger, "Passive duplicate address detection in

mobile ad hoc networks," Proc. IEEE WCNC 2003, Mar.

2003, New Orleans, USA.

[8] C-. C. Shen, and C. Srisathapornphat, and R. L. Z.

Huang, and C. Jaikaeo, and E. L. Lloyd, "CLTC: A

cluster-based topology control framework for ad hoc

networks," IEEE Trans. Mobile Computing, vol. 3,

no.1, pp. 18-32, Jan.-Mar. 2004.

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