Département Réseau, Sécurité et Multimédia Rapport d'Activités 2008

ecause it offers a generic framework overIPv6 that can be easily deployed.In 2007, we focus on mobility impacts on theSHIM6 operations. SHIM6 is a protocoldesigned to support multihoming. However,we envision that most nodes in the Internetwill be mobile, therefore we analyze the SHIM6operation in mobile environment.On one hand, we may consider to associateSHIM6 with a mobility protocol, such as MobileIP. However, such a combination mightintroduce an important overhead in terms ofconception and implementation (two abstractlayers in the IP layer) and in terms ofoverhead since a packet may be encapsulatedseveral times. Therefore, we propose in [2] thestudy of SHIM6 operation on a mobile node.We conclude that with a proper use of UpdateRequest and Update Acknowledgementmessages, a SHIM6 context can be updatedwith new IPv6 addresses that are acquiredwhile the node is on the move. The mainconcern of such a usage is the handoverlatency. The new network discovery seems tobe the major part of the handover process,and we find out that IPv6 optimizations forrouter and prefix discovery that were designedto enhanced mobility protocols can be usedwith SHIM6 as well.References[1] Geoff Huston, Multi-Homing and Identity inIPv6, Internet Society Publications, June 2004[2] Amine Dhraief, Nicolas Montavont, TowardMobility and Multihoming Unification: theSHIM6 protocol : a case study, IEEE WirelessCommunications and Networking Conference(WCNC 2008), March 31 - Avril 3 2008, LasVegas, USAThe experimentations we performed gave usnew perspective and highlighted someadditional issues. In a multihomedenvironment, when a mobile node acquires anew address, we need a decision algorithmthat indicates whether the new address mustbe used or not. We are currently investigatingthis decision algorithm.ConclusionWith the large amout of network protocols thathave recently been proposed, it is important toevaluate the features and the overheadintroduced by each of them. While we envisionthat in a near future most nodes will be mobileand multihomed, we need to support bothmechanisms. Instead of putting togetherseveral protocols, we showed that SHIM6 maybe used for both mobility and multihomingsupport. Now, we still need to determine theoverhead of this protocol compared to others,and we also need to adjust some parametersof the SHIM6 protocol, such as the decisionalgorithm or the movement detectionmechanism.28 Extract of Pracom’s Annual Report 2008