TARUN VARSHNEYvarshney@live.inDepartment of Information TechnologyABES Engineering CollegeMANET : The Art of Networkingwithout a Network
Wireless Networks• Computer network that is wireless• Infrastructure-based networks• Less expensive to setupIP backboneServerRouterGateways
Disadvantages• Disaster areas• no infrastructure• Large construction sites• Too expensive• Inconvenient• Military operations
Solution???• Mobile ad hoc network• Mobile ad hoc network (MANET), or simply ad hoc network, comprisesnodes that freely and dynamically self-organize into arbitrary and temporarynetwork topology without any infrastructure support.
MobileRandom and perhaps changingAd HocNot engineered i.e. made or happening only for a particular purpose orneed, not planned before it happensNetworkNetwork, is a collection of systems and other hardware interconnected bycommunication channels that allow sharing of resources and informationMANET: Mobile Ad hoc Network
MANET is a self-configuring network of mobile nodes connected bywireless links - the union of which form an arbitrary topology. Individual nodes act as routers Minimal configuration and quick deployment make ad hoc networkssuitable for emergency situations like natural or human-induceddisasters, military conflicts, emergency medical situations etc. Such a network may operate in a standalone fashion, or may beconnected to the larger Internet.MANET: Mobile Ad hoc Network (continued)
Mobile Ad Hoc Network (MANET) is a collection of two or moredevices or nodes or terminals with wireless communication andnetworking capability that communicate with each other without theaid of any centralized administrator also the wireless nodes that candynamically form a network to exchange information without using anyexisting fixed network infrastructureMANET: Mobile Ad hoc Network (continued)
MANETs: OperationABCDEFInternetEGatewayStand-alone MANETAfter one of the nodes is configured as a gateway, the entire network isconnected to an external network like Internet
Collision – Hidden-Station Problem• A wishes to communicate with B. However A cannot detect communication from C butcan detect communication from B.• C also wishes to communicate with B. Again C cannot detect communication from A butcan detect Communication from B.• C is hidden from A and A is hidden from C.• Both A and C transmit and their signals collide leading to loss of both packets.
Collision – Exposed-station Problem• Nodes A, B, and C can all detect communications from one another. However, Only C candetect communication from D.• Node B wishes to send to Node A and Node C wishes to send to Node D.• So Node B begins transmitting to Node A and Node C recognizes this. The medium is inuse so Node C can not transmit to Node D.• Even though both transmission requests could be made going in opposite directions, thetransmission does not happen. This is because Node C is exposed to Nodes A and B while Dis not.
Routing is the process of selecting paths in a network along which to sendnetwork trafficRouting Protocols are the set of rules and regulation that are must followedduring the communication over the network.MANET: Routing and Routing Protocols
MANET: Classification of Routing Protocol Proactive Routing Protocol or Table Driven Approaches:Maintain regular and up to date routing information about each node in the network bypropagating route updation at fixed time interval throughout the network. Reactive Routing Protocol:Establish the route to a destination only when there is a demand for it.Also called as “Demand Protocol”. Hybrid Routing Protocol:Combination of proactive and reactive protocolThe route is established with the proactive routes and uses reactive flooding for newmobile nodes.
Reactive Routing ProtocolAd Hoc On-Demand Distance Vector (AODV)Dynamic Source Routing (DSR)Associativity Based Routing (ABR) Proactive Routing ProtocolDestination-Sequenced Distance-Vector Routing (DSDV)Optimized Link State Routing (OLSR)The Wireless Routing Protocol (WRP)MANET: Routing Protocols (continued) Hybrid Routing ProtocolTemporary Ordered routing Algorithm (TORA)Zone Routing Protocol (ZPR)Order One routing Protocol(OOPR)
Constructs route on demand and reduce routing load. Uses table driven routing framework. Destination sequence number for routing packets to destination mobile nodes. Location independent algorithm. Bi-directional route. Packet send from source to destination, floods the network with the RREQpackets. All mobile node receive RREQ from neighbor or update message thenchecks routing table to find out that if it is the destination node or if it has freshroute to the destination then unicast RREP which is routed back on a temporaryreverse route generated by RREQ from source node or else it re-broadcast RREQ.Ad Hoc On-Demand Distance Vector (AODV)
The Internet Engineering task Force MANET working group suggests twodifferent types of matrices for Evaluting the performance of the protocols of theMANETs Qualitative Metrics Quantitative MetricsPerformance and Evaluation issues of Routing Protocols
Qualitative MetricsQualitative metrics include the :• Loop Freedom• On-Demand Routing Behavior• Proactive Behavior• Security• Unidirectional Link Support• Sleep Mode
Quantitative MetricsQuantitative metrics broadly includes the:• End-to-end data throughput and delay• Route Acquisition Time• Out-of-Order Delivery• Efficiency
Challenges in Securing MANETsTo secure an ad hoc network, the following attributes may be considered:- Availability- Confidentiality- Integrity- Authentication
Challenges in Securing MANETs• Security exposures of ad hoc routing protocols are due to two different types of attacks:- Active attacks through which the misbehaving node has to bear some energy costs inorder to perform some harmful operation, and- Passive attacks that mainly consist of lack of cooperation with the purpose of energysaving.• Nodes that perform active attacks with the aim of damaging other nodes by causingnetwork outage are considered to be malicious.• Nodes that perform passive attacks with the aim of saving battery life for their owncommunications are considered to be selfish• Selfish nodes can severely degrade network performances and eventually partition thenetwork
Challenges in Securing MANETs• In a wormhole attack a malicious node can record packets (or bits) at onelocation in the network and tunnel them to another location through aprivate network shared with a colluding malicious node.• Most existing ad hoc routing protocols would be unable to find consistentroutes to any destination• When an attacker forwards only routing control messages and not datapackets, communication may be severely damaged
Challenges in Securing MANETs- Wormhole AttacksInitialRoutingbefore attack
Challenges in Securing MANETs- Wormhole AttacksInitialRoutingbefore attack
Challenges in Securing MANETs- Wormhole AttacksTunnel packets received in oneplace of the network andreplay them in another placeThe attacker can have no keymaterial. All it requires istwo transceivers and onehigh quality out-of-bandchannel
Challenges in Securing MANETs- Wormhole AttacksMost packets will berouted to thewormholeThe wormhole candrop packets ormoresubtly, selectivelyforward packetsto avoid detection
MANET Applications• Tactical Networks• Military communication, operation• Automated Battlefields• Sensor Networks• Home applications: allow users to manage home device locally andremotely
MANET Applications (continued)• Emergency Services• Replacement of a fixed infrastructure in case ofearthquake, hurricanes• Home and Enterprise Networking• Shared whiteboard applications• Use PDA to print anywhere• Entertainment• Multi-user games• Robotic pets
• MANETs is challenging and promising system concepts• Requires new type of architectures and protocols• Open areas• Secure routing protocol• Quality of service• Low power consumptionConclusion
Conclusion• Security of ad hoc networks has recently gained momentum in theresearch community• Due to the open nature of ad hoc networks and their inherent lack ofinfrastructure, security exposures can be an impediment to basicnetwork operation• Security solutions for MANET have to cope with a challengingenvironment including scarce energy and computational resources andlack of persistent structure
• The solutions presented in this presentation only cover a subset of allthreats and are far from providing a comprehensive answer to the securityproblem in ad hoc networks• They often address isolated issues away from a global approach to security• As the technology for ad hoc wireless networks gains maturity,comprehensive security solutions based on realistic trust models andaddressing all prevalent issues like routing, key management andcooperation enforcement are expected to appearConclusion