The Ad hoc On Demand Distance Vector (AODV) routing algorithm is a routing protocol designed for ad hoc mobile networks. AODV is capable of both unicast and multicast routing. It is an on demand algorithm, meaning that it builds routes between nodes only as desired by source nodes. It maintains these routes as long as they are needed by the sources. Additionally, AODV forms trees which connect multicast group members. The trees are composed of the group members and the nodes needed to connect the members. AODV uses sequence numbers to ensure the freshness of routes. It is loop-free, self-starting, and scales to large numbers of mobile nodes.
AODV builds routes using a route request / route reply query cycle. When a source node desires a route to a destination for which it does not already have a route, it broadcasts a route request (RREQ) packet across the network. Nodes receiving this packet update their information for the source node and set up backwards pointers to the source node in the route tables. In addition to the source node's IP address, current sequence number, and broadcast ID, the RREQ also contains the most recent sequence number for the destination of which the source node is aware. A node receiving the RREQ may send a route reply (RREP) if it is either the destination or if it has a route to the destination with corresponding sequence number greater than or equal to that contained in the RREQ. If this is the case, it unicasts a RREP back to the source. Otherwise, it rebroadcasts the RREQ. Nodes keep track of the RREQ's source IP address and broadcast ID. If they receive a RREQ which they have already processed, they discard the RREQ and do not forward it.
As the RREP propagates back to the source, nodes set up...
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...tree for the life of the multicast group. Because the network nodes are mobile, it is likely that many link breakages along a route will occur during the lifetime of that route. The papers listed below describe how link breakages are handled. The WMCSA paper describes AODV without multicast but includes detailed simulation results for networks up to 1000 nodes. The Mobicom paper describes AODV's multicast operation and details simulations which show its correct operation. The internet drafts include descriptions of both unicast and multicast route discovery, as well as mentioning how QoS and subnet aggregation can be used with AODV. Finally, the IEEE Personal Communications paper and the Infocom paper details an in-depth study of simulations comparing AODV with the Dynamic Source Routing (DSR) protocol, and examines each protocol's respective strengths and weaknesses
Stephen Kern, a professor of history at The Ohio State University, wrote the chapter “Wireless
Routing scheme means to find a path from once place to another on which packets can travel. In most of the cases, we need multiple routers in order to route the packet to the destination. Routing contains three elements:
The attacks targets the routing information which is being exchanged among nodes. The data in the table is altered and attacker then attracts or repel network traffic, generate false error messages, increase latency or even partition the network. The next node generally depends on the previous node(s) table to create routing paths.
With an IPv4 network, all the work consisting of network renumbering and assigning of new address schemes would had been done manually. Another useful feature of IPv6 is the multi-homing technique. It allows simultaneous connections which are established to two ISPs. Compared to IPv4, IPv6 has a much simpler packet header structure, which is designed to minimize the time and efforts that go in to header processing. IPv6 offers better end-to-end connectivity than its predecessor IPv4. The most exciting applications to emerge in todays world is peer-to-peer applications such as multi-player online games, video-conferencing (streaming), file sharing and
Also called tunneling attack, it is one of the most sophisticated attacks in MANETs. In this attack, a attacker captures data packets from one point in a network and tunnels them through an out of band channel to another attacker located several hops away, which relays them to its neighboring nodes. The tunnel between the attackers is actually faster than links between legitimate nodes, so the tunneled packets arrive sooner than packets through other routes. Therefore, the attackers are more likely to be included in the route and take an advantage for future attack. Detection of wormhole attack is generally difficult, and requires the use of an unalterable and independent physical metric, such as time delay or geographical location [25].
...ch an attacker resends valid frames that the attacker has intercepted in the middle of forwarding.
n.a. - n.a. - n.a. - n.a. - n.a. - A+E Networks. 2009. The 'Standard' of the 'Standard'. Web. The Web.
Each packet would begin at some specified source node and end at some other specified destination node. The particular route that the packet took would be unimportant, only the final results counted. Each packet would be tossed around like a hot potato from node to node, more or less in the direction of its destination, until it ended up in the proper place. If big chunks of the network were blown away, which wouldn't matter, the packets would still stay airborne, moving across the field by whatever nodes happened to survive.
Johnson, D., Maltz, D. (1996). Dynamic Source Routing in Ad-hoc Wireless network. Print ISBN: 0 79239697 0
8) Ian F. Akyildiz, Ismail H. Kasimoglu, “Ad Hoc Networks’’, Wireless sensor and actor networks: Research Challenges, Georgia Institute of Technology, USA, May-2004.
Open Shortest Path First (OSPF) is a link-state routing protocol which uses link state routing algorithm for Internet Protocol (IP) networks.Using OSPF, th convergence of a network can be done in very few seconds, loop-free paths can be guaranteed and better load-sharing on external links can be achievd. Every change in the topology of the network is identified within seconds using OSPF and it instantaneously computes the “shortest path tree” for every route using “Dijkstra's algorithm” . For that reason, OSPF requires a router which have a more powerful processor and more memory than any other routing protocols which leads to more elect...
The following flowchart shows the data relation and algotithm for estimate the position of user. The first step for GPS positioning is using the position of satellite and pseudorange from GPS receiver data to estimate the position of user. The simulation results for GPS satellite position are shown in T...
Clark, Martin P.. Data Networks, IP, and the Internet: Protocols, design, and operation. Chichester, West Sussex, England: J. Wiley, 2003.
Computer systems route planning is well developed. Originally they were created for simple virtual environments and the program, which simulates the action of the
The primary goal in routing multicast connections is to make efficient use of the network resources and to establish fast connections for data transmission. The network is often defined by a graph G(V,E) . Multicast routing protocols are been used in practical systems such as multicast backbone(M bone).M bone chooses the shortest path to each destination using the IP routing mechanism.Multicast routing in ATM Switch performs two basic functions such as switch and queuing.