There are many characteristics and challenges that should be taken into consideration when developing multicast routing protocols, like the dynamically changing network topology, limitation of network scalability. There are different types of protocols like unicast protocols [1], [2], cluster based protocols [3] In this paper we discuss about multicast routing for vehicular Ad hoc network which is different from other Ad Hoc networks [4]. Generally there are two types of multicast routing protocols in wireless networks. Tree-based multicast routing protocol, mesh based routing protocol [5]-[8]. In the tree-based multicasting, structure can be very much unstable in multicast ad-hoc routing protocols, as it needs frequent re-configuration in dynamic network. One such example is Multicast extension for Ad-Hoc On-Demand Distance Vector (MAODV) and Adaptive Demand- Driven Multicast Routing protocol (ADMR). The second type is mesh-based multicast protocol. Mesh-based multicast routing protocols are more than one path may exist between a source destination pair, Core-Assisted Mesh Protocol (CAMP) and On-Demand Multicast Routing Protocol (ODMRP) are an example for these type of classification[9]. One approach to multicast is to maintain a multicast tree in straight roads. Existing protocols for multicasting encounters quite a lot of troubles in mesh maintenance and regular reconfiguration when link breakage occurs. The extreme dependency of these protocols on upstream and downstream nodes leads to storage and control overhead. Furthermore, various protocols consider the shortest path as a decisive factor for path selection, Existing forwarding state for the multicast distribution mesh for the source and the group. The nonexistence of data...
... middle of paper ...
...eed, then the node rediscovers the mesh and stable route. A forwarding node is always present in the network therefore the packet delivery ratio of proposed is high.
IV CONCLUSION
This paper proposed link stability based hop by hop multicast routing scheme that finds stable multicast path from source to receivers. The main goals of LSHBH are to maintain stable tree structure, by reducing receiver departures, and to construct low-cost trees, to reduce administrative costs and to lower error rate. Simulation is done over a large number of VANET nodes with wide range of mobility and the performance is evaluated. Finally, the simulations results confirm effectiveness of our proposed protocol in efficient multicast delivery in terms of packet delivery ratio, less control overheads. However in the future, we will seek better multicast routing with new smart scheme.
The attacker forwards only specific packets to next node, it generally chooses which kind of packet to forward. These attacks are effective if the attacker is in the path of the data flow. The attacker may choose to act as a black hole and just absorb the packet but then some nodes may declare it as failed. The assumption in multihop network is the trust relation among participating nodes about forwarding packets. Selective forwarding can also be caused by jamming or collision (physical or link layer) of a node outside the data flow.
Perhaps the most redundant, fault-tolerant of all network topologies is the mesh LAN. Each node is connected to every other node for a true point-to-point connection between every device on the network.
This constraint ensures that the hop-count for each node-pair (s, d) does not exceed the pre-specified bound〖 H〗_(s,d).
... of adjacent nodes (stations) is connected both ways. Does the application still work correctly? Now include more stations/lines and test again.
Johnson, D., Maltz, D. (1996). Dynamic Source Routing in Ad-hoc Wireless network. Print ISBN: 0 79239697 0
IPv6 has no fixed compatibility with IPv4. Therefore, from the beginning of the introducing IPv6, several transition techniques have been provided, The IPv6 transition mechanisms are a set of rules applied in hosts and routers, with some effective strategies for addressing and deployment, which are designed to transmit from IPv4 to IPv6 or vice versa with the least interferences. But some of these techniques had not been accepted by internet technical community due to the lack of adequate technical reliabilities. The most successful and widely used transition methods probably are Dual stack, Tunneling and Translation techniques. In the Dual stack technique, both IPv4 and IPv6 can perform concurrently on the same foundation. However, they both can use the same router but not all of the IPV4 policies are supported by IPv6 and in these cases other techniques can be used (Jayasekara et al, 2012). One of these techniques is tunneling, in this method IPv6 packets will be encapsulated in IPv4 packets to transfer across an IPv4 infrastructure. Furthermore, it can be said that several different tunneling technologies have been developed to enable IPv6 connectivity across an IPv4 network and vice versa, generally they have been classified as configured or automatic (Rooney, 2011)In automatic tunnels no pre-configuration is needed and the destination address will be calculated automatically from the IPv6 next-hop address of the IPv6 route, while in configured techniques the end-point hosts will require to configure their IPv4 addresses before the communications through some other techniques such as DHCP, manual configuration...etc. (Loshin, 1999). Another popular technique is translation, in this approach a special method will be provided to...
An Open Shortest Path First (OSPF) protocol enhancement to save energy using Energy Aware Routing (EAR) strategy
Spanning tree protocol is a protocol that prevents loops that are not wanted in a network. In order for a network to work properly it has to have only one active path between two network stations. If there are multiple active paths between stations loops can and will occur. When loops occur, there can sometimes be duplicate messages in the network. The loops are created by the network and if the devices that connect the network segments are all configured to forward, they will continuously forward frames into an endless network loop. If there are enough loops going then a frame will not reach its destination. The reason duplicate messages occur is because sometimes switches will see situations appear on both sides of it. When this occurs that is when spanning tree protocol comes in. In order to shut down the loops bridges and switches exchange BPDU messages with other bridges and switches to detect loops and then remove them by shutting down selected bridge interfaces. BPDU is short for bridge protocol data unit. Bridge protocol data units are part of the spanning tree protocol and they help describe and identify the parts of a switch port. The bridge protocol data unit allows switches to obtain information about each other. All the switches gather information from each other by exchanging data messages. In order for them to exchange messages they have to elect a root switch for the topology. The root switch has to be unique. The way they elect they have to have a unique switch for every local area network segment. To exchange messages they have to remove all loops by putting them in a backup state. Now to talk about states there is 5 different states. Two of the five states do not participate in frame forwarding. Frame forwarding is what the three main states do. The three main states are listening, learning, and forwarding. The other 2 are blocking state and disabled state. When you enable the spanning tree protocol the network goes through the blocking state and then the listening state and learning state are enabled after being turned on. If the protocol is properly configured the ports are stabilized to the forwarding or blocking state. The blocking state does not participate in the frame forwarding. It removes frames that are received from the attached segment. It also discards frames from another port for forwarding.
When it comes to getting network traffic from point A to point B, no single way suits every application. Voice and video applications require minimum delay variation, while mission-critical applications require hard guarantees-of-service and rerouting.
Since we are running out of IPv4 addresses, in the future certain websites will only maintain IPv6 and the Internet becomes a dual IPv4/IPv6 network. This means that in order for a user to connect with your customers, co workers, users and to guarantee that your website remains easy to get to all Internet users, in particular in rising markets; you need to make sure you also have IPv6. And that your network and IT personnel are aware and prepared for the changeover. Time is running out. There still will be ipv4 addresses in 2020 or even longer and the devices using those addresses will continue working at the same time but in a improved version IPv6. For operators it will be hard and expensive to get new IPv4 addresses to increase their networks, while the cost of supervision on the existing IPv4s also increases. That is why big companies, such as Face book, Bing and Google, will face the dilemma before end users, because at some time or another they too will need to purchase new servers. Some major internet companies has been known to say that users will not be affected at this time. But the circumstances might not remain the same. The end user may find some sites and email addresses difficult to get to, if they use only IPv6 and user’s service provider only has IPv4 addresses. Taking care of this problem now is the best proactive approach could ask for.
Modern internet technology is introduced into new vehicles as a safety feature. One recent idea is having connectivity between vehicles. Ankeeta Patel of Parul Institute of Engineering and Technology presents the
Whether you've worked in your chosen field for years or are just starting out after graduating from college, looking for a new job is a process that involves resumes, searches, interviews and negotiations. It's important to remember that getting a new (or first) job isn't just a switch that you flip; it's a process that takes time, practice and experience. One of the most important parts of the process is networking.
Despite its simplicity and reliability the bus network does have several limitations. The cable length of the bus is limited due to data loss. Also, a bus network may have performance issues if the nodes are located a...
The next network topology is the Bus topology. Bus topologies consist normally of one backbone or one transport media that all of the nodes are connected to. The linear bus configuration has only two end points and any information being transmitted through the network is received by all of the nodes simultaneously. Although networks based on a bus topology are relatively inexpensive to set up, they do not scale well. When you try to add mor...
At SRM, I was introduced to the true expanse of computer science. Subjects such as Computer Networks, Algorithms, Probability theory, Principles of programming languages and Data Structures piqued my interest as they allowed me to explore my analytical, logical and creative attributes. Computer Networks, in particular, taught me the importance of sharing of information – the first and foremost thing that we care about. Gradually, my tryst with computer networks become intense as I began to explore more and more about their significance and applications in various facets of life: education, social media, research, entertainment, etc. This fascination and exploration led me to do my final year project on mobile ad hoc networks under the guidance of Professor Velmurugan P. It presents a lifetime prediction routing algorithm that maximizes the network lifetime of MANETS by selecting the least dynamic route with long lifetime for maintaining the uninterrupted data flow. Later on, the pap...