I. INTRODUCTION
DTN is fundamentally an intermittent network, where the communication links only exist temporarily, rendering it impossible to establish end-to-end connections for data delivery.
Delay Tolerant Networking (DTN) is a new area of research in the field of networking that deals with extending existing protocols or inventing new ones in a coordinated, architecturally clean fashion, to improve network communication when connectivity is periodic, intermittent and/or prone to disruptions and when multiple heterogeneous underlying networks may need to be utilized to effect data transfers.
The challenges of this field of research are:
1. Large delays (due to physical distances, small bandwidth, or extended disconnection).
2. A second challenge is efficient routing in the presence of frequently disconnected, pre-scheduled, or opportunistic link availability.
3. A third challenge is high link-error rates that make end-to-end reliability difficult.
Finally, heterogeneous underlying network technologies (including non-IP-based internetworks) and application structure and security mechanisms capable of limiting network access prior to data transit are required in environments where feedback may be highly limited.
A. Nodes in a Delay-Tolerant Network
In a DTN, a node is an entity with a bundle layer. A node may be a host, router, or gateway (or some combination) acting as a source, destination, or forwarder of bundles:
• Host—Sends and/or receives bundles, but does not forward them. A host can be a source or destination of a bundle transfer. The bundle layers of hosts that operate over long-delay links require persistent storage in which to queue bundles until outbound links are available. Hosts may optionally support c...
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...s at a slight non-negligible cost, we cannot take chance by allowing the nodes to communicate without any authentication, as the network is wireless, any node (say, malicious) can join a cluster or intercept the transmission range of other valid nodes and then can transmit its’ information. Thus, authentication is also as important as routing.
As a future-work, since all our work was based on a static instance of the Delay Tolerant Network, it has to be extended to dynamic networks in future in-order to gain a better conclusion. Also, based on this dynamic movement of nodes, cluster-head and gateway node has to be selected accordingly, and routing of messages should take place.
Works Cited
Ha Dang, Hongyi Wu, “Clustering and Cluster-Based Routing Protocol for Delay-Tolerant Mobile Networks”, IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS, VOL. 9, NO. 6, JUNE 2010.
Routing protocols for high dynamic topology: the topology of the network is highly dynamic underwater because nodes move passively with water currents. These routing protocols are designed for sensor networks with dynamic topology like UWSNs.
Sending data through the internet efficiently has always posed many problems. The two major technologies used, Ethernet and Asynchronous Transfer Mode (ATM), have done an admirable job of porting data, voice and video from one point to another. However, they both fall short in differing areas; neither has been able to present the "complete" package to become the single, dominant player in the internet market. They both have dominant areas they cover. Ethernet has dominated the LAN side, while ATM covers the WAN (backbone). This paper will compare the two technologies and determine which has a hand-up in the data trafficking world.
TOR (Roger Dingledine) is a circuit based low-latency anonymous communication service. TOR is now in its second generation and was developed from the Onion routing program. The routing system can run on several operating systems and protect the anonymity of the user. The latest TOR version supports perfect forward secrecy, congestion control, directory servers, integrity checking and configurable exit policies. Tor is essentially a distributed overlay network which works on the application layer of the TCP protocol. It essentially anonymizes all TCP-based applications like web-browsing, SSH, instant messaging. Using TOR can protect against common form of Internet surveillance known as “traffic analysis” (Electronic Frontier Foundation). Knowing the source and destination of your internet traffic allows others to track your behavior and interests. An IP packet has a header and a dat...
8) Ian F. Akyildiz, Ismail H. Kasimoglu, “Ad Hoc Networks’’, Wireless sensor and actor networks: Research Challenges, Georgia Institute of Technology, USA, May-2004.
Roberts, Richard M. "Network Secrurity." Networking Fundamentals. 2nd ed. Tinley Park, IL: Goodheart-Willcox, 2005. 599-639. Print.
An Open Shortest Path First (OSPF) protocol is the most used interior gateway protocol and computation intensive protocol where energy consumption in Internet Protocol (IP) networks is the main concern. The energy in an IP network can be saved by allowing a subset of IP router interfaces on sleep mode setting during the low traffic hours through the model of “move” by dint of an Energy Aware Routing (EAR) strategy, which is completely compatible with OSPF and is based on the “Shortest Path Tree (SPT) exportation” techinque or “Dijkstra's Algorithm”. In case of heavy traffic hours, the EAR strategy is not usable and may cause denial of service. The strategy implemented can help a network operator to control the network performance and allow a smoothed QoS degradation. This performance evaluation study permits to save about 30% of network links with a insignificant rise of link loads and network path lengths.
ATM Network can be modeled by an connected graph G(V,E).The performance of the multicast routing in a system can be measured by following criteria.
ABSTRACT : This paper describes the basic threats to the network security and the basic issues of interest in designing a secure network. it describes the important aspects of network security. A secure network is one which is free of unauthorized entries and hackers. INTRODUCTION
...vantage of the overall network design and implement usable subnets with virtual local area networks. Use encryption and encapsulation to secure communications of public segments to enable extranets and cross-Internet company traffic. Use items such as intrusion detection systems and firewalls to keep unauthorized users out and monitor activity. Taken together, these pieces can make a secure network that is efficient, manageable, and effective.
Properly secure wireless systems: - To prevent data breaches it is very important to secure wireless networks. WI- Fi network security is necessary because it is very easy to hack the data and unauthorized access. Breaches can be prevented by using strong passwords, encryption methods, and strong verification.
Hollows, P 2002, 'Essentials of a smooth-running network', Communications News, vol. 39, no. 7, p. 16.
The Internet has revolutionized the computer and communications world like nothing before. The Internet enables communication and transmission of data between computers at different locations. The Internet is a computer application that connects tens of thousands of interconnected computer networks that include 1.7 million host computers around the world. The basis of connecting all these computers together is by the use of ordinary telephone wires. Users are then directly joined to other computer users at there own will for a small connection fee per month. The connection conveniently includes unlimited access to over a million web sites twenty-four hours a day, seven days a week. There are many reasons why the Internet is important these reasons include: The net adapts to damage and error, data travels at 2/3 the speed of light on copper and fiber, the internet provides the same functionality to everyone, the net is the fastest growing technology ever, the net promotes freedom of speech, the net is digital, and can correct errors. Connecting to the Internet cost the taxpayer little or nothing, since each node was independent, and had to handle its own financing and its own technical requirements.
Due to the demand for the internet to be fast, networks are designed for maximum speed, rather than to be secure or track users (“Interpol” par. 1). The adage of the adage.... ... middle of paper ... ...
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...