Spanning Tree Protocol
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 controlling communications of multiple devices are outlined on defined procedures. Arbitration structures are essential in the control of the bus communications in the presence of multiple devices.
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.
Troubleshooting media problems on a bus networks can be very tedious, since a break in the backbone will bring down the entire LAN. For this reason, bus topology is not considered one of the more robust network topologies, compared with star or mesh. A loose or missing terminating resistor can also bring down a LAN.
Meanwhile, these massive files quickly began monopolizing the services of the central location network switch. Since the network was physically redundant throughout, the network components tried to calculate new paths along which the data could flow; but eventually became confused. Therefore, the redundant components intended to operate in tandem became primary and began to duplicate each other’s functions, resulting in an endless loop until the network was totally disabled. On the afternoon of November 13, 2002, every software application that required network communication abruptly stopped
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.
Alexis Rockman’s “Kapok Tree” was painted in 1995, using oil paints on wood. Being completed near the end of the 20th century, this painting would be categorized as modern art; however, Rockman’s painting is considered a contemporary work of art. In general, contemporary art incorporates the social and cultural events of the time in order to create curiosity, a response, and ultimately open a dialogue on such events. In fact, Rockman’s work typically makes the audience consider, react, and respond to his visual art; he is known to use his paintings to explore environmental issues, such as deforestation and climate change (1). As a matter of fact, deforestation of the Amazon Rainforest was the highest in 1995 (2) and can give an insight to the
Although result suggests the effectiveness of SSTP, more well-defined studies that address the above limitations are required to further solidified the evidence in favour of SSTP. For example, to overcome selection bias, participants of future studies could be recruited through social services reasonable for dealing with families with special needs children. Likewise, issues with self-reports and observations could be circumvented by involving a third-party, for examples, teachers and independent observers. Finally, it is important that future research establish the mechanism(s) through which SSTP functions to obtain its effectiveness, or which session(s) of the program contribute its effectiveness. This is important in terms of resources
In class, we discussed minimum spanning trees (MSTs) and the algorithms that derive MSTs from a graph specification. Using your class notes as a guide, answer the following questions.
A network can be based on either a peer-to-peer level or server-based, also referred to as domain-based. To distinguish the difference, a peer-to-peer network, also known as a workgroup, is a network in which a group of computers are connected together to share resources, such as files, applications, or peripherals. The computers in a peer-to-peer network are peers to one another, meaning no single computer has control over one another. There is also no central location for users to access resources, which means that each individual computer must share their files in order for other computers to have access (Muller, 2003, p.411). “In a peer-to-peer environment, access rights are governed by setting sharing permissions on individual machines.” (Cope, 2002) On the other hand, in a domain-based network, the computers connected together are either servers or clients. All of the other computers connected to the network are called client computers. The server is a dedicated machine that acts as a central location for users to share and access resources. The server controls the level of authority each user has to the shared resources. When logging on to the network, users on client machines are authenticated by the server, based on a user name and password (Lowe, 2004, p.13).
The purpose of this papers it to examine in detail the operation of one of the wide area network that we discussed in class. This paper discusses the difference between frame relay networks and other point to point networks, advantages, addressing schemes, and different protocols supported. The paper will explain virtual circuits briefly before moving to its other characteristics because they are the key to understanding frame relay concept in general. Other than virtual circuits, we will see its addressing scheme, how frame relay guaranty bandwidth with its committed information rate and how to detect and avoid congestion.
TCP/IP is a network model which enables the communication across the Internet. The most fundamental protocol on which the Internet is built. This is made up of the 2 common networking protocols, TCP, for Transmission Control Protocol, and IP, for Internet Protocol. TCP maintains and handles packet flow linking the systems and IP protocol has the ability to handle the routing of packets. However The TCP/IP stack consists of 5 layers first being application layer, the transport layer, then the network layer, the link layer and finally the physical layer. The assignment focuses on the three middle layers and is divided into five parts. Firstly explaining how the TCP and UDP the most vital protocols needed to deliver and communicate.
This essay will argue for an extended role for dialogue and relational communication in public relations practice. The rhetorical turn that public relations has taken over the last ten years as well as the expanded role that public relations practitioners need to play as organizational counsellors is discussed. Several case studies are examined and used to support the arguments for an expanded role of public relations advocacy and management.
Bus topology refers to a local area network (LAN) arrangement where each node or device is connected to a main cable or link called a bus. A bus network is simple yet very reliable. Since nodes themselves are not relied upon for communication, the failure of a single node is not problematic for the rest of the network. For a major issue to occur, there must be a problem with the bus itself.
Local Area Networks also called LANs have been a major player in industrialization of computers. In the past 20 or so years the worlds industry has be invaded with new computer technology. It has made such an impact on the way we do business that it has become essential with an ever-growing need for improvement. LANs give an employer the ability to share information between computers with a simple relatively inexpensive system of network cards and software. It also lets the user or users share hardware such as Printers and scanners. The speed of access between the computers is lighting fast because the data has a short distance to cover. In most cases a LAN only occupies one or a group of buildings located next to each other. For larger area need there are several other types of networks such as the Internet.
In recent years, network coding [1], [2] has been considered as an auspicious information network paradigm for augmenting the throughput of multiple unicast networks [5]. The pioneering researches of network coding were undertaken by R. Ahlswede, N. Cai, S.-Y.R. Li and R.W. Yeung. Their discovery, which was first introduced in [1][2], are considered to be the crucial breakthrough in modern information theory and the time of its appearance, is recognized as the beginning of a new theory-Network Coding theory. In these elegant, succinct articles, within the purview of rigorous mathematics, the glimmering of an optimal network protocol for multiple unicast network was introduced in which the key idea is considering digital information as wave [riis].