Introduction In the OSI model of computer networking, the data link layer is layer two of seven and corresponds to the host-to-network layer of the TCP/IP reference model. Its main aim is to reliably transfer data between two adjacent machines whilst efficiently detecting and correcting errors in transmission. Packets from the network layer are packed into frames and transferred to the network layer on another machine. Data link layer protocols respond to the network layer and issue requests to the physical layer. The data link layer in LANs can contain Media Access Control and Logical Link Control sub-layers. Unacknowledged connectionless service can be offered by the data link layer. It is used in LANs and other reliable mediums or real-time traffic situations. No connection is established when the source machine sends individual frames to a machine, frames are not acknowledged. Acknowledged connectionless service works on the same principles as unacknowledged connectionless service except each individual frame is acknowledged on reception. It is used on unreliable media such as wireless. Acknowledged connection-oriented service is also provided by the data link layer, data is sent and acknowledged. The data link establishes a connection to send data then releases it once the data has been successfully sent. Framing In order to transfer data between layers, a bitstream is split into frames containing the frames source and destination information. Errors can occur during transmission of frames which are rectified using a suitable protocol. Frames are transferred between LAN devices by the data link layer. A frame contains a header which includes the source and destination address of the frame. Frames are delivered using... ... middle of paper ... ...evel messages into frames. Sent data needs to be checked for errors when using some protocols and the data link layer monitors and corrects errors that occur on lower levels of the network. Works Cited Carter, N. (2009). What is layer 2 and why should you care?. Available: http://www.accel-networks.com/blog/index.php?q=/2009/09/what-is-layer-2-and-why-should-you-care.htm. Last accessed 23 March 2010. Kozierok, C M. (2005). Data link layer (layer 2). Available: http://www.tcpipguide.com/free/t_DataLinkLayerLayer2.htm. Last accessed 18 March 2010. whatIs.com. (2009). Data link layer. Available: http://searchnetworking.techtarget.com/sDefinition/0,,sid7_gci211899,00.html . Last accessed 20 March 2010. Yang, S (2009). CO2017 lecture notes. Leicester: University of Leicester. 53-63. Yang, S (2009). CO2017 lecture slides. Leicester: University of Leicester. 57-74.
Multiplexing will gather the data from the source host and give that data some header information. This data will be created into segments by demultiplexing and then be sent to the 3rd layer (Network layer). So to summarize multiplexing will gather data and give it header information and demultiplexing will create segments and sent them to the network layer. Now with flow control that will relate with multiplexing, mainly because it can take multiple data streams and combine them into one shared stream, making that a form of data flow control. Now as far as error checking that will relate to the frames of the data. The logical link control will use a frame check sequence (FCS) to check the frame to see if there is any problems with it. If it detects an error during the frame check sequence then the frame will be discarded and the data will be passed on to the network layer. With this all being said this will mainly be used in the OSI model since the logical link control is the sub-layer for the data link layer. (The other sub layer being MAC) Without the logical link control or 802.2 then the data link layer wouldn’t function
MAC Layer Connections: Management connections and data transport connections are two connections in this layer. The management connections have three types: basic, primary, and secondary. A basic connection and primary connection are created for each MS when they join the network. A basic connection is used for short and urgent management message. And a primary connection is used for delay-tolerant management messages. The secondary connection is used for IP summarized management messages such as dynamic host configuration protocol [DHCP], and simple network management protocol [SNMP]. Transport connections can be provisioned or can be recognized on demand. They are used for user traffic flows. Unicast or multicast can be used for transmission.
Information and Software Technology Years 7–10: Syllabus. (2003, June). Retrieved April 10, 2014, from http://www.boardofstudies.nsw.edu.au/syllabus_sc/pdf_doc/info_soft_tech_710_syl.pdf
It also provide MAC addresses. Every MAC address is unique and it belongs to that particular device. The data link layer is responsible for the means to send out data over the physical layer (Tetz, 2011). Without the data link layer of the OSI devices would not have this unique address that identifies them, as well as not having a means to send out data of the physical layer. The Physical and Data Link layer walk hand in hand in the OSI Model and cannot work without the other.
Last phase is data exchange. In data exchange, client and server exchanges the data by creating one or more data channels. In each channel, flow is control using window space available. There are 3 stages of the life of the channel: open channel, data transfer and close channel. One the channel is open by either of the party, data is transferred and then channel is closed by either of the party [3].
Secondly, the seven layers proposed by OSI are completely out of touch with reality. The defacto networking standard is TCP/IP. TCP/IP is the grandaddy of XNS, IPX/SPX, Banyan, AppleTalk, and a host of other protocols and pre-dates that seven layer thing because it was funded by the largest organization in the world devoted to maintaining Eurocentric socioeconomic domination; the US Military. And for some reason, that makes it better. Yeah.
Ethernet is a household of processor interacting machineries for local area networks. Ethernet was brought to light in 1980 and consistent in 1983 as IEEE 802.3. Ethernet has basically substituted rival online local area network machineries such as token ring, FDDI, and ARCNET. The Ethernet ethics include some cabling and beckoning alternates of the OSI physical layer in use with Ethernet. The unique 10BASE5 Ethernet recycled coaxial cable as a collective medium. Well along the coaxial cables remained exchanged with twisted pair and fiber optic contacts in combination with hubs or switches. Figures rates stood sporadically increased from the innovative 10 megabits per second to 100 gigabits per second. Structures talking across Ethernet split a brook of info into smaller parts called frames. Each frame held basis and endpoint discourses and error-checking information so that dented data can be perceived and re-transferred. As per the OSI model Ethernet delivers amenities up to and counting the info connection layer. Meanwhile its profitable announcement, Ethernet has booked a great grade. Landscapes such as the 48-bit MAC statement and Ethernet frame arrangement have prejudiced other interacting protocols.
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.
A network computer or data network is a telecommunications network that allows computers to exchange data. In computer networks, networked computing devices transmit data to each other using data connections. These connections are established with nodes using either cable or through wireless media. The most famous and interesting computer network is the internet network. There are many types of computer networks, local area networks (LANs) to wide area networks (WAN) campus area networks ( containers ) metropolitan area network MAN ) and home area networks (HANs). With massive uprising in pc’s in the early eighties, the LAN system expanded rapidly. The LAN system on a workstation can be functioned via a short networking cable. LANs consist of computer units linked to a control computer called server. Network technology is the way by which the numerous stations are linked with one another. LAN can be linked to greater networks including mainframe. This provides LAN users with the access to enormous computing power and excellent communication facilities. Computerization in the banking system is the best example of the network LAN.
This report will describe the two forms of data communications in terms of the physical interfaces and modes of operation. It will describe the features of data communications equipment in relation to synchronous and asynchronous communication including modems, network terminating units and sending and receiving equipment.
Internet Protocol version 4 is the current standard “IP” protocol used with Transmission Control Protocol/Internet Protocol (TCP/IP), which is the protocol for Internet addressing. Like the Open System Interconnection (OSI) model, TCP/IP has its own model. The TCP/IP network model represents reality in the world, whereas the OSI model represents an ideal. The TCP/IP network model has four basic layers. The first layer, Network interface layer, deals with all physical components of network connectivity between the network and the IP protocol. Next the Internet layer contains all functionality that manages the movement of data between two network devices over a routed network. Then the Transport layer manages the flow of traffic between two hosts or devices, ensuring that data arrives at the application on the host for which it is targeted. And last, the Application layer acts as final endpoints at either end of a communication session between two network hosts (Tetz).
LAN is used to share resources such as files, printers, games and other application between clients and also...
One of the most basic types of topologies is Point to Point, where a connection between two nodes is established just to communicate between the two. One of most basic examples of this is a two tin can’s on a string; they are connected to each other just so the two can communicate. This relationship can also be observed with two computers connected with a crossover Ethernet cord. This method of connection is also used for communication through telephone, but this is achieved logically. Switched telecommunications systems are used to create a link between two phones to connect them and allow communications between the two and then dropped when the connection is no longer needed. Point to Point communication in modern times is still prevalent, but achieved using more complex networks with the help of logical networking, and can be used to describe many of the connections between individual parts of a network.
...s to translate the packet back into meaningful form and utilize it with suitable application.