Networks are a facet of computing that has gone from an expensive option for the largest organisation, to mainstream standard on the cheapest pcs in an amazingly short time. These days, a pc often seems crippled without some form of network connection, cruise booking a testament to how important networks have become in the industry. In this issue, we’ll talk about how networks function, primarily focusing on the most common standards like ethernet.
T o understand networking, agenzia web marketing roma it helps to have an overall idea of how things are designed. Early networks were often a jumble of whatever worked. But as we moved out of the labs and into the office, things needed to be more organised to aid in troubleshooting and design. So, the International Organisation for Standardization came up with the Open Standards Interconnection model in 1982.
The OSI model consists of seven layers that describe the various functions of a network. They’re numbered 1 through 7, starting at the bottom, ageniza comunicazione bologna and higher layers require lower layers to function before they can function. Thus, troubleshooting a network can be broken down into a series of steps verifying that each later is properly working.
Layer 1 is the physical layer. Basically, the wires that connect the machines together. The specifications, such as voltages, maximum length, types of cables, etc. are specified in the physical layer. The unit of data this layer deals with is bits.
Layer 2 is called the data link layer. This is the layer where low level protocols like Ethernet function. The device to device connections between a PC and a switch, or another PC on the same LAN, are managed here. Layer 2 deals with frames, which are small units of data that contain basic information about source end destination.
Layer 3 is the network layer. Internet Protocol (IP is a layer 3 protocol. This layer deals with packets, which transmit variable length data sequences and are routed to the proper points in the network. Layer 3 is responsible for delivering data to its destination. verified members la
Layer 4 is the transport layer, and where we see the TCP part of TCP/IP. It stands for Transmission Control Protocol. Layer 4 protocols are responsible for sending segments, maintaining connections, controlling the flow of data, and resending data that didn’t arrive or was corrupted in transit. This layer also has the job of reassembling packets into useful data in the correct order.
Layer5 is the session layer and deals with ‘conversations’ of data. It is responsible for initiating and terminating connections between the two applications on the relevant machines.
Layer 6 is the presentation layer, and deals with getting data ready for use in the application. Things such as a compression and encryption are part of this layer. Codecs such as MPEG, cake labs or other systems that manipulate data into a specific useable format are part of this layer.
Layer 7 is the application layer. This layer is closest to the end user and is for protocols that provide the user with a means to access network information for the application. HTTP, FTP, Telnet, and SMTP are all layer 7 protocols.