An OSI is a model made up for seven different layers starting from the top down, basically what an OSI does is it breaks down its seven layers and different components to make it easier to work with, it controls how network systems communicate to each other. This model is used to help determine what the problem is in a networking community. For example, each layer represents its own function. The physical layer is all of the physical things that connect with each other, like the wires.
Layer 7 (The Application Layer): This layer is what the user interacts with, like Google Chrome, Safari, and Firefox. This application is how things look.
Layer 6 (The Presentation Layer): ...view middle of the document...
This is a common error if the cables and panels aren’t connected. Usually 90% of the problems in an OSI are from the physical layer.
In layer 7 there are several different protocols that are used. FPT is the first; this is used in a FTP client. Next is HTTP and this is used in a web browser. Next is POP3 and SMTP, they are used in email clients. Finally there is Telnet which is the original internet used in 1969 and it is used for the user to help them access sites.
In layer 6 there aren’t specific protocols for this layer. But there are some that work with it that are from the top 3 layers. For example; JPEG, this is used for photos. Next there is MIDI, this is used for music. Also there is MPEG; this is used for the coding of motion video for CD’s. Lastly, QuickTime, this is used to manage audio and video.
In Layer 5 connects in with the top two layers, it uses Full-duplex which is simultaneous two-way connections. Half-duplex which is a two-way communication but it isn’t simultaneous. And finally Simplex which is a one way communication.
In layer 4 uses the connection-oriented protocol which needs a connection with specific agreed upon parameters before the data is sent. Also, segmentation and sequencing, this is when data is segmented into smaller pieces for transport, there is a sequence number with each segment. Next is the connection establishment, this is where connections are established and maintained. Also, there are acknowledgments, which is where a receipt of data is confirmed. And finally, flow control, where controls how fast things are transferred.
Layer 3 uses the most common protocols in my opinion. The first is the Internet protocol, this holds the control and address information so packets can be routed. This is the most common protocol out there. Also the Internetwork Packet Exchange (IPX) this protocol is probably almost entirely deprecated. This interconnects networks that use Novell’s clients and servers.
Layer 2 uses the Spanning Tree protocol; this is used as a loop free typology for bridges Ethernet LAN’s. Virtual LAN is another protocol; this is used to create multiple distinct broadcast domains. This protocol is used with a management protocol to assure that it is working. Finally is Layer 2 Multicast which is used to support multiple registrations.
Layer 1 uses ADSL, which helps push faster data transmission. Next is ISDN which is used for digital transmission for audio, video and data. SDH is also another, this transfers multiple digital bit streams over optical fibers using lasers. Finally, there is RS-232, this works with serial binary single-ended data and controls signals from DTE and DCE.
Layer 2 works with layer 1 and 3. Layer 1 is the key to all of this, layer one is all of the parts that are put together in order to make this system...