NT1210 Lab 3.2. The OSI reference Model
Using Figure 3-1, define each layer of the OSI model in your own words and state what each layer provides. Use your textbook or Internet research to support your answer.
The Physical layer is something simple like wiring, fiber and network cards. Devices that allow communication between the OSI networks. Data link layer is the Ethernet, among other protocols; we're keeping this simple remember. The most important take-away from layer 2 is that you should understand what a bridge is. Switches, as they're called nowadays, are bridges. Network layer is an IP address because you're dealing with layer 3 and "packets" instead of layer 2's "frames." IP is part of layer 3, along with some routing protocols, and ARP (Address Resolution Protocol). Transport layer handles messaging units which is also called packets. When you're talking about ...view middle of the document...
Allowing you to transmit private data online. Also uses Transport Layer Security (TLS) and its predecessor, Secure Sockets Layer (SSL), are cryptographic protocols designed to provide communications security over a computer network. Application layer uses protocols such as SMTP, DNS and FTP. Simple Mail Transfer Protocol (SMTP) is an Internet standard for electronic mail (email) transmission. The Domain Name System (DNS) is a hierarchical distributed naming system for computers, services, or any resource connected to the Internet or a private network. File Transfer Protocol (FTP) is a standard network protocol used to transfer computer files from one host to another host over a TCP-based network, such as the Internet.
Using Figure 3-2 as a basis, complete the diagram to show the intermediate encapsulation provided by each layer. Use your textbook and Internet research to support your answer.
Transport=Segments Network=Packets Data Link=Bit or Frames.
Briefly explain the de-encapsulation steps in the communication from host B receiving a message from host a destined for an active application.
Host A sends a message to host B by using an application first. Secondly it is transported though the TCP/IP header and from there the network receives IP header and TCP/IP header though a switch or router. Then sends it though the (MAC) layer and the Logical Link Control (LLC) layer by using fiber or cable to host B. Now host B receives the MAC layer and LLC layer though the router or switch. Which sends the IP header and the TCP/IP header to an application that host B receives.
Explain why routing devices do not need the upper layers of the OSI model to route traffic. What is the highest layer of the OSI model used by the router to decide where to forward traffic?
Router is a Layer 3 (Network Layer) device that checks packet's IP Address at input interface & routes them to interface connected to destination network if available. That is all it does is forward packet’s, IP Addresses etc. though the OSI model network.