NT1210 Lab 3.2. The OSI reference Model
Exercise 3.2.1
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 specific protocols, like TCP, they're "segments" or "datagrams" in UDP. This layer is responsible for getting the entire message to keep track of fragmentation. Session layer is Network Basic Input/output System model allowing applications on separate computers to communicate over a local area network. The Point-to-Point Tunneling Protocol (PPTP) is a method for implementing virtual private networks. PPTP uses a control channel over TCP and a GRE tunnel operating to encapsulate PPP packets. Presentation uses Secure Sockets Layer which provides a secure connection between internet browsers and websites. 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)