Justin

Physical (Layer 1)

This layer conveys the bit stream - electrical impulse, light or radio signal -- through the network (Links to an external site.) at the electrical and mechanical level. It provides the hardware (Links to an external site.) means of sending and receiving data on a carrier, including defining cables, cards and physical aspects. Fast Ethernet (Links to an external site.), RS232 (Links to an external site.), and ATM (Links to an external site.) are protocols (Links to an external site.) with physical layer components. Hubs and repeaters both work at the Physical layer of the OSI model. also the nic works in this layer as well because it connects physical things together. network switches also work on this layer people use switches instead of hub now so that the info dont have to go through all the computers that are connected to the hub before it reaches they computer.

Data Link (Layer 2)

At this layer, data packets are encoded (Links to an external site.) and decoded into bits. It furnishes transmission protocol (Links to an external site.) knowledge and management and handles errors in the physical layer, flow control and frame synchronization. The data link layer is divided into two sub layers: The Media Access Control (MAC (Links to an external site.)) layer and the Logical Link Control (Links to an external site.) (LLC) layer. The MAC sub layer controls how a computer on the network gains access to the data and permission to transmit it. The LLC layer controls frame synchronization (Links to an external site.), flow control and error checking. the nic works in this layer because it has an ip address.

- Layer 2 Data Link examples include PPP, FDDI, ATM, IEEE 802.5/ 802.2, IEEE 802.3/802.2, HDLC, Frame Relay,

Network (Layer 3)

This layer provides switching (Links to an external site.) and routing (Links to an external site.) technologies, creating logical paths, known as virtual circuits (Links to an external site.), for transmitting...