| A | B |
|---|
| Physical | Deals with Network media and hardware devices |
| Datalink | Organizes bits of data from the physical layer |
| Network | Combines frames from data link layer into packets |
| Transport | Assembles outgoing packets into their proper sequence and checks for errors |
| Session | Maintains a session (connection) between two nodes on the network |
| Presentation | Translates data sent by the application layer into the proper format for lower layers |
| Application | Provides an interface for network-aware applications to use the network |
| UTP | Unshielded Twisted Pair Cable |
| Unshielded Twisted Pair | Consists of one or more pairs of insulated copper wired; each pair is twisted together to avoid crosstalk |
| UTP Categories 1 and 2 | Used for voice-grade communications and low-speed data (1-4Mbps) |
| UTP Category 3 | Minimum requirement for networking |
| UTP Category 4 | Supports speeds up to 16Mbps |
| UTP Category 5 | Supports speeds up to 100 Mbps |
| Advantages: UTP Cable | Inexpensive compared to other cable types |
| Disadvantages: UTP cable | High level of attenuation;transmission distances limited to 100 meters |
| STP cable | Consist of one or more pairs of insulated copper wires, twisted together to avoid crosstalk |
| Coaxial cable | Consist of a single thick conductor surrounded by insulator and a shield |
| Advantages: Coaxial cable | Less expensive than Category 5 UTP |
| Disadvantages: Coaxial cable | More expensive than Category 3 UTP |
| Routable Protocols | TCP/IP; IPX/SPX; Apple Talk |
