Windows Server 2003 Or Windows 2000 Server Network Environments

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When sending data, each layer in the OSI model places its own information onto the data as it passes down the stack in a process called encapsulation . Encapsulation takes place when each layer adds its own header and sometimes trailer information onto the data. When the data is received, it works its way back up the protocol stack, and the corresponding layer of the protocol stack reads this information.

The Physical Layer

The Physical layer is responsible for using electric (or sometimes other types of) signaling to get bits from one computer to another. Physical layer components don’t care what the bits mean ; their job is to get the bits from point A to point B, using whatever kind of optical, electrical, or wireless connection that connects the points. This level ccnp exam defines physical and electrical details, such as what will represent a 1 or a 0, how many pins a network connector will have, and when the network adapter can or cannot transmit the data (see Figure 1.2).

The Physical layer addresses all the small details of the actual physical connection ...
... between the computer and the network medium, including the following:

Network connection types, including multipoint and point-to-point connections. Physical topologies, or how the network is physically laid out (for example, bus, star, or ring).

Which analog and digital signaling methods are used to encode data in the analog and digital signals.

Bit synchronization, which deals with a practice exams keeping the sender and receiver in sync as they read and write data.

Multiplexing, or the process of combining several data channels into one.

Termination, which prevents signals from reflecting back through the cable and causing signal and packet errors. It also indicates the last node in a network segment.