They are actually reserved circuits within the service provider’s network that connect geographically separated offices for private voice and/or data networking.

An inexpensive option that uses any phone line and a modem. The low bandwidth provided by a dial-up modem connection is usually not sufficient for large data transfer, although it is useful for mobile access while traveling.

Communication standards for simultaneous digital transmission of voice, video, data, and other network services over the traditional circuits of the public switched telephone network.

Provide a high bandwidth, always on, connection to the Internet. It runs over a telephone line.

The availability of satellite Internet access is a real benefit in those areas that would otherwise have no Internet connectivity at all. Satellite dishes require a clear line of sight to the satellite.

Performance will be limited by the capabilities of the phone and the cell tower to which it is connected.

Are wide area networks logically defined over public transmission systems. Used to allow access to only authorized users. Traffic on a it is isolated from other traffic on the same public lines.

Is the kernel of Cisco routers as well as all current Catalyst switches.

It is the central part of an operating system. It manages the tasks of the computer and the hardware - most notably memory and CPU.

Used to configure and maintain the router. Allow root access to the router via terminal interface.

Is the RS-232C interface that a computer uses to exchange data with a modem or other serial device. Terminates flow of information in any communication network.

Transports information over communication medium. It provides functions such as coding, clocking, etc. for the information to be transmitted and received. Generates clock rate.

Defines the speed (in terms of bits/second) to be sent over a given time

Used to hold packet buffers, ARP cache, routing tables, and also the software and data structures that allow the router to function.

Stores the Cisco IOS by default. It is not erased when the router is reloaded.

Allow you to connect to remote devices, change terminal line settings on a temporary basis, perform basic tests, and list system information

Provide advanced testing commands, such as debug.

It is used to configure your system globally, or to enter specific configuration modes to configure specific elements such as interfaces or protocols.

Config. mode to modify the operation of an interface such as an Ethernet or serial port, bandwidth, clock rate, IP address, subnet mask.