27-12-2012, 04:37 PM
Exploring the Functions of Networking
Exploring the Functions.ppt (Size: 1.46 MB / Downloads: 31)
Network User Applications
E-mail (Outlook, POP3, Yahoo, and so on)
Web browser (IE, Firefox, and so on)
Instant messaging (Yahoo IM, Microsoft Messenger, and so on)
Collaboration (Whiteboard, Netmeeting, WebEx, and so on)
Databases (file servers)
Impact of User Applications on the Network
Batch applications
FTP, TFTP, inventory updates
No direct human interaction
Bandwidth important, but not critical
Interactive applications
Inventory inquiries, database updates.
Human-to-machine interaction.
Because a human is waiting for a response, response time is important but not critical, unless the wait becomes excessive.
Real-time applications
VoIP, video
Human-to-human interaction
End-to-end latency critical
Characteristics of a Network
Speed
Cost
Security
Availability
Scalability
Reliability
Topology
Summary
A network is a connected collection of devices that can communicate with each other. Networks carry data in many kinds of environments, including homes, small businesses, and large enterprises.
There are four major categories of physical components in a computer network: the computer, interconnections, switches, and routers.
Networks are depicted graphically using a set of standard icons.
The major resources that are shared in a computer network include data and applications, peripherals, storage devices, and backup devices.
The most common network user applications include e-mail, web browsers, instant messaging, collaboration, and databases.
User applications affect the network by consuming network resources.
The ways in which networks can be described include characteristics that address network performance and structure: speed, cost, security, availability, scalability, reliability, and topology.
A physical topology describes the layout for wiring the physical devices, while a logical topology describes how information flows through a network.
In a physical bus topology, a single cable effectively connects all the devices.
In a physical star topology, each device in the network is connected to the central device with its own cable.
When a star network is expanded to include additional networking devices that are connected to the main networking device, it is called an extended-star topology.