1 / 10

Networking

Networking. What are File Servers?. Network – a group of two or more computers connected together for exchanging data/information and sharing resources File Server – centralized computer used for storing (and sharing) programs and files.

Sharon_Dale
Download Presentation

Networking

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Networking

  2. What are File Servers? • Network – a group of two or more computers connected together for exchanging data/information and sharing resources • File Server – centralized computer used for storing (and sharing) programs and files. • Examples: Database server, Web server, mail server, general file servers • Client-server • Client – computer that ‘receives’ data • Server – computer that provides services to a client

  3. Message • A communication that is transferred from one node on a network to another. • E-mail • Web Pages • FTP (File Transfer Protocol)

  4. Networks • Bandwidth • Amount of data that can be transmitted across transmission medium in a certain amount of time • Packet • Data (Web pages, e-mail messages, etc.) is transmitted in bundles called packets • Header • Sender’s IP address • Receiver’s IP address • Protocol • Packet Number • Data

  5. Expansion of Networks • Variations in degree to which networks are used • Busy during day, quiet at night • To keep demand low on networks, many organizations maintain separate small networks and connect those networks

  6. Expansion of Networks • Pass messages between networks The Internet PC PC Switch PC Router PC Switch PC PC

  7. Firewall – Guard Against External Threats • Acts as a barrier between your system and outside world • Ports provide application-routing information for every message • 21 (FTP) • 25 (E-mail) • 80 (HTTP) • 12345 (NetBus – Trojan) *Block* • Firewall screens ports • Norton Internet Security • McAfee Internet Security • Windows XP (blocks only incoming traffic)

  8. Wireless Technology

  9. Wireless Technology • Access Point • Computer connected to the Internet (acts as intermediary) • Name is SSID (example: RoyalAir, RoyalGuest) (to broadcast or not to broadcast?) • Microsoft's Answer • Usually users able to configure security features • Wireless Router– attaches to access point computer • Beacon • Repeating of identifying information by access point • Example: on a 2.4 GHz radio frequency band • Association – Portable wishes to make connection • Radio waves or infrared signals used to communicate with access point • As portable computers move, interact with new access point • If no computers have direct access to the Internet, portable computers still can interact with each other, but not with the Internet

  10. Wireless Technology • Wireless communications • Messages are divided into packets • Packet contains a header • IDs which machine is to receive the data • Infrared signals or radio waves • All wireless computers in an area share the airwaves, receive the same messages and determine if they are the recipient • 802.11b (11 Mbps max. data rate) • 802.11g (54 Mbps max. data rate) • 802.11n (600 Mbps max. data rate) • Maximum range: varies – about 300 feet • Indoor range less than outdoor (less interference) • Bluetooth (1-3 Mbps DTR / range 10 meters)

More Related