Chapter 6: Local Area Networks
Terms
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- What do you call a server operation system?
- Server Network Operating System
- What do you call many servers that are part of a network?
- Server Farm
- What are the 6 basic LAN components?
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1. Clients
2. Servers
3. Network Interface Cards
4. Network Cables
5. Hubs and Switches
6. Network Operating System - What would you use to connect a UTP and a Coaxial Cable?
- BALUN
- What is the most common choice of network cable?
- Untwisted Wire Pairs (UTP)
- What are 3 basic functions of a Hub?
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1. Act as a junction box, linking several computers on a network
2. Connection of more than one type of cable
3. Repeat incoming signals to extend the distance - What are the 2 types of Network Operating Systems (NOS)?
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1. Server NOS
2. Client NOS - What specifies what resources are available to the network for use by other computers?
- Network Profile
- What describes what each user on a LAN has access to?
- User Profile
- What keeps track of which user has accessed what network resource?
- Auditing Software
- What do you call an Ethernet LAN that uses hubs?
- Shared Ethernet
- How does a bus topology work?
- All computers on the network receive messages from all other computers, whether the message was intended for it or not. Each computer can individually accept or reject the message.
- What is ethernet's medium access control protocol?
- CSMA/CD - (Carrier Sense Multiple Access w/ Collision Detect)
- What does the Carrier Sense of the CSMA/CD mean?
- Computers listen to the network to see if another computer is transmitting before sending.
- What is the difference between a switch and a hub?
- A hub sends a message to all computers on the network while a switch reads the destination address and sends the messages specifically to that computer.
- What do you call a switch that makes switching decisions based on data link layer addresses?
- Layer-2 Switches
- What do switches use to decide where to send a message?
- Forwarding Tables
- How does a switch behave when it is first turned on?
- It behaves like a hub. It sends messages to all computers until it learns the addresses of each computer and saves the addresses in its forwarding table.
- Which media access control does switched ethernet use?
- CSMA/CD
- Instead of Hubs, Wireless LANS use...
- Access Points
- What media access control does WLANs use?
- CSMA/CA - where CA stands for Collision avoidance.
- How does the virtual carrier sense method work?
- A request to send (RTS) signal is sent to the access point. If it's free, then it sends back a clear to send (CTS) signal.
- What type of infrared bounces the infrared signal off of walls, so that a direct line of sight isn't needed?
- Diffuse Infrared
- What are the 3 types of wireless ethernet?
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1. Direct Sequence Spread Spectrum (DSSS)
2. Frequency Hopping Spread Spectrum (FHSS)
3. IEEE 802.11a - What is the measure of LAN performance?
- Throughput
- What 2 types of server performance improvements are possible?
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1. Software improvements
2. Hardware Improvements - What is the slowest task a server needs to do?
- Read from the disk
- What is a RAID?
- Redundant Array of Inexpensive Disks
- What are ways to improve LAN performance?
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1. Identify Network Bottlenecks
2. Improve Server Performance - (hardware and software)
3. Improve Circuit Capacity
4. Reduce Network Demand