Network Devices

Question 1

HUB

Answer 1

• Multi-port repeater
  
  • Traffic going in one port is repeated to every port
• Everything is half duplex
• Becomes less efficient as network speeds more
• 10 megabit / 100 megabit

Question 2

Switches

Answer 2

• Bridging done in hardware
  
  • Application - specific integrate circuit (ASIC)
  • Forwards traffic based on data link address
• Many ports & features
  
  • The core of an enterprise network
  • May provide power over Ethernet (POE)
• Multi-layer switch
  
  • Include router functionality

Question 3

Router

Answer 3

• Routes traffic between IP subnets
  
  • Make forwarding decisions based an IP address
  • Routers inside switches sometimes called layer 3 switch
• Often connects diverse network types
  
  • LAN
  • WAN
  • Copper
  • Fiber

Question 4

Wireless Access Point

WAP

Answer 4

• Not a wireless router
  
  • A wireless router is a router and a WAP in a singe device
• WAP is a Bridge
  
  • Extends the wired network on wireless network
  • Makes forwarding decisions based on MAC address

Question 5

Modem

Answer 5

• Modulator / Demodulator
  
  • Converts analog sounds to digital signals
• Uses standard phone lines
• POTS modems now used for backup & utility function
• ADSL used for internet access

Question 6

Firewalls

Answer 6

• Filters traffic by TCP or UDP port number
• Can encrypt traffic into / out of the network
• Can proxy traffic
  
  • A commonly used security technique

-Most firewalls can be routers

Question 7

Patch Panels

Answer 7

-Combination of punch - down blocks & RJ45 connectors

• Runs from desk are made once
  
  • Permanently punch down to patch panel
• Patch panel to switch can be easily changed
  
  • No special tools
  • Use existing cables

Question 8

Copper Line Drivers and Extenders

Answer 8

• Extend the range of copper wire
  
  • Well beyond normal
• Serial links , copper Ethernet
  
  • Used inside data centers
• Powered device
  
  • Regenerates the signal

-Troubleshooting = No power / no signal

Question 9

Power - Line Communication

PLC

Answer 9

• Power-line communication (PLC)
  
  • Marketed as Ethernet over Power (EoP)
  • IEEE Standard 1901
• 500 Megabits per second
  
  • Standard include links to the premise
  • Intra building networking
  • Vehicles
  • Smart energy drives

Question 10

Power over Ethernet

Answer 10

-Power provided on an Ethernet cable

• Power provided @ switch
  
  • Built-in power - Endspans
  • In-line power injector - Midspans
• Power Modes
  
  • Mode A - Power on the data pairs
  • Mode B - Power on the spare pairs