Networking Concepts Lesson 03 - Media - Eric Vanderburg

1. Chapter 3
Networking Media
Networking Concepts – Eric Vanderburg ©2005

2. Cable Characteristics
 Bandwidth
Rating
 Max Segment Length
 Segments per network
 Devices per segment
 Interference Susceptibility (EMI & RFI)
 Connection Hardware
 Cable Grade (PVC or Plenum Grade Teflon)
 Bend radius
 Cost (Material, Installation, & Maintenance)
Networking Concepts – Eric
Vanderburg ©2005

3. Signal Degradation
 Reduce
 Do
EMI/RFI
not place copper media next to
 Fluorescent
lights
 Generators/motors
 High-voltage electrical wire
 Proper
installation
 Use quality cable
 Use shielded cabling
 Use repeaters to strengthen signal on long
cable runs
Networking Concepts – Eric
Vanderburg ©2005

4. Transmission
 Baseband
 Digital
 One
channel
 Use repeaters
 Broadband
 Analog
 Multiple
channels
 Use amplifiers
Networking Concepts – Eric
Vanderburg ©2005

5. Coaxial Cable (Coax)
 RG-6
- Used for satellite cable
 RG-8 - Thicknet
 RG-11 – 75 ohm, Thicknet, handle higher power
 RG-58 /U - 50 ohm, with a solid copper wire core.
 RG-58 A/U* - 50 ohm, with a stranded wire core.
 RG-58 C/U* - Military version of RG-58 A/U.
 RG-59 - 75 ohm, for broadband transmission such
as cable TV.
 RG-62 - 93 ohm, primarily used for ArcNet.
Networking for Ethernet networks
*Only these are part of the IEEE specificationConcepts – Eric
Vanderburg ©2005

6. Coaxial Cable (Coax)
 Thicknet
(10base5)
½ inch thick
 RG-11 or RG-8
 Vampire tap
 AUI (Attachment Unit Interface) - 15 pin DB-15

 Thinnet
(10base2)
BNC (British Naval Connector)
 50 ohms impedance
 RG-58

 Coax
for Broadband (RG-59, 75 Ohm)
Networking Concepts – Eric
Vanderburg ©2005

7. Twisted Pair
 Twists
reduce crosstalk
 UTP (Unshielded Twisted Pair) 10baseT
 STP (Shielded Twisted Pair)
 Foil
wrapped around wires
 Phone
line (RJ-11)
 TP Network cable (RJ-45)
 100 Meter max length
Networking Concepts – Eric
Vanderburg ©2005

8. Twisted Pair Categories








Cat1 – voice only, before 1982
Cat2 – 4 wires, 4Mbps
Cat3 – 4 wires, 10Mbps, 3 twists/foot
Cat4 – 8 wires, 16Mbps
Cat5 – 8 wires, 100Mbps
Cat5e – 8 wires, 1Gbps, full-duplex
Cat6 – 8 wires, 1Gbps
Cat7 – 8 wires, shielded, 1Gbps
*AWG (American WireNetworking Concepts22, Eric 26. Specifies wire type.
Gauge) – Telephone is usually – 24, or
Vanderburg ©2005

9. Other Hardware
Wall Plate
Patch Panel
Networking Concepts – Eric
Vanderburg ©2005

10. Fiber Optic
 Signal
sent by light
 No eavesdropping
 No interference
 Two cables needed for full duplex
 Surrounded by kevlar
 Max length: 2-100 km
 1Gbps & 10Gbps implementations
 Difficult to install
 Expensive (Cable, Install, Maintenance)
Networking Concepts – Eric
Vanderburg ©2005

11. Fiber Optic Connectors
ST (Straight Tip)
LC (Link
Control)
SC (Straight Connection)
MT-RJ
two cables in one
RJ-45 clone
MIC (Medium Interface Connector)
SMA (Subminiature Type A)
Networking Concepts – Eric
Vanderburg ©2005

12. Fiber Optic cable types
 Single
mode
Laser based
 Spans longer distance
 One piece of glass
 Core: 2-9 microns

 Multi-mode
LED based
 Shorter distance
 Multiple pieces of glass
 Core: 25-200 microns

View Cables and prices at: http://www.cableorganizer.com/fiber-optic-jumpers/fiber-optic-multimode50.htm
Networking Concepts – Eric
Vanderburg ©2005

13. Quick Comparison
Type
Length
Bandwidth
UTP
100 meters
10Mbps-1Gbps
Easy
High
Cheapest
STP
100 meters
16Mbps-1Gbps
Moderate
Moderate
Moderate
Thinnet
185 meters
10Mbps
Easy
Moderate
Cheap
Thicknet
500 meters
10Mbps
Hard
Low
Expensive
2-100 kilometers
100Mbps-10Gbps
Moderate
None
Most
Expensive
Fiber
Installation Interference
Networking Concepts – Eric
Vanderburg ©2005
Cost

14. Cabling Concerns
 Differing
bandwidth requirements
 Building and Fire codes
 Existing setup
 Budget
 Upgradeability, Obsolescence, & TCO
Networking Concepts – Eric
Vanderburg ©2005

15. Wireless Uses
 Temporary
connections
 Redundant connections
 Network extension
 Roaming
 Access in difficult areas
 Support for handhelds
 Docking
 Peripherals
Networking Concepts – Eric
Vanderburg ©2005

16. Wireless Networks
 LANs
– 802.11a,b,g
 Extended LANs – Microwave, Satellite
 Mobile – Radio or Cellular
 Provided
by communications carrier
Networking Concepts – Eric
Vanderburg ©2005

17. Electromagnetic Fundamentals
 Lower
frequency = slower, less data,
longer distance
 Higher frequency = faster, more data,
shorter distance
 Highest frequencies need line of sight &
use tight beams
Networking Concepts – Eric
Vanderburg ©2005

18. Frequency Ranges
 Radio:
10KHz – 1GHz
 Microwave: 1GHz – 500GHz
 Infrared: 500GHz – 1THz
Networking Concepts – Eric
Vanderburg ©2005

19. Infrared Technologies
 Line
of Sight
 Reflective (central device)
 Scatter Infrared
 Bounces
signal
 Limited to 30 meters
 Broadband
Optical Telepoint Networks
Networking Concepts – Eric
Vanderburg ©2005

20. Infrared Transmission

Diffused



Directed



The infrared light transmitted by the sender unit fills the area.
The receiver unit located anywhere in that area can receive
the signal.
The infrared light is focused before transmitting the signal
Increases the transmission speed.
Directed point-to-point


Highest transmission speed
Receiver is aligned with the sender unit. The infrared light is
then transmitted directly to the receiver.
Networking Concepts – Eric
Vanderburg ©2005

21. Laser Technologies
 Requires
line of sight
 Not vulnerable to visible light
interference
Networking Concepts – Eric
Vanderburg ©2005

22. Radio LAN Technologies
 Narrow
Band
 Devices use known single frequency
 Unregulated bands (902-928MHz,2.4GHz,5.72-5.85GHz)
 No line of sight needed
 Range of 70 meters
 Possible to eavesdrop
 High susceptibility to RFI
Networking Concepts – Eric
Vanderburg ©2005

23. Radio LAN Technologies
 High
powered technologies
 Long
range to horizon
 Towers used to redirect signal
 Much more expensive
 FCC licensing required
Networking Concepts – Eric
Vanderburg ©2005

24. Spread Spectrum Technologies
 Uses
multiple frequencies
Less interference
 Redundancy

 Frequency
Range: 902-928MHz,2.4GHz
 Frequency Hopping
Changes at regular intervals
 Lower bandwidth, more secure

 Direct-sequence
Modulation
Send different data chunks along multiple
frequencies
 Low frequencies (just above noise)

Networking Concepts – Eric
Vanderburg ©2005

25. 802.11
 802.11a
 802.11g
 54Mbps
 54Mbps
 5GHz
 2.4GHz
 WPA
 802.11b
 11Mbps
 802.11i
 2.4GHz
Support
 WPA
& other
encryption Support
 802.11e
 802.11n
 QOS
 300Mbps
 2.4GHz
*WPA (Wi-Fi Protected Networking
Access)
Concepts – Eric
Vanderburg ©2005

26. Ad Hoc Wireless


Broadcasting/Flooding
Suppose that a mobile user A wants to send data to
another user B in the same area. When the packets
containing the data are ready, user A broadcasts the
packets. On receiving the packets, the receiver checks
the identification on the packet. If that receiver was not
the correct destination, then it rebroadcasts the
packets. This process is repeated until user B gets the
data.
Temporary Infrastructure
In this method, the mobile users set up a temporary
infrastructure (mapping). But this method is
complicated and it introduces overheads. It is useful
only when there is a small number of mobile users.
Networking Concepts – Eric
Vanderburg ©2005

27. Wireless
 BSA
(Basic Service Area)
 Influence
of the WAPs
 Depends on:
 Power
of the transmitter
 Environment
 BSS
(Basic Service Set)
 Stations
belonging to an AP
Networking Concepts – Eric
Vanderburg ©2005

28. Wireless Extended LANs
 Connects
LAN segments
 Eliminate leased line costs
 10x cost of leased line
 Work in pairs “half-repeaters”
 Optical
Half-repeaters
 Radio Half-repeaters
Networking Concepts – Eric
Vanderburg ©2005

29. Wireless Extended LANs
 Short
Range
 1-3
miles
 1-6Mbps
 Spread Spectrum
 Long
Range
 Up
to 25 miles
 2-100Mbps
 Infrared or Laser
Networking Concepts – Eric
Vanderburg ©2005

30. Microwave Networking
 Higher
transmission than radio
 Line of sight
 FCC approval
 RF Hazard Assessment
(determine RF levels at a site)
 Motorola's WLAN product (ALTAIR)
 Uses
low powered microwave radio signals
 18GHz
Networking Concepts – Eric
Vanderburg ©2005

31. Microwave Networking
Terrestrial microwave
 Between 2 locations
 Relay towers to cover long distances
 4-6GHz or 21-23GHz
 1-50 miles
 10Mbps
 Vulnerable to weather disturbance
 Satellite microwave
 Propagation delay
 Must have or lease a satellite
(gov’t approval, expensive)
 Global
 Easy to eavesdrop
 11-14GHz
 10Mbps
 Vulnerable to EMI, Jamming, and weather

Networking Concepts – Eric
Vanderburg ©2005

32. 802.16a Wireless MAN
 WiMax
(Worldwide Interoperability for
Microwave Access)
 70Mbps
 30 miles
 Moving car access
 Broadband to distant locations
Networking Concepts – Eric
Vanderburg ©2005

33. More Microwave technology
 CDPD
(Cellular Digital Packet Data)
 19.2kbps
 Handheld
 Low
connections
orbit satellites
 10bps
 Continental
coverage
Networking Concepts – Eric
Vanderburg ©2005