1. ITS 629: Computer Network Design
Instructor Information: Mark Jamil

2. Network Cabling There are many different types of Ethernet cable.
Max Speed
Length
Cat5
100Base-TX
Cisco - “Fast Ethernet”
100 Mb/s
100 m
Cat5e
1GBase-TX
1 Gb/s
Fiber (850nm/50μm)
1GBase-SX
550 m
Fiber (1300nm/9μm)
1GBase-LX
2000 m
Cat6
10GBase-T
10 Gb/s
Cat6a
10GBase-LW
Cat7a
40GBase-T
100 Gb/s
50 m
100GBase-T
15 m
Fiber (1550nm/9μm)
100GBase-ZR
80,000 m

3. Fiber vs Copper vs. Copper Pair Fiber
Short Distance, usually up to 100m (sort of)
Long Distance, up to 80km (so far)
Can provide power
No Current
Interference (crosstalk) and signal loss
No electricity
Cheaper
Expensive and can be confusing

4. Wireless?
Wireless is a good technology but suffers from inherent problems.
Collisions – Interference between signals on the same frequency.
Works at half duplex.
Limits the number of connections you can make.
Many devices can interfere with signals.
A microwave frequently interfere with 2.4Ghz signals.
Other people working on same frequency is a problem.
Security
Anyone in the area or path can capture your wireless communication and use it to decrypt your data.
Attenuation (signal loss)
For wireless, signal loss related to square of the distance.

5. Copper Ethernet Wires Straight Through Cable Cross-Over Cable
In general, we use two standards when making Ethernet wires.
568A – Colors arranged as such
WG, G, WO, Bl, WBl, O, WBr, Br
568b – Colors arranged as such
WO, O, WG, Bl, WBl, G, WBr, Br
Straight Through Cable Cross-Over Cable

6. Cross-Over vs. Straight Through
Straight through cables connect:
PC to Switch
Switch to Router
Cross over cables connect:
PC to PC
Switch to Switch
Router to Router
PC to Router
In the real world, many devices have something called auto-negotiation (aka auto-MDIX).
These devices can figure out what type of cable you are using.
Do not assume this is always true!

7. Serial Interfaces? In the old days, these were faster than 10Base-T
Speed depends on clock rate and bandwidth
Fastest I have seen is about 50Mb/s
Cables were very expensive compared to copper
Cisco recommends 8Mb/s max on serial.

8. Cisco Modules vs. WIC’s WIC MODULE
In GNS3 you probably noticed that you can add modules and something called WIC’s to your router.
Network Modules
NM or NME
Large interface cards
WAN Interface Card
WIC or HWIC or EHWIC
Small interface cards
WIC
MODULE