1. An overview of the major components
Networking
An overview of the major components

3. Names Your computer (in front of you) is the local host
You access “stuff” on remote computers, called servers; your computer becomes a client
Servers have different roles: web server, video server, file server, etc

4. Issues
How will each computer be identified? How will you control who talks and when?
What kind of wire? How many wires in cable? What type of connectors?
When two PCs access one file, what happens?
How can access to data and peripherals be controlled?

5. The parts
We need a client; a PC that is requesting information or services
We need a Network Interface Card (NIC)to identify client; a way to break files into packets for transmission and reassemble packets
We need wire/cables or some method to get data from point A to point B
PC Operating System has to understand and communicate over the network
We need a server

6. Topologies

7. Frames and NICs
Data is moved in frames, much as you would move your belongings in boxes between apartments
Every NIC has a Media Access Control address (MAC) that is unique; 48-bits long as 12 hex characters
Frame
MAC to
MAC
from
Data
CRC

8. Hardware Protocol Network Technology
Defines the packet type
Defines cabling and connectors used
Defines everything necessary to get data from one computer to another
We have two: Ethernet and Token Ring

9. Ethernet Mid-70’s by Digital Equipment, Intel and Xerox
Dominant standard, thanks to Internet
Three versions: coaxial, unshielded twisted pair and fiber optic
Because frame type is constant, versions can be mixed on the network

10. Token Ring Developed by IBM
Centered on communication with mainframe systems
Completely incompatible with Ethernet
Used to connect to IBM’s “Big Iron” systems and thus is far from dead
More on this later

11. UTP Ethernet 10BaseT, or 100BaseT, or 1000BaseT
10-, 100-, 1000Mbps (1 Gbps)
Uses a star bus topology, typically
Use Unshielded Twisted Pair (UTP) cable (4 pairs = 8 wires)
Connect to Hub (or Switch) which contains the bus
One PC per segment; 100 meters per segment

12. CAT levels
What Mike does not tell you is that the number of twists per inch/foot
Of cable increase as the CAT level increases

13. EZ-RJ-45 has holes here so wires stick out during assembly1
Wiring Standards 8
EZ-RJ-45 has holes here so wires stick out during assembly

14. More on cabling
The space up in the false ceiling, in walls and under a raised floor is called a plenum space
You should run plenum (non-toxic) cable in a plenum space
It is 3x to 5x more expensive than PVC cable

15. Crossover Cable Connect two PCs without hub
1-3, 2-6, 3-1 and 6-2 or “A” on one end and “B” on the other
Be sure to mark these cables!
Note that only 4 wires are required

16. Hubs and Switches
In a star bus network, all devices connect to a central hub or switch (now that prices have come down). Max 1024 devices to a switch.
When a wire breaks, only that device looses the network connection – the rest of the network remains functional
Hubs act as repeaters, amplifying the signals – can use them to extend cable runs past 100 meters (~360 feet)
They need electrical power…or PoE
Hubs rebroadcast signal to all ports; switch tries to be selective

17. Duplex Full-duplex: can both send and receive at the same time
Half-duplex: either send or receive – like “push to talk” phones

18. Fiber Optic Ethernet
Uses light to transmit data therefore immune to noise and grounding issues
Up to 2000 meters cable length
Used for “backbone” runs
Half-duplex, so need two cables
Tends to be delicate, expensive and difficult to use – shows up in data centers and seldom on desktops
What is Verizon doing with Fios?

19. Fiber Terminations
Round ST
Square SC LC

20. Fiber Modes
LED-based light source uses Multimode cable – multiple light signals at the same time each using a different reflection angle
Good for short distances
Laser light-based use single-mode; high transfer rates over long distances but rare
Most fiber cable is multimode; delicate and expensive

21. Coax/BNC
Old form of networking – did not require hub/switch; still used in cable modems, TV and satellite connections
Type F connectors used in cable modems, etc. screw together
BNC connectors are quarter-turn
Can be RG-6 or RG-59 (thinner); 75-ohm impedance

22. Typical connection

23. Structured Cabling
The idea is to create a safe, reliable cabling infrastructure for all of the devices that need interconnection
Start with switches, cabling and PCs
Components of a network, such as how the cable runs through the walls and where it ends up
Connections leading outside your network
Standards from TIA/EIA

24. Structured Components
Telcom room – place where all wires lead to
Horizontal cabling – from telcom room to work area (run)
Work areas – where the PCs are

25. Horizontal Cabling Use solid core wire – better conductor but stiff
Away from the dreaded vacuum cleaners!
Idea is that it does not get moved around very much, if at all

26. Telco Room Equipment racks – from railroad days – 19” wide
Tall: 1.75” – called a U
Devices are 1U, 2U or 4U – mostly
Patch Panels allow wiring punchdown on back side and patch cables on the front side
Patch panels have CAT rating, so check it

27. RJ-45 Jack Crimping Take Network+ , Cisco or follow the book’s figures
EZ-RJ-45 jacks may be more expensive, but they are worth every penny

28. Work Area Wall plate to terminate horizontal run
Plates have CAT ratings too
Mike suggests looking here first if the user has lost connection to the network