Networking Technologies
Topologies
Lesson 3
( LO 1.2)
Lecturer: Daniel K. Tom-Joe
1
Topology: Scope of Networks
Local Area
Network
Wide Area Network
2
Bus Topology
Segment
Terminator
Terminator
3
Star Topology
Hub
4
Ring Topology
5
Mesh Topology
6
Hybrid Topologies
Star-Bus
Bus
Star-Ring
7
Ethernet
Transmits signal
Detects signal
Carrier Sense Multiple Access
Characteristics
Collision detected
Collision Detection
Description
Access Method
CSMA/CD
Transfer Speed
Standard Ethernet – 10 Mbps
Fast Ethernet – 100 Mbps
Gigabit Ethernet – 1 Gbps (1000 Mbps)
8
Fiber Distributed Data Interface
Secondary Ring
Primary Ring
Characteristics
Description
Access Method
Token passing
Transfer Speed
Fiber-optic at 155 Mbps to 622 Mbps
9
Token Ring
Physical
Ring
MSAU
Characteristics
Logical
Ring
Description
Access Method
Token passing
Transfer Speed
4 to 16 Mbps for all cable types
A multistation access unit (MSAU) is a network hub
in Token Ring local area networks (LANs).
10
Network Cables
Types of Cables
Twisted-Pair
10BaseT
Unshielded (UTP)
Shielded (STP)
Coaxial
10Base2, 10Base5
ThinNet
ThickNet
Fiber-Optics
11
Wireless Communication
DevicesWireless Communication Devices
Infrared Transmission
Narrowband Radio Transmission
12
Gateways
Ethernet
Gateway
Token Ring
13
Infrared Data Association (IrDA)
Wireless Communication by Using IrDA
Windows
Client
Laptop
Mouse
14
Types of Data Transmissions
Unicast
Broadcast
Multicast
15
IP Address Classes
Class A
Class B
Network ID
Host ID
Network ID
Host ID
Network ID
Class C
w
x
Host ID
y
z
16
IP Addresses
192.168.2.100
IP
Address
192.168.3.100
192.168.1.100
192.168.1.0
192.168.2.0
192.168.3.0
Network ID
192.168.1.100
192.168.2.101
Host ID
17
Subnets
Subnet 1
Subnet 2
1
Hub
2
Router
Hub
18
Addressing Guidelines
The First Number in the Network ID Cannot Be 127
The Host ID Cannot Be All 255s
The Host ID Cannot Be All Zeros ( 00000.
The Host ID Must Be Unique to the Local Network ID
19
CIDR Notation
IP
Address
Subnet
Mask
10 .
.
7
00001010 11011001 01111011 00000111
255 . 255 . 240
. 0
11111111 11111111 11110000 00000000
Number of Subnet
Mask Bits (ones)
IP Address in
CIDR Notation
217 . 123
8 + 8 + 4 + 0 = 20
10.217.123.7/20
20
The Internet
Server
Internet
Text, Audio, Video,
and Graphics Data
Connection Using
TCP/IP Protocol
Client
21
Internet Services
 Electronic
Mail (e-mail)
 World Wide Web (WWW)
 Chat
 Internet News
 File Transfer Protocol (FTP)
 Telnet
Internet
22
Intranets
Intranet
Internet
Extranet
23
Uniform Resource Locator (URL)
 URL
(http://example.microsoft.com/tutorial/
default.html)
– Protocol used (http://)
– DNS address (example.microsoft.com)
– Path on the server (/tutorial/default.html)
http://example.microsoft.com/tutorial/default.html
24
Domain Naming

Domain Name (example.microsoft.com)
– Top-level domain (com)
– Second-level domain (microsoft.com)
– Subdomain (example.microsoft.com)
com
microsoft.com
example.microsoft.com
25
Domain Organization
Forest
Domain
Domain
nwtraders.msft
Tree
Domain
Domain
Tree
Domain
namerica.nwtraders.msft
Domain
samerica.nwtraders.msft
26
Features of a Domain
Single Logon
Single User Account
Centralized Management
Scalability
27
Benefits of a Domain
Organized
Objects
Easy Location of
Information
Paris
Sales
Repair
User1 Computer1 User2
Streamlined Access
Printer1
Delegated Authority
28
Internet Protocols
 HTTP
Server
 HTTPS
Internet
 FTP
 SMTP
Data
 NNTP
Connection Using an
Internet Protocol
 HTML
 DHTML
Client
29
TCP/IP Layers
IP
Application Layer
HTTP
FTP
Application
Layer
Transport Layer
TCP
UDP
Transport Layer
Internet IGMP
Layer
ICMP
ARP
Network
Layer
ATM Interface
Ethernet
Internet Layer
Network
Interface Layer
30
Network Address Translators (NATs)
192.168.0.10
Web Server
w2.x2.y2.z2
Web Browser
w1.x1.y1.z1
Internet
NAT
31
CAT5 wiring for networks
– What is unshielded twisted pair, aka UTP, cabling?
– What are the twists for?
32
Categories of UTP

Category 3 – Telephone Cable or 10
Mbps data
Category 5 – 10/100 Mbps
 Category 5e – 10/100 Mbps or 1000 Mbps (1 Gbps) for
short distances
 Category 6 & 7 – 10/100/1000 Mbps

33
Types of cables
– Straight through

Used to connect computers to switches or routers to
switches
– Crossover/cross connect

used to connect a computer to another computer or a
switch to another switch
– Roll/rollover cables

Used to connect to a console port on managed
switches or routers
34
Tools & Materials for Making Patch
Cables

Crimp Tool

Cable Stripper (Cyclops)

Cat 5 or 5e UTP cable

RJ-45 – Cat-5e modular plugs

Cable tester
35
What kinds of things can go wrong
when making a a cable?
Not all wires made a connection
 Wires were in the wrong order
 Too much of the cabling jacket was cut off
 Wires were untwisted too much, causing
interference between wires.

36
What kinds of things can go wrong
when making a a cable?

Construction problems
37
What kinds of things can go wrong
when making a a cable?

Wiring order is mixed up or open
 Crossed Pairs – The twisted wires are still paired,
but you mixed up the correct order of the wire
pairs.
 Reversed Pair – The reversed-pair fault occurs
when a wire pair is correctly installed on one
connector, but reversed on the other connector.
This is also called a polarity reversal or tip-andring reversal.
 Split Pairs – A split-pair wiring fault occurs when
one wire from one pair is switched with one wire
from a different pair at both ends. This mixing
hampers the cross-cancellation process and makes
the cable more susceptible to crosstalk and
interference.
 Open Pair – Lack of continuity between pins at
both ends of the cable on one or more wires.
There is no path to carry electrical signals.
38
Wiring Order for Cat5 Cable
Crimps

Pin outs - Why do we need standards?
– No matter what wiring order you use, a cable will work as long as the
other end is wired in the same order. Many networking professionals,
particularly those who were self taught, had their own wiring orders they
used.
– However, wiring pairs may not be kept together. This is bad because
twisted pair cabling use the twists in the wires to control noise. This is a
simplified way of thinking of how it works. Both wires receive the same
noise; what is received on the reference is subtracted from the other. This
can dramatically affect performance
– Sometimes, you work on one end, but you were not the one who wired the
other end. You expect it to be wired a certain way. The order means
something.
– The standard was published in 1991 to create a multiproduct, multivendor,
standard for connectivity. Prior to the adoption of this standard, many
"proprietary" cabling systems existed. This was very bad for the
consumer. Two main standards for UTP – 568A and 568B


568A is most commonly used by the telecommunications industry
568B is most commonly used in data networks
39
Patch Cable Assembly Instructions
1. Skin off the cable jacket approximately 1" or
slightly more.
2. Un-twist each pair, and straighten each wire
between the fingers.
3. Place the wires in the order of one of the two
diagrams shown above (568A or 568B). Bring
all of the wires together, until they touch.
4. At this point, recheck the wiring sequence
with the diagram.
http://www.lanshack.com/make-cat5E.aspx
40
Making patch cables
Patch Cable Assembly Instructions
5. Optional: Make a mark on the wires at 1/2" from the
end of the cable jacket.
6. Hold the grouped (and sorted) wires together tightly,
between the thumb, and the forefinger.
7. Cut all of the wires at a perfect 90 degree angle from the
cable at 1/2" from the end of the cable jacket. This is a
very critical step. If the wires are not cut straight, they
may not all make contact. We suggest using a pair of
scissors for this purpose.
7B. Conductors should be at a straight 90 degree angle,
and be 1/2" long, prior to insertion into the connector.
8. Insert the wires into the connector (pins facing up).
41
Patch Cable Assembly Instructions (cont.)
9. Push moderately hard to assure that all of the
wires have reached the end of the connector. Be
sure that the cable jacket goes into the back of the
connector by about 3/16".
9. Place the connector into a crimp tool, and
squeeze hard so that the handle reaches it's full
swing.
10. Repeat the process on the other end. For a
straight through cable, use the same wiring. For a
"crossover" cable, wire one end 568A, and the
other end 568B.
11. Use a cable tester to test for proper continuity.
42
Wire Order for Types of cables
– Straight through


Used to connect computers to switches
or routers to switches
568B on one end to 568B on the
other



568A on one end to 568A on the other
Crossover/cross connect
used to connect a computer to another
computer or a switch to another switch
568B on one end to 568A on the other
43
Making UTP connections
Notes Regarding Making Category 5 Patch Cable
1) The RJ-45 plugs are normally made for either solid conductors or stranded
conductors. Using the wrong type can possibly cause intermittent problems.
2) Ordinarily, it would be taboo to untwist the pairs of any category 5 cable. The
one exception to this rule is when crimping on RJ-45 plugs. It would be
impossible to insert the wires into the channels without first untwisting and
straightening them. Be sure not to extend the un-twisting, past the skin point. If
you do it properly, you will wind up with no more than 1/2" of untwisted
conductors (up to 1/2" of untwist meets the cat 5 specification).
3) If the completed assembly does not pass continuity, you may have a problem
in one, or both ends. A good cable tester may tell you which end is faulty.







First try giving each end another crimp.
If that does not work, then carefully examine each end.
Are the wires in the proper order?
Do all of the wires fully extend to the end of the connector?
Are all of the pins pushed down fully?
Cut off the suspected bad connector, and re-terminate it.
If you still have a problem, then repeat the process, this time giving more scrutiny to
the end that was not replaced.
44
Mixing Data and Telephone on cat5
45
Can I run a LAN and telephones
on the same LAN cable?




The technical answer is … it depends. If you are using
10BaseT or 100Base-TX, it may work. However you are
taking a RISK of damaging equipment in certain types of
installations.
If you do wire your network this way, you may have to re-wire
later to prevent problems.
Increasingly we are seeing 'Power-over-Ethernet (PoE)'
systems which can make use of both spare pairs in 1000baseTX wiring and will likely provide power for VoIP or other
technologies. If you mix PoE systems with non-standard
wiring you could destroy or damage equipment and have
other unpleasant or harmful effects.
1000base-T (gigabit Ethernet) uses all 4 pairs (8
conductors) and cannot be used with mixed LAN and
telephony wiring.
46
Punching down UTP connections in
Patch Panels

What is a patch panel?
– Below you can see a patch panel for data networks.
47
Punching down UTP
connections in Patch Panels

What is a patch panel?
– RJ-45 on one side, 110 punch down block on the other side
• What is a punching down block?
– connecting communications conductors is at a multi-terminal
assembly of self-stripping, crimp connections
• 66 vs. 110 blocks
• 66 blocks are for voice conductors
• 110 blocks are for data conductors.
• We use patch panels and punch-down blocks to facilitate testing
and provide for additions and modifications to the cable plant
(cabling system).
• The outlet itself is almost always one or two RJ-45 jacks you
mount on a single-gang plate. (The RJ-45 is the 8-pin modular
phone plug. Universally, we use it for data networks.)
48
What is punching down for?
It's important to leave enough extra cable at each
outlet point. The recommended lengths are a
minimum of 10 feet in the telecommunications
closet for both twisted-pair, and 12 inches for
twisted-pair cable at the outlet.
 Don’t stretch the cable too tight
 Leave a small loop of cable for alterations
 Do not nick the wire when stripping

49
Tools for Punching Down
110 Punch down tool
 110 blade
 Patch panel or jack
 Cable Stripper
 Cable
 Wire cutter
 Cable Tester

50
Punching Down Cat5 on a 110 Block
51
Let’s Punch down on a 110
block!

Step 1. Carefully strip the jacketing from the
cable. Do not remove any insulation from the
conductors.
52
Let’s Punch down on a 110 block!
53
Let’s Punch down on a 110 block!

Step 3:
Trim off any excess wire (if 110 tool does not
cut).
54
Let’s Punch down on a 110 block!

Step 4:
Complete the installation by securing cables to
panel using wire ties.
55
Cat5E Installation Do's and Don’ts
– Do Keep all cable runs to a maximum of 295 feet (for each run).
– Do Maintain the twists of the pairs all the way to the point of
termination, or no more than 0.5" (one half inch) untwisted
– Do Not Skin off more than 1" of jacket when terminating
– Do Make gradual bends of the cable, where necessary. No
sharper than a 1" radius. (about the roundness of a half-dollar)
– Do Not Allow the cable to be sharply bent, or kinked, at any
time. This can cause permanent damage to the cables' interior.
– Do Dress the cables neatly with cable ties. Use low to moderate
pressure.
– Do Not Over tighten cable ties. We recommend Hook and Loop
(Velcro) Cable Ties for commercial installations.
– Do Cross-connect cables (where necessary), using cat 5E rated
punch blocks and components.
– Do Not Splice or bridge category-5E cable at any point. There
should never be multiple appearances of category 5E cable.
– Do Use low to moderate force when pulling cable.
56
Cat5E Installation Do's and Don’ts
– Do Not Use excessive force when pulling cable.
– Do Use cable pulling lubricant for cable runs that may otherwise require great
force to install. (You will be amazed at what a difference the cable lubricant
will make)
– Do Not Use oil, or any other lubricant, not specifically designed for cable
pulling. Oil, or other lubricants, can infiltrate the cable, causing damage to the
insulation.
– Do Keep cat 5E cables as far away from potential sources of EMI (electrical
cables, transformers, light fixtures, etc.) as possible.
– Do Not Tie cables to electrical conduits, or lay cables on electrical fixtures.
– Do Install proper cable supports, spaced no more than 5 feet apart.
– Do Not Install cable that is supported by the ceiling tiles (this is unsafe, and is
a violation of the building codes).
– Do Always label every termination point. Use a unique number for each cable
segment. The idea here, is to make moves, adds, changes, and troubleshooting
as simple as possible.
– Do Always test every installed segment with a cable tester. "Toning" alone, is
not an acceptable test.
– Do Always install jacks in such a way as to prevent dust and other
contaminants from settling on the contacts. The contacts (pins) of the jack
should face up on flush mounted plates, or left, right, or down (never up) on
57
Cat5E Installation Do's and Don’ts
– Do Always leave extra slack on the cables, neatly coiled up in the ceiling or
nearest concealed place. It is recommended that you leave at least 5 feet at the
work outlet side, and 10 feet at the patch panel (wiring hub) side.
– Do Not Ever install cables "taught" in the ceiling, or elsewhere. A good
installation should have the cables loose, but never sagging.
– Do Always use grommets to protect the cable where passing through metal
studs or anything that can possibly cause damage to them.
– Do Choose either 568A or 568B wiring standard, before you begin your
project. Wire all jacks and patch panels for the same wiring scheme (A or B).
– Do Not Mix 568A and 568B wiring on the same installation.
– Do Not (1 exception) Use staples on category-5E cable that crimp the cable
tightly. The common T-18 and T-25 cable staples are not recommended for
category 5E cable. The T-59 insulated staple gun is ideal for fastening cat5 & 6
and fiber optic cabling as it does not put any excess pressure on the cable.
– Do Always obey all local, and national, fire and building codes. Be sure to
"firestop" all cables that penetrate a firewall. Use plenum rated cable where it is
mandated.
58
Punching down Cat5 on a 110 block

Think you have it? Try this quiz to check your
mastery.
– http://www.jimhayes.com/VHO/utpterm/quiz.htm
59
End of Today's Lecture
Any Questions?
60