Transcript Pat Lee`s Home PC Network

Case Study:
a tL
P
e e ’sHom
e P
C
e twork
N
Chapte r1 a
p
U d
a te d Ja nu
a ry 2007
Panko’s
Business Data Networks and Telecommunications, 6th edition
Copyright 2007 Prentice-Hall
May only be used by adopters of the book
Pat Lee’sHome Network
• Pat Lee is a vice president at FBP
• Wants a network in her home
–F
a mily’s m
a in com
p u
te r is th e downs
ta ir s P
C
–D
a ug
h te r Emilyh a sa P
C inh e rr oom
–a
W n
t s to conn
e ct bo
th to th e In
te rn
e t th roug
h a
r o
b
a db
a nd (h ig
h -sp e e d) ca ble mod
e me
s rvice
• Perspective
– A sm
a ll LAN bu
t h a sa ll th e e
k yn
e two
r ke le m
e n
t s
1a-2
Figure 1a-2: Coaxial Cable
Common
Axis
Inner
Outer
Conductor
Conductor
(wire)
Insulation (cylinder)
Insulation
Two conductors
are required
for
Two conductors
are required
for transmission
1a-3
Figure 1a-1: Pat Lee’sHome Network
1.
Coaxial Cable
to ISP
2.
Cable
Modem
3. UTP Cord
4.
Access
Router
1a-4
Figure 1a-1: Pat Lee’sHome Network, Continued
6.
A1-BD-33-6E-C7-BB
PC in Emily’s Room
4.
Access
Router
5. UTP
Cord
5. UTP
Cord
6.
B2-CD-13-5B-E4-65
PC in Study
1a-5
Figure 1a-5: Unshielded Twisted Pair (UTP) Cord
With RJ-45 Connector
4-Pair Unshielded Twisted Pair (UTP)
Industry Standard Pen
8-Pin RJ-45 Connector
UTP Cord
1a-6
Figure 1a-1: Pat Lee’sHome Network, Continued
6.
A1-BD-33-6E-C7-BB
PC in Emily’s Room
7. File
Sharing
6.
B2-CD-13-5B-E4-65
PC in Study
1a-7
Figure 1a-1: Pat Lee’sHome Network, Continued
6.
A1-BD-33-6E-C7-BB
PC in Emily’s Room
8. Printer
Sharing
6.
B2-CD-13-5B-E4-65
PC in Study
1a-8
F
i
g
u
r
e
1
a
-
7
:
H
About 4 inches (10 cm) Wide
Power
Jack for
External
Power
Switch Ports
UTP Cords
Run to Stations
WAN Port
UTP Cord
Runs to
Cable Modem
o
m
e
N
e
tw
o
r
k
A
c
Figure 1a-9: Ethernet Switch Operation
Switching Table
Port Host
10
A1-44-D5-1F-AA-4C
13
B2-CD-13-5B-E4-65
15
C3-2D-55-3B-A9-4F
16
D4-47-55-C4-B6-9F
Ethernet Switch
UTP
UTP
Frame To C3…
A1-44-D5-1F-AA-4C
UTP
UTP
D4-47-55-C4-B6-9F
Frame To C3…
C3-2D-55-3B-A9-4F
B2-CD-13-5B-E4-65
1a-12
Figure 1a-8: Logical Functions of the Access
Router
Cable
Modem
Access Router
Router Function
DHCP
Server
Function
NAT
Function
Switch Function
1a-13
Figure 1a-10: DynamicHost Configuration Protocol
(DHCP)
ISP
DHCP Server
Cable
Modem
1.
IP Address =
60.47.112.6
Access Router
A1-BD-33-6E-C7-BB
PC in Emily’s Room
The ISP only
Gives each home a
Single IP addressB2-CD-13-5B-E4-65
PC in Study
A DHCP Server
provides User PCs with
a temporary IP Address
each time the user
connects to the Internet
1a-14
Figure 1a-10: DynamicHost Configuration Protocol
(DHCP)
ISP
DHCP Server
A1-BD-33-6E-C7-BB
IP Address = 192.168.0.3
PC in Emily’s Room
1.
IP Address =
60.47.112.6
Internal
DHCP
Server
Access Router
2. IP Address =
192.168.0.3
2. IP Address =
192.168.0.2
The access router’s
internal DHCP server
gives private IP
Addresses to each PC
B2-CD-13-5B-E4-65
IP Address = 192.168.0.2
PC in Study
1a-15
Figure 1a-11: NetworkAddress Translation (NAT)
2. Packet from
60.47.112.6
Webserver
IP Address=
123.7.86.285
Cable
Modem
Internal
NAT
Module
Access Router
The access router’s NAT
module translates between the
private IP Addresses and
the single ISP-given IP Address
1. Packet from
192.168.0.2
PC in Study
192.168.0.2
1a-16
Figure 1a-11: NetworkAddress Translation (NAT),
Continued
3.
Packet
to
60.47.112.6
Webserver
IP Address=
123.7.86.285
Cable
Modem
Internal
NAT
Module
Access
Router
4. Packet to
192.168.0.2
PC in Study
192.168.0.2
1a-17
Perspective
• Pat Lee would like to serve the upstairs computer
wirelessly
• This requires a wireless access point connected to
the router or built into the router
• The upstairs computer must have a wireless NIC
• The downstairs computer, which is next to the
access router, will still be connected via UTP
• If a separate wireless access point is used, it must
be connected to the access router via UTP
1a-18
Figure 1a-12: Pat Lee’s Wireless LAN
Option with Separate Wireless Access Point
Wireless
Access Point
Access
Router
UTP Cord
A1-BD-33-6E-C7-BB
PC in Emily's Room
with Wireless NIC
Wireless
Communication
UTP Cord
B2-CD-13-5B-E4-65
PC in Study
New
Note: This option is rarely economical today
1a-19
Figure 1a-12: Pat Lee’s Wireless LAN
Option with Access Router with Integrated Wireless Access Point Functionality
A1-BD-33-6E-C7-BB
PC in Emily's Room
with Wireless NIC
Wireless
Communication
Access Router
with Built-in
Wireless Access Point
Functionality
1a-20
Figure 1a-13: Access Routerwith Wireless Access
Point and Wireless NICs
Access Router with
Wireless
Access Point
Internal
Wireless
NIC
Antenna
PC Card or
ExpressCard
Wireless NIC
Antenna
External Wireless
NIC with
USB Connector
1a-21
Configuration
Not in the
Book
• Each computer must be configured for
communication with the outside world. See Chapter
1b for details.
• Each computer must be configured for file and print
sharing. See Chapter 1b for details.
• The access router has a built-in webserver,
allowing either of the two PCs to configure it using
a browser.
1a-22
Figure 1a-14: Peer-to-Peer Service Versus
Dedicated Servers
• Peer-to-Peer Networks
– Clie n
t s se rving o
th e r clie n
t s
– In
e xp e nsiv
e —no n
e e d top u
r ch a se a d
e dica te d se rve r
–p
O e ra tion
a lp roble ms fo
r th
o e r us
e rs ifa use r C
P is
tu
r n
e d off o
r cra sh e s
– Poo
r e
s cu
r ti y: Nop a sswo
r do
r h
s a re dp a sswo
r d fo
r
sh a e
r d dire ct ro ie s
1a-23
Figure 1a-14: Peer-to-Peer Service Versus
Dedicated Servers
• Dedicated Servers
–e
S rve rs h
t a ta re no
t a lso use d simulta n
e ouslya s us
e r
C
P s
– Do no
t use ta
s nd
a rd clie n
t e
v rsions of Mic
r osoft
Windows (XP,a nd so fo
r th )
–h
T e y us
e p
s e cia l se rv
e rp
o e ra ting syste ms
• Known fo
r h is
t o
r ic
a lre a sonsa s n
e two
r ko
p e ra ting
syste ms (NOSs)
• On
e po
p ula r NOS is Mic
r osoft Windows (la te st
ve rsion is Windows S
e rv
e r 2003)
• Ano
th e r is Unix, w
h ic
h h a s ve rsions fo
r C
P s (Linux,
BSD,e tc.)
1a-24
Figure 1a-14: Peer-to-Peer Service Versus
Dedicated Servers
• Dedicated Servers
– NOSs fo
r d
e dica te d se rve rsa re r ic
h in funct ion
a lit y
•h
T e ya re e
d sign
e d to e
s rve a
m ny use rs with a
m ny
se rvice s
•H
a ve str ong se cu
r it y
– Unfo
r tun
a te ly, e
d dica te d se rv
e rsa re e
v rye xp e nsiv
e
– Insta lla tionre quire s sp e cia lize d tra ining
–M
a ke no se ns
e fo
r h om
e us
e
1a-25
Figure 1a-14: Peer-to-Peer Service Versus
Dedicated Servers
• Network Attached Storage (NAS) Units
– Boxe s th a t cos
t $200 to $500
– Con
ta ina a
l rg
e sh a re dh a rd d
r iv
e
– RJ-45p lugsa llow th e NAS to b
e conn
e cte d to th e swit ch
in th e a cce ssr ou
te r via UTP
– No mouse o
r e
k ybo
a rd;h a sa built -in w
e bs
e rve r h
t at a
c n
b
e a
m n
a g
e de
r mo
te ly bya clie n
t C
P
– Do no
t los
e a va ila bilit y w
h e na use r C
P is tu
r n
e d off o
r
cra sh e s
–e
B tte r e
s cu
r it y th a n P
C file e
s rvice
–a
B cku
p is cr ucia l
1a-26