WAN and Remote
Access Technologies
Chapter 7
Topics
•
WAN Technologies:
•
Internet Access Technologies
•
Remote Access Protocols and services
•
Connections to servers
Remote Access Connection Configuration
Requirements
•
Two basic components:
–
A
remote computer and
–
A
remote access system on the network
Hardware Requirements
•
Modem
•
Configuring an Internal Modem
–
Understand IRQ,
I/O, and COM ports
Modems
Modulator/demodulator
Converts analog signal into digital data
Compatible with telephone system
V Dot Standards
ITU
Standard
Speed
V.32
9,600 bps synchronous; 4,800 bps asynchronous
V.32 bis
14.4 Kbps synchronous and asynchronous
V.34
28.8 Kbps
V.34 bis
33.6 Kbps
V.42
57.6 Kbps; specifies standards for error checking
V.42 bis
57.6 Kbps; specifies standards for compression
V.90
56 Kbps upstream; 33.6 Kbps downstream because
downstream data is modulated
Know
your available resources
•
Open Com ports
•
Open DMA channels
•
The UART type
•
Software Requirements
Resource Settings for COM1
I/O Address
IRQ
IRQ
, DMA and I/O Addresses
IRQ Assignments
0
=
System Timer
1
=
Keyboard
2
=
Cascade to IRQ 9
3
=
COM 2 & 4
4
=
COM 1 & 3
5
=
LPT 2
6
=
Floppy
-
Drive Controller
7
=
LPT 1
8
=
Real Time Clock
9
=
Cascade from IRQ 2
10
=
Available
11
=
Available
12
=
PS/2 Mouse
13
=
Math Coprocessor
14
=
Primary Hard
-
Drive Controller
15
=
Secondary Controller
DMA Assignments
0
=
free
1
=
free
2
=
Floppy Drive
3
=
LPT 1
4
=
Secondary DMA Controller
5
=
free
6
=
free
7
=
free
I/O Memory Addresses
COM 1
=
3F8h
COM 2
=
2F8h
COM 3
=
3E8h
COM 4
=
2E8h
LPT 1
=
378h
LPT 2
=
278h
Primary IDE
=
1F0h
Secondary IDE
=
170h
Floppy Drive
=
3F0h
Network Adapter
=
300
-
310
NetTech Solutions
POTS
•
POTS has many advantages,
including:
–
It is inexpensive to set up. Almost every
home in the United
States and Canada
has or can have a telephone
connection.
–
There are no LAN cabling costs.
–
Connections are available in many
countries throughout the world.
Remote Networking
Established connection mechanism
Network resources
PSTN
PSTN
o
r
PTOS
Modem
Modem
Remote
computer
Remote
access server
Remote Networking
Supports mobile or distant users
Controls amount of network that is
available
Provides network services
Email
File and print services
Database services
Remote Access Networking
Server provides security
All traffic from remote node passes through server
Remote
access server
PSTN
or
POTS
Modem
Modem
Remote
node
Remote Control Networking
Host client
Remote client
Host client should be a
dedicated machine
RAS Servers
•
Windows servers
–
Routing and Remote Access Services
(RRAS)
–
Available for Windows NT 4.0, Windows
2000 Server, Windows XP Professional,
and Windows Server 2003
–
Can use existing user accounts
•
Third
-
party servers
–
Perle
–
Citrix
–
Patton
–
Need to synchronize user accounts
Network Protocols
•
Transmission Control
Protocol/Internet Protocol (TCP/IP)
•
Internet Packet
eXchange
(IPX)
•
Point
-
to
-
Point Protocol (PPP)
•
Point
-
to
-
Point
Tunneling
Protocol
(PPTP)
•
Layer 2
Tunneling
Protocol (L2TP)
Public and Switched
•
Public:
for a fee, anyone can lease
the use of the network, without the
need to run cabling.
•
Switched
explains how the phone
system works.
Terms:
•
CO:
Central Office.
•
Demarc
:
Point
of control between
the user and the Telco.
•
Local Loop:
Region between the CO
and the
Demarc
.
Leased Data Lines
Telco network
Leased data lines
ISDN
ISDN adapter
ISDN switch
Subscriber
Telco
Packet
data network
Switched
data network
Private
line network
TA
NTU
•
Terminal Adapter
•
Network Termination Unit
ISDN Channels
B
B channel = Data
D channel = Change and control
BRI =
B
D
64K
64K
16K
23
B
ch
.
PRI =
D
64Kx23
64K
•
BRI has two B channels and one D channel.
•
Maximized throughput of 128Kbps
DSL
DSL modem
PSTN
Multiplexer
Customer
Telco
Local loop
phone line
Voice
Digital
DSL Hardware
Local
loop
Voice
DSL
splitter
DSL Modem
Customer
premises
Telco
PSTN
DSLAM
Digital
DSL
Data
Voice
DSL
network
Splitter
Cable Internet Access
Cable TV feed
TV signal
Cable modem
ISP
Frame Relay
Frame Relay
Bearer Services
(FRBS)
DCE
Customer
network
DTE
Clean carrier networks
Less error checking required
CSU/DSU
Frame Relay Access
Device (FRAD)
ES
ES
ES
ES
Another Frame Relay
•
Uses:
–
PVC Permanent
–
SVC Switched
•
CIR:
–
Committed
Information Rate
•
Up to 1.544Mbps
Virtual Circuits
Logical
connections
Permanent virtual circuits:
Provider network always on
Switched virtual circuits: Provider
network connects when needed
PVCs
DLCI=40
40 to 16
CIR=56 Kbps
Telco network is
always on.
DLCI=60
60 to 18
CIR=1.54 Mbps
DLCI=16
DLCI=20
DLCI=18
network1
network2
network3
network4
network5
SVCs
Telco network is normally off;
connections are switched on
when needed.
network1
network2
network3
network4
network5
The T
-
Carrier System
T
-
Carrier circuit
T1: 24 channels
T3: 672 channels
T
-
Carrier System
•
Fractional T uses only part of a T service
ATM
Fast 155 Mbps to 622 Mbps
Support data, voice, and video
53
-
byte cell
Built in quality of service
PVC or SVC
ATM
Endpoints
Data
Voice
Video
Public ATM network
Private ATM LAN
ATM switch
ATM Data
ATM Frame
Header
Payload
5 bytes
48 bytes
53 bytes
ATM Virtual Paths
1
2
3
4
Transmission
Path A
5
6
7
8
VP1
VP2
VC
SONET
•
Synchronous data transport
over fiber optic cable
•
Excellent bandwidth
•
Built
-
in fault recovery
•
Speeds up to 2.48
Gbps
•
OC and STS specifications
•
Self
-
healing dual
-
fiber ring
Optical Carrier (OC) System
OC
Specification
Number of
Channels
Data Rate
OC 1
810
51.84 Mbps
OC 3
2,430
155.52 Mbps
OC 9
7,290
466.56 Mbps
OC 12
9,720
622.08 Mbps
OC 18
14,580
933.12 Mbps
OC 24
19,440
1.244 Mbps
OC 36
26,160
1.866 Mbps
OC 48
2.488Gbps
OC 192
155,520
9.95 Mbps
SONET
Synchronous Optical
NETwork
Excellent bandwidth management
Built
-
in fault recovery
High bandwidth = 51.84 Mbps to 70
Gbps
Often used as a backbone for frame relay
and ATM
SONET Network Components
Broadband backbone network
Regional network
Integrated management
Collector ring
LAN
Routes between
regional networks
Joins multiple
collector rings
DCS to place customer’s
signal on ring
SONET Collector Ring
LAN
LAN
ATM
T
-
1
OC
-
3
SONET Regional Ring
Collector ring
Collector ring
OC
-
12
OC
-
3
OC
-
3
Pass through data
Drop
data
Add
data
Add/Drop
Mux
Fiber Distributed Data
Interface (
FDDI)
One ring carries data
One ring carries
control signals
FDDI Connectivity
DAS
SAS
•
Nodes are connected to the FDDI network
in one of two ways:
–
Dual attached stations (DAS)
–
Single attached station (SAS)
FDDI Failure Recovery
Auto
-
reconfiguration
Isolation
Remote Access Protocols
•
A remote access protocol manages the
connection between a remote computer
and a remote access server.
•
They include:
–
Serial Line Internet Protocol (SLIP)
–
Point
-
to
-
Point Protocol (PPP) and Point
-
to
-
Point Protocol over Ethernet (
PPPoE
)
–
Point
-
to
-
Point
Tunneling
Protocol (PPTP)
–
Layer 2
Tunneling
Protocol (L2TP)
–
Remote Access Services (RAS)
–
Remote Desktop Protocol (RDP)
Serial Line Internet Protocol (SLIP)
•
In 1984, students at the University of
California, Berkeley, developed SLIP
for UNIX as a way to transmit
TCP/IP over serial connections
(such as modem connections over
POTS).
•
SLIP does not support encrypted
passwords and therefore transmits
passwords in clear text, which is not
secure at all.
PPP
•
PPP is used to implement TCP/IP; it
is the protocol that establishes a
connection over point
-
to
-
point links
(for example, dial
-
up and dedicated
leased lines).
•
PPP uses the Link Control Protocol
(LCP) to communicate between PPP
client and host.
•
PPP uses LCP between client and
Host.
Configure
PPP in Vista
226
-
1234
Richard
************
RMFRED
PPPoE
•
This allows the authentication
methods of PPP to be used over
Ethernet and high
-
speed Internet
connections so individual users can
be authenticated for Internet access
over a shared medium like Ethernet
or DSL.
Point
-
to
-
Point
Tunneling
Protocol (PPTP)
•
PPTP is the Microsoft
-
created
protocol based on PPP.
•
It is used to create virtual
connections across the Internet using
TCP/IP and PPP so that two
networks can use the Internet as
their WAN link and yet retain private
network security.
•
PPTP is both simple and secure.
Configure
PPTP in Vista
209.89.29.40
Richard
***********
RMFRED
Layer 2
Tunneling
Protocol (L2TP)
•
Published in 1999 as proposed
standard
RFC 2661
, L2TP has its
origins primarily in two older
tunneling
protocols for PPP: Cisco's
Layer 2 Forwarding (L2F) and
Microsoft's
Point
-
to
-
Point
Tunneling
Protocol
(PPTP).
Tunneling
Carrier protocol (IP)
moves the data
ISP
Passenger protocol
enters the network
Passenger protocol
leaves the network
IP data
unencapsulated
IP data
encapsulated
Tunnel Types
ISP
Voluntary tunnel from end to end
ISP
Compulsory tunnel between routers
through public network
VPN in Windows 2003
Home
209.89.29.40
Remote Access Services (RAS)
•
RAS is used in smaller NT 4.0
networks where a dedicated dial
-
up
router is not practical or possible.
•
Windows 2000, however, comes with
the ability to share outbound
connections. This is set up with
Windows 2000’s RRAS utility.
Remote Desktop Protocol (RDP)
•
The Remote Desktop Protocol (RDP)
is very similar to the Independent
Computing Architecture (ICA)
protocol used by Citrix products.
•
It requires port 3389 to be open.
•
You can start RDP from the RUN line
using the
MSTSC
command.
Summary
•
Summary and
•
Exam
Essentials on page 309
•
Review Questions on page 310
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