wan and remote access technologies chapter 7. topics wan technologies: internet access technologies...

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/demodulatorConverts analog signal into digital dataCompatible 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 AddressI/O Address

IRQIRQ

IRQ, DMA and I/O Addresses

IRQ Assignments0 = System Timer1 = Keyboard2 = Cascade to IRQ 93 = COM 2 & 44 = COM 1 & 35 = LPT 26 = Floppy-Drive Controller7 = LPT 18 = Real Time Clock9 = Cascade from IRQ 210 = Available11 = Available12 = PS/2 Mouse13 = Math Coprocessor14 = Primary Hard-Drive Controller15 = Secondary Controller

DMA Assignments0 = free1 = free2 = Floppy Drive3 = LPT 14 = Secondary DMA Controller5 = free6 = free7 = free

I/O Memory AddressesCOM 1 = 3F8hCOM 2 = 2F8hCOM 3 = 3E8hCOM 4 = 2E8hLPT 1 = 378hLPT 2 = 278hPrimary IDE = 1F0hSecondary IDE = 170hFloppy Drive = 3F0hNetwork 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 mechanismEstablished connection mechanism Network resourcesNetwork resources

PSTNPSTN

PSTNor

PTOS

PSTNor

PTOS

Modem ModemRemote computer Remote

access server

Remote Networking

Supports mobile or distant usersControls amount of network that is availableProvides network services

EmailFile and print servicesDatabase services

Remote Access Networking

Server provides security All traffic from remote node passes through server

Remote access server

PSTNor

POTS

PSTNor

POTS

Modem ModemRemote node

Remote Control Networking

Host clientRemote client

Host client should be a dedicated machine

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

betweenthe user and the

Telco.• Local Loop: Region between the

COand the Demarc.

Leased Data Lines

Telco network

Leased data linesLeased data lines

ISDN

ISDN adapter ISDN switch

Subscriber Telco

Packetdata network

Switcheddata network

Privateline 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 loopphone lineLocal loopphone line Voice

Digital

DSL Hardware

Local

loop

VoiceDSL

splitterDSL

splitter

SDP110

Professional Workstation 5000

SDP110

Professional Workstation 5000

DSL Modem

Customer premises

Telco

PSTN

DSLAM Digital

DSL

SDP110

Professional Workstation 5000

SDP110

Professional Workstation 5000 Data

Voice

DSL networkSplitter Splitter

Cable Internet Access

Cable TV feedCable TV feed

TV signalTV signal

Cable modem

ISP

Frame Relay

Frame Relay Bearer Services

(FRBS)

Frame Relay Bearer Services

(FRBS)

DCEDCE

Customer network

DTE

Customer network

DTEClean carrier networks

Less error checking requiredClean carrier networks

Less error checking required

CSU/DSU

Frame Relay Access Device (FRAD)

ESES

ESES ESES

ESES

Another Frame Relay

• Uses:– PVC Permanent– SVC Switched

• CIR:– Committed

Information Rate

• Up to 1.544Mbps

Virtual Circuits

Logicalconnections

Logicalconnections

Permanent virtual circuits: Provider network always onPermanent virtual circuits: Provider network always on

Switched virtual circuits: Provider network connects when needed

Switched virtual circuits: Provider network connects when needed

PVCs

DLCI=40 40 to 16CIR=56 Kbps

Telco network is always on.

DLCI=60

60 to 18CIR=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 circuitT-Carrier circuit

T1: 24 channels

T3: 672 channels

T-Carrier System

Line Channels Speed per Channel Data Rate DS Specification

T1 24 64.4 Kbps 1.544 Mbps DS-1

T2 96 64.4 Kbps 6.312 Mbps DS-2

T3 672 64.4 Kbps 44.736 Mbps DS-3

T4 4032 64.4.Kbps 274.176Mbps DS-4

T5 5760 64.4Kbps 400.352Mbps DS-5

• Fractional T uses only part of a T service

ATM

Fast 155 Mbps to 622 MbpsSupport data, voice, and video53-byte cellBuilt in quality of servicePVC or SVC

ATM

EndpointsEndpoints

Data

Voice

Video

Public ATM networkPrivate ATM LAN

ATM switch

ATM Data

ATM Frame

Header Payload5 bytes 48 bytes

53 bytes

ATM Virtual Paths

1234

Transmission

Path A5678

VP1VP1

VP2VP2

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 NETworkExcellent bandwidth managementBuilt-in fault recoveryHigh bandwidth = 51.84 Mbps to 70 GbpsOften used as a backbone for frame relay and ATM

SONET Network Components

Broadband backbone network

Regional networkIntegrated management

Collector ring

LAN

Routes between regional networksRoutes between

regional networks

Joins multiplecollector ringsJoins multiplecollector rings

DCS to place customer’s signal on ring

DCS to place customer’s signal on ring

SONET Collector Ring

LAN LAN

DCS DCS

ATM T-1

OC-3

SONET Regional Ring

ADM ADM

ADM ADM

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 dataOne ring carries data

One ring carries control signals

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

Carrier protocol (IP) moves the data

ISP

Passenger protocol enters the network

Passenger protocol enters the network

Passenger protocol leaves the network

Passenger protocol leaves the network

IP data unencapsulated

IP data unencapsulated

IP data encapsulated

IP data encapsulated

Tunnel Types

ISPS D

Com3 AccessBuilder

Remote Office 600

POWE R

LAN

WA N

ISDN

ALERT

HOME

ENTER

S D

Com3 AccessBuilder

Remote Office 600

POWE R

LAN

WA N

ISDN

ALERT

HOME

ENTER

S D

Com3 AccessBuilder

Remote Office 600

POWE R

LAN

WA N

ISDN

ALERT

HOME

ENTER

S D

Com3 AccessBuilder

Remote Office 600

POWE R

LAN

WA N

ISDN

ALERT

HOME

ENTER

Voluntary tunnel from end to end

ISPS D

Com3 AccessBuilder

Remote Office 600

POWE R

LAN

WA N

ISDN

ALERT

HOME

ENTER

S D

Com3 AccessBuilder

Remote Office 600

POWE R

LAN

WA N

ISDN

ALERT

HOME

ENTER

S D

Com3 AccessBuilder

Remote Office 600

POWE R

LAN

WA N

ISDN

ALERT

HOME

ENTER

S D

Com3 AccessBuilder

Remote Office 600

POWE R

LAN

WA N

ISDN

ALERT

HOME

ENTER

Compulsory tunnel between routers through public network

SDP110

Professional Workstation 5000

SDP110

Professional Workstation 5000

SDP110

Professional Workstation 5000

SDP110

Professional Workstation 5000

SDP110

Professional Workstation 5000

SDP110

Professional Workstation 5000

SDP110

Professional Workstation 5000

SDP110

Professional Workstation 5000

VPN in Windows 2003

Home209.89.29.40

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