VPNs & Specialized Network Services

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VPNs & Specialized Network Services

• Virtual private networks– Lowering the cost of enterprise links & enabling

remote access

• Frame relay as a replacement for private lines• T-1/E-1 the first high speed service; • ISDN - caller ID & video conferencing• Gigabit Ethernet in carrier & enterprise

metropolitan networks

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VPNs & Specialized Network Services continued

• ATM compared to IP

• SONET– In the backbone– In the metropolitan area– Compared to gigabit ethernet

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virtual private networks

Virtual: from the Latin excellence;Essence though not in fact actual

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IPSec virtual private network for remote access

•What are the advantages of VPNs?•Why are they important?•How can they be made secure?

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Key Components of Frame relay

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Multipoint private lines with hub and spoke for small locations

•Why use private lines rather than a virtual private network?

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Mesh network topology pros & cons

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Any-to-any mesh design in a VPN; hub and spoke (star) to headquarters forInternet access.

Mesh; hub & spoke combo

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Local and interexchange channels of a private line

•Billing, repair & installation ramifications

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Integrated access device for T-1s carrying voice and data

•Small & medium companies•Implication of competition

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T-1 and E-1

• 1.544 or 2.048 Megabits per second– Bell Standard– IT Standard

• Applications

T-1 Mux T-1 Mux

24 or 30 channels 24 or 30 channels

Fiber, copper or wireless media

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28 T-1s = a T-3 Circuit

ISP

Internet

London

Dallas

T-3T-1

T-1

Boston

Fiber or Wireless

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Videoconferencing using three bonded BRI ISDN circuits

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BRI ISDN bonding

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• PRI ISDN carrying the caller’s billed telephone number automatic number identification (ANI). The ANI is often the same as the customer’s telephone number.

Primary rate interface ISDN

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DSLAMs in digital loop carriers (remote terminals)

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Digital subscriber line service

• No need for fiber to the home or business

• A response to cable providers

• Use of same copper already deployed

• Strategic implications of RBOC & cable offerings

downstream

voice

data

upstream

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DSLAM connection to an Internet service provider

19Figure 5.14Neighborhood mini remote access multiplexers (MiniRAMs).

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Gigabit Ethernet

fiber-optic cabling and metropolitan fiber rings

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Leasing wavelengths in the metropolitan area

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Parallel streams in an ATM circuit

•Fixed size cells•Quality of service•Asynchronous switching•In the frame relay backbone

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- bidirectional duplicate rings in a carrier’s backbone network- The fiber glut & pricing- SONET in the enterprise

SONET rings in the backbone

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Summary

• What are the major trends in high-speed networking

• Why are carriers, residential consumers and enterprises demanding higher-speed services

• Which technologies will supply the required capacity and speeds?

• Contrast & compare: ISDN, T-1, T-3, Gig-E, SONET & ATM