Transcript ppt
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 1 VPNs & Specialized Network Services continued • ATM compared to IP • SONET – In the backbone – In the metropolitan area – Compared to gigabit ethernet 2 virtual private networks Virtual: from the Latin excellence; Essence though not in fact actual 3 IPSec virtual private network for remote access •What are the advantages of VPNs? •Why are they important? •How can they be made secure? 4 Key Components of Frame relay 5 Multipoint private lines with hub and spoke for small locations •Why use private lines rather than a virtual private network? 6 Mesh network topology pros & cons 7 Mesh; hub & spoke combo Any-to-any mesh design in a VPN; hub and spoke (star) to headquarters for Internet access. 8 Local and interexchange channels of a private line •Billing, repair & installation ramifications 9 Integrated access device for T-1s carrying voice and data •Small & medium companies •Implication of competition 10 T-1 and E-1 • 1.544 or 2.048 Megabits per second – Bell Standard – IT Standard • Applications 24 or 30 channels 24 or 30 channels T-1 Mux T-1 Mux Fiber, copper or wireless media 11 28 T-1s = a T-3 Circuit Internet Boston ISP T-1 Dallas T-3 T-1 Fiber or Wireless London 12 Videoconferencing using three bonded BRI ISDN circuits 13 BRI ISDN bonding 14 Primary rate interface ISDN • 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. 15 DSLAMs in digital loop carriers (remote terminals) 16 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 data voice downstream upstream 17 DSLAM connection to an Internet service provider 18 Figure 5.14 Neighborhood mini remote access multiplexers (MiniRAMs). 19 Gigabit Ethernet fiber-optic cabling and metropolitan fiber rings 20 Leasing wavelengths in the metropolitan area 21 Parallel streams in an ATM circuit •Fixed size cells •Quality of service •Asynchronous switching •In the frame relay backbone 22 SONET rings in the backbone - bidirectional duplicate rings in a carrier’s backbone network - The fiber glut & pricing - SONET in the enterprise 23 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 24