LANs to WANs: The Complete Management Guide

V

Variable bit rate (VBR), 232

Vendor and carrier services, 394–95

Very low bit rate voice (VLBRV), 195

Very small aperture terminals (VSATs), 377

Virtual Connection Services (VCS), 172

Virtual private networks (VPNs), 108, 158–64

advantages, 159–60

architecture, 160–61

automatic number identification (ANI), 162

billing options, 162–63

defined, 158

exchange number sharing, 162

features, 161–62

flexible routing, 162

history of, 159

local, service, 164

location screening, 162

network management, 163–64

originating call screening, 162

partitioned database management, 162

SDNs, 159, 160, 161

service providers, 160

vulnerability, 318

Viruses

multiplier effect, 319

protection, 318–20

scanning, 41–42

threat of, 319

Visio Professional, 345

VisualSAN, 89–90

Performance Manager, 90

VisualSAN Network Manager, 89–90

Voice compression, 194–95

Voice over ATM gateways, 118

Voice over frame relay (VoFR), 109, 230–31

Voice over IP (VoIP), 100

Voice systems

call detail reporting, 164–70

centralized vs. distributed, 156–58

Centrex, 177–81

historical perspective, 149–52

IP PBXs, 170–72

managing, 149–82

PBX components, 152–56

VPNs, 158–64

wireless PBX, 172–77