D


D channel made busy (DMB) state, 270

data (D) channels

ISDN protocol and, 141–142

made busy state of, 270

data link layer, of OSI model, 305

data streams, VoIP calls and, 312–314

data transfer

evaluating need for services, 14–15

evaluating requirements for, 296

need for, 295

using frame relay networks, 300–304

using modems, 296–297

using MPLS, 304–307

using private lines, 297–299

dead air, troubleshooting, 225

decimal rounding

two versus four, 96

understanding, 97–98

dedicated carrier pricing, contract negotiations and, 17

dedicated circuits

activating individual channels, 203

analyzing phone lines needed for long-distance, 24

areas of responsibility for, 207

balancing, 266

checking monthly recurring charges for, 92

comparing calls over with switched calls, 216–218

confirming/denying problems with hardware on, 284–285

connecting hardware to carrier for activation, 202–203

cost of long-distance, versus switched phone system, 36–37

identifying circuit variables in DS-1 circuits, 262

identifying circuit variables in DS-3 or larger circuits, 261

identifying DS-0 or individual channel problems, 262–263

identifying levels of potential problems with, 260

introducing and reviewing conference call members for activation, 201–202

line coding and framing and, 136–137

local, 16

local loop options for, 149

local loop pricing and, 146–148

maintaining installation journal for toll-free, 200

making test calls on, 203

managing trouble tickets for, 271–272

ordering carrier-provided local loops, 150–152

ordering customer-provided local loops, 152–157

ordering without local loops, 157–160

out-of-band signaling and, 141–146

outpulse signal and start protocols and, 137–139

preparing for installation of, 160

preparing for installation of toll-free, 198–200

preparing technical cut sheet for, 161–164

problems with, local loop and, 216

recommended participants of installation of toll-free, 194–196

requesting hot cut or parallel cut on, 194

testing toll-free numbers on new, 204–205

time division multiplexing and, 134–136

toll-free numbers and, 66–67

trunk groups and, 139

understanding call quality issues with, 263–265

understanding circuit failure, 265–266

understanding configuration of, 134

understanding costs of long-distance, 35–36

understanding installation fees for, 92

versus switched service, 15–17

dedicated service

building specific issues for, 60

necessary equipment for, 57–59

overview, 55

terminology of, 56

dedicated toll-free numbers. See also toll-free numbers

checking by redialing, 288–289

handling quality problems, 292

head-to-head testing, 291

identifying provisioning problems with, 287–288

negotiating hot cut without RespOrg, 191–192

ordering, 179–183

resolving activation without hot cut, 187–189

resolving cancellation before activation problem, 189–191

troubleshooting, 287

using hot cut to activate, 183–185

validating DNIS configuration four, 290–291

validating RespOrg, 289–290

versus switched, 165

default settings, hardware restoring to, 273

demarcation point (demarc)

inside wiring responsibility and, 62

looping CFA point and, 283–284

D4/SF, 137

dial tones

eliminating reorigination of, 38

with key system, 29

dial-around codes

avoiding problems with, 130

benefits of using, 128–129

forcing long-distance carrier use with, 127

functioning of, 239

no-PIC designation and, 129

troubleshooting with, 238–240, 241–243

understanding, 127–128

Dialed Number Identification Service (DNIS)

ordering toll-free numbers and, 180–181

toll-free service and, 80–81

understanding, 182

validating configuration, 290–291

Dialogic cards, synch problems caused by, 275

Direct-Inward Dialing (DID) service, dedicated long-distance circuits and, 16

disclaimer, CFA, 155

discounts, reviewing on invoice, 94

DLR (Design Layout Record), understanding for customer-provided local loops, 155–156

DMB (D channel made busy) state, 270

dropped calls, troubleshooting, 226

DS-1 circuit

identifying circuit variables and, 262

identifying problems with, 260

overview, 56

DS-3 circuit

identifying circuit variables in, 261

identifying problems with, 260

overview, 56

DS-0 circuit

identifying problems with, 260, 262–263

overview, 56

duplicate calls, checking for, 104–105




Telecom for Dummies
Telecom For Dummies
ISBN: 047177085X
EAN: 2147483647
Year: 2006
Pages: 184

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