I

IDL (idle) state, 269

IETF (Internet Engineering Task Force), SIP and, 311

IMB (installation made busy) state

activating dedicated circuits and, 201

avoiding permanent, 271

understanding, 202, 270

in-band signaling

defined, 140

outpulse signal and start protocols, 137–139

incomplete dialing sequences, troubleshooting, 226–227

incremental billing, understanding, 96–97

incumbent local exchange carrier (ILEC), 11

independent sales agents, 18

information-only trouble tickets

avoiding IMB state, 271

versus tech assist, 273

infrastructure, old and new services fitting within existing, 23

Inmarsat (International Maritime Satellite Organization) calls, costs of, 52

inside wiring

available options, 63–64

dedicated service requirements, 59

local carriers and, 61–63

for newly ordered phone lines, 119

tips for dealing with, 64

installation

activating individual channels, 203

connecting hardware to carrier for activation, 202–203

identifying potential problems with, 205–206

introducing and reviewing conference call members for, 201–202

making test calls, 203

preparing for toll-free dedicated circuit, 198–200

recommended participants of toll-free dedicated circuit, 194–196

testing toll-free numbers, 204

height and, 205

installation fees

for dedicated circuits, 35, 36

reviewing for dedicated circuits, 92

reviewing for features and services, 93

of switched phone systems, 34

installation journal, maintaining, 200

installation made busy (IMB) state

activating dedicated circuits and, 201

avoiding permanent, 271

understanding, 202, 270

installation technician, activating toll-free dedicated circuit and, 195

Integrated Services Digital Network (ISDN) protocol

B and D channels of, 141–142

BRI circuits and, 143

domestic options for, 142

overview, 140–141

using for telemarketing, 142–143

interLATA calls, long-distance carriers and, 117

international calls

blocking, 31, 52

connect signal/call duration and, 106

fraud and, 38

making, 51–52

overview, 50–51

PDD and, 240

troubleshooting, 231

troubleshooting toll-free, 257–258

troubleshooting with dial-around codes, 243

international codes, 52

international faxes, troubleshooting, 231–232

International Maritime Satellite Organization (Inmarsat) calls, costs of, 52

International Telecommunications Union, H.323 protocol and, 311

international toll-free service (ITFS), troubleshooting, 257–258

Internet

finding local carrier on, 116

as information resource, 339–340

Local Calling Guide on, 339

National Do Not Call Registry on, 336

researching loopback plugs on, 345

researching MPLS on, 307

researching VoIP protocols on, 319

Internet Engineering Task Force (IETF), SIP and, 311

Internet Protocol (IP), VoIP and, 310

Internet service, evaluating need for, 15

Internet Service Provider (ISP), VoIP and, 310

InterOp questionnaire, 320–321

interoperability (InterOp) test, ordering VoIP service and, 320–321

intraLATA calls

long-distance carriers and, 117

making, 48

intrastate calls

making, 48–49

understanding rates for, 100

intrusive testing, by looping CSU, 274–279

invoices

checking call duration on, 106

checking for duplicate calls, 104–105

checking for international calls, 38

checking for long-duration calls, 104

checking for overlapping calls, 105–106

correcting long-distance-local carrier problems on, 120–121

finding old calls on, 106–107

importance of reviewing, 334

options for receiving, 102–103

reviewing summary pages on, 90–95

switching long-distance carriers and, 126–127

ISDN (Integrated Services Digital Network) protocol

B and D channels of, 141–142

BRI circuits and, 143

domestic options for, 142

overview, 140–141

using for telemarketing, 142–143

ISP (Internet Service Provider), VoIP and, 310

ITFS (international toll-free service), troubleshooting, 257–258