F

facilities-based long-distance carriers, 12

faxes

compressing VoIP, 316

problems with international, 231–232

Feature Group D (FGD) protocol, 145–146

features

reviewing installation fees for, 93

reviewing monthly recurring charges for, 92–93

female loopback plugs, making, 344

fiber cuts, handling, 230

finger-pointing, avoiding during troubleshooting, 331–332

Firm Order Commitment (FOC) document

ordering carrier-provided local loops and, 151–152

understanding, 328

flat rates, versus tiered rates, 98

forging, letter of authorization, 174

four-decimal rounding

importance of, 97

versus two-decimal rounding, 96

frame relay cloud, function of, 301

frame relay networks

bandwidth needs, 303–304

data transfer using, 300

disadvantages of, 300–301

local loop and, 301–302

PVCs and, 302–303

frame relay ports, function of, 302

framing, dedicated circuits and, 136–137

framing slips, 264–265

fraud

credits after, 332

long-duration calls and, 104

preventing calling card, 39–40

preventing PBX hacking, 38

understanding/preventing, 37–38

fraud block, fixing, 121