Ringback Test An automated system. The tester dials a number at the CO, then hangs up. The CO equipment then calls the number that the tester called from.
ANAC Automatic Number Announcement Circuit Dial the ANAC number, and a computer generated voice speaks the number of the line you're testing Often accomplished by Caller ID now ANAC works on unlisted numbers
DATU Direct Access Testing Unit Allows you to do user-controlled tone generation tests See next slide, "DAMT"
DAMT Direct Access Mechanized Testing Allows you to do user-controlled tone generation tests See previous slide, "DATU"
Echo Test Repeats every tone you generate Useful for verifying that you are generating valid DTMF tones
Check Clocking #1 Also called "synchronization" On a T1, improper clocking may produce a "Sync" error light On a T1, improper clocking may produce a high BER (Bit Error Rate)
Check Clocking #2 On a voice circuit, improper clocking can be heard on the phone or with a butt set as clicking sounds On a data circuit, improper clocking may show up as random data loss or data errors
Bit Error Rate Not always related to clocking Digital equivalent of signal-to-noise ratio S/N ratio can be measured on digital voice circuits in the analog portion BER can be measured on all digital circuits, whether voice or data Causes: line loss, reflection, other
ISDN Troubleshooting #1 Verify that the SPID is programmed correctly SPID = Service Profile Identifier Assigned by the service provider Programmed in the ISDN "modem" or terminal adaptor
ISDN Troubleshooting #2 Verify that the LDN is programmed correctly LDN = Local Directory Number Assigned by the service provider Programmed in the ISDN "modem" or terminal adaptor
ISDN Troubleshooting #3 Verify that the terminator is installed (Contains two 100 ohm resistors: pins 4 & 5, pins 3 & 6)
ISDN Troubleshooting #4 Make sure the proper encoding format is programmed For North America, -law For UK and Europe, a-law