Avaya Definity SI, Maintenance Manual, Page: 2612 / 2968

Maintenance Object Repair Procedures
555-233-123 10-1826 Issue 4 May 2002
TTR-LEV (TTR Level)
A TN748 Tone Detector circuit pack and the TN744 Call Classifier circuit pack
provides touch tone receivers (TTRs or DTMR-PTs)) which are devices used to
interpret touch tone calling signals and to translate the dual tones into the
following valid digits: 0 through 9, *, and #. A Tone Detector circuit pack is a
resource shared by all PBX users. The term “touch tone” formerly bore an AT&T
trademark while the term “dual tone multifrequency receiver” has been the generic
term used for this kind of device. A Tone Detector circuit pack also has general
purpose tone detector ports (GPTD-PTs) to detect call progress tones, modem
answer tones, and transmission test tones. In G3iV1.1-286 or G3iV2-386, Call
Classifier Ports (CLSFY-PTs) have also been added to detect voice or network
intercept tones. A Call Classifier Port (CLSFY-PT) can function as either a
DTMR-PT or as a GPTD-PT.
When a user places a call from a digital or analog voice terminal on the switch, a
TTR is needed to interpret the dual tone multifrequency signals sent from the
voice terminal. The TTR is in use until the total number of digits needed is
collected or until a time-out occurs. Dial tone is supplied to a user after receipt of
an off-hook signal which signifies that a TTR is connected and ready to receive
digits. For example, if there are 20 TTRs in the system being used simultaneously
by 20 users at a given time, then the 21st user would not receive dial tone until a
TTR becomes available. It is for this reason that it is necessary to have sufficient
tone detectors in the system to prevent delay in receiving dial tone. The TTR-LEV
errors can be used to determine a shortage of tone detectors. Use the list
measurements tone-receiver command to determine tone detector usage. For
more information on this command, refer to Reports for Avaya MultiVantage
Software. The minimum threshold values assigned on the Maintenance-Related
System Parameters Form for TTRs (DTMR-PTs), CPTRs (GPTD-PTs), and CCRs
(CLSFY-PTs) should match the number of touch tone receivers (TTR) and tone
detectors (GPTD-PT) in the system. The numbers are four TTRs and two GPTDs
for each Tone Detector circuit pack [TN748, TN748B, and TN748C, and (the
TN756 Combined Tone Detector/Tone-Clock in a single-carrier cabinet system)]
used in the switch and 8 CCRs for each Call Classifier Port (TN744) circuit pack.
The threshold values are administered via the change system-parameters
maintenance command on the Maintenance-Related System Parameters Form.
The desired numbers are entered in the “TTR” (DTMR-PT), “CPTR” (GPTD-PT),
and “Call Classifier” (CLSFY-PT) fields, respectively.
MO Name (in
Alarm Log) Alarm Level
Initial Command to
Run Full Name of MO
TTR-LEV WARNING See Note
1
1 See the “Repair Procedure for the TTR Level Maintenance Object” section.
TTR Level