AT&T MERLIN LEGEND Release 4.0 Feature Reference page 560

Feature Reference
A touch-tone receiver (TTR) is required to make calls from tip/ring equipment or
to use the Remote Access feature. TTRs are provided on 400, 400 GS/LS, 800
DID, 008 OPT, 800 GS/LS-ID, 016, and 012 modules. Normally, these TTRs are
sufficient to handle the calls originated from these modules. However, additional
TTRs may be needed to support the following services:
Tie trunks and DS1-emulated tie trunks set for DTMF signaling
Remote Access
Account Code Entry
Authorization Codes
IS II/III AUDIX Voice Power
IS II/III Integrated Voice Power Automated Attendant
IS III FAX Attendant
MERLIN MAIL
AT&T Attendant
Conversant
Intuity
If more TTRs are needed to support these services, 400 GS/LS modules can be
added (each module provides four TTRs). Table 41 shows the estimated
number of TTRs needed, depending on the call volume and the type of service.
Table 40 is based on the assumption that the system already has basic
telephones, Remote Access, and tie trunks.
Table 41. Number of TTRs Required
Calls per Hour
110
180
350
420
610
710
The touch-tone receiver (TTR) is allocated for 15 seconds at the beginning of
the call and decreases to 5 seconds as the number of digits dialed increases.
Each time the user presses another digit, the TTR timer decreases. If the user
does not dial a digit within the time frame, the TTR is removed from the call and,
after about 24 seconds, the call is disconnected and the user hears a recording
or a fast busy.
560
Touch-Tone or Rotary Signaling
No Acct. Codes Acct. Codes
or VMS/AA or VMS/AA
2
4
4
6
6
8
Acct. Codes
and VMS/AA
4 6
6 8
8 10
8 10
10 12
10 14