Total Number Of Ttrs Required; Compensating For Slow Dial Tone (International) - AT&T MERLIN LEGEND Release 3.1 System Planning Manual

Selecting Line/Trunk Options

Compensating for Slow Dial Tone (International)

If this system is being installed outside of the U.S. , problems can arise because
of slow dial tone from local telephone companies due to the limitations of their
switching equipment. If this is the case, be aware of the following:
Users should be instructed to wait for dial tone before they dial. (Due to
changes made to internal timers, the system will allow the delay.)
The following features cannot be used:
— Automatic Route Selection
— Remote Call Forwarding
— Remote Access (outgoing)
— Tie trunks (configuration-dependent)
— Delay option on rotary lines
— Autodial, Last Number Dial, Saved Number Dial, and Callback queue
Also, the slow dial tone may cause problems with transferring a call,
joining a call, and end-to-end signaling.
Additional touch-tone receiver (TTR) boards may be needed for the
system. The number of TTRs can be increased by adding 400 GS/LS or
016 modules, each of which provides four TTRs or by adding 008 OPT,
012, 800 GS/LS-ID, or 800 DID modules, each of which provides two
TTRs.
To determine the number of TTRs needed, perform a traffic study on the number
of outgoing single-line telephone calls/busy hour, and the number of incoming
calls/busy hour routed to applications such as MERLIN MAIL. Then use Table
3-5 to determine the number of TTRs required.
Table 3–6. Total Number of TTRs Required
Calls per Hour
110
180
350
420
610
710
3–46
Lines/Trunks
0 sec 15 sec
4 4
6 6
8 10
8 10
10 12
10 14
Dial-Tone Delay
30 sec 45 sec
6 6
8 10
10 10
12 14
14 16
16 18
60 sec 75 sec
8 8
10 10
14 14
14 16
18 20
20 22