Instruction manual

MERLIN LEGEND Communications System Release 5.0
System Planning
555-650-112
Issue 1
June 1997
Control Unit Configuration
Page 2-16Numbering the System
2
Table 2-3. Touch-Tone Receivers Required by Voice Messaging Systems
The number of TTRs required by the system depends on the call volume for all
incoming calls on remote access, direct inward dial (DID) trunks, and T1 data
channels (planning information about trunks is provided in Chapter 3,
‘‘Lines/Trunks’’), outgoing calls on single-line telephones, and tie lines. In addition,
if account codes are used, additional TTRs are required for the single-line
telephones. Table 2–4 gives estimates for the total number of TTRs required in
the system based on call volume and whether the system has a VMS and uses
account codes. The call volume in this table includes all calls originated from
single-line telephones, calls on tie lines, incoming remote access and direct
inward dial (DID) calls, and calls routed to the VMS.
Table 2-4. System Requirements for Touch-Tone Receivers
To calculate the total number of TTRs that are required by the system, do the
following:
1. If the system has a VMS, use Table 2–3 to find the number of TTRs
required by the system to support the VMS. If the system does not have a
VMS, then proceed to Step 2.
2. Estimate the hourly call volume for all calls originating from single-line
telephones, incoming calls on Remote Access, DID lines, T1 data lines,
and calls on tie lines.
3. Use Table 2–4 to find the system requirements for TTRs based on the
hourly call volume estimated in Step 2.
Number of VMS Ports
Number of TTRs
Required
11
21
32
42
63
84
12 6
Calls/Hour
No Account
Codes
Account Codes
Used
110 2 4
180 4 4
350 4 4
420 6 8
610 6 6
710 8 8