Lucent Technologies 6.1 manual System Requirements for Touch-Tone Receivers, TTRs Required

MERLIN LEGENDCommunications System Release 6.1	Issue 1
System Planning 555-661-112	August 1998

2Control Unit Configuration

Numbering the System Page 2-18

Table 2–4 estimates the total number of TTRs required in the system, based on call volume and whether the system uses account codes. The call volume per hour in this table includes all calls originating from single-line telephones, calls on tie lines, incoming remote access and Direct Inward Dial (DID) calls.

NOTE:

You must consider the call traffic across a private network when estimating the number of required TTRs. This includes calls on analog tandem tie trunks and T1-emulated tandem tie trunks. In addition, if your private network includes Centralized Voice Messaging, you must consider the call traffic coming across the private network for the voice messaging system and the TTRs required for the updating of Message Waiting lights (Release 6.1 or later systems). For this updating, a TTR is required at the sending end and the receiving end. If the systems in the private network are connected by PRI trunks, no additional TTRs are needed.

Table 2–4.		System Requirements for Touch-Tone Receivers
		TTRs Required
	Calls/Hour	No Account Codes	Account Codes Used
	110	2	4
	180	4	6
	350	4	8
	420	6	8
	610	6	10
	710	8	10

In Release 6.0 and later systems, the use of the Prompt-Based Overflow setting, which allows callers to request overflow coverage while waiting in a calling group queue, requires TTRs for primary and secondary delay announcement devices that present the option to callers.

Table 2–5 shows the TTRs required for primary delay announcement devices when using the Prompt-Based Overflow setting.