25
6.
Ringing delay: the maximum number of ring before automatic answering is 5.
7.
Ringer Equivalent Number (REN) = 1
The REN is a custumer guide indicating appoximately the maximum number of items of apparatus that
should be connected simultaneously to the line.
The sum of the REN’s of the individual items should be not exceed 4. The REN value of a BT telephone is
assumed to be 1 unless otherwise marked.
8.
The voltage drop introduced by the apparatus between the PSTN and the associated telephone is 2.0 Volts
dc therefore no additional series equipment may be connected.The introduction of this voltage drop may
occasionally cause difficulties in making calls from the associated telephone or problems in telephone
conversation being experienced by both parties to the call.
While operation may be possible initially, change to or modernization of the network taking place in the
normal course of events may result in the apparatus being connected to be compatible. failure of the
apparatus to wok under these circumstances may not be responsibility of the network operator.
In the unlikely event of such problems occuring, the user should contact the supplier or maintainer of the
apparatus.
Difficulty may be experienced when making calls from other apparatus. such difficulties may include:
- Difficulties in making call
- Problems in telephone conversation being experienced by both parties to the call.
Note : The definition of RBS (Relevant branch system) for PSTN lines is given in BS6789 section 6.1
(1986) clause 2.4.
9.
Naive caller
"Callers are accustomed to being answered normally within 10s and that the majority abandon calls that are
not answeed within 45 s".
It is "normal" to set the number of rings beetween 1 to 5 rings before the answering machine responds.
The machine is already preset for a plug and play mode.
"If the intention is to delay answer so that normal voice callers would abandon the call before the non-voice
TE answered, then the delay should at least 45 s".
It is helpful to include the statement of the answering telephone number with the exchange name or
international code and that the announcement must be sutable for the purpose for which it is intented. The
announcement should also start within 3s of answering.
Paytone may be received after answering calls from some types of payphones and may persist forr up to 13 s
and the answering announcement should be constructed so as to ensure that an answering announcement
containing the identity of the called line and, where appropriate, the invitation to record, will be heard by the
callers after paytone has ceased.
IMPORTANT ! Compatible switchboards
Your terminal is approved only for use with the compatible switchboard including those which do not
provide secondary proceed indication. If you would like a list suitable switchboards, contact BT on 0800 800
152.
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