Comdial DSU II Manual page 13

DSU II Digital Telephone System
To enable this feature enhancement, programmers must first enable tone first signalling
and arrange an intercom hunt group. Then, they can individually enable call forwarding
for RNA calls and call forwaring for busy calls. They can turn on either call forwarding
scheme alone or turn on both schemes as the site demands dictate.
Ring-No-Answer Forwarding Of Transferred Calls
This feature enhances the existing automatic RNA call forwarding feature to include
forwarding of transferred lines to individual stations. When a telephone user transfers a
line to a station, the call will ring at the station receiving the transfer for the programmed
number of rings. After that, the call will start ringing at the station that is hunt-linked to
the station first receiving the transfer. If that station is also hunt-linked to another station,
the call will follow that link. When the transfer recall time expires, the call will recall
back to the station that initiated the transfer. The hunt link can be a circular one. The
transferred line will circle the hunt link until it recalls. Alternately, the station can be
hunt-linked to voice mail so that a transferred call will forward to the station's voice mail
box if it is unanswered. For this feature to work properly, the following details must be
considered:
• you must hunt-link the station receiving a transfer to another station;
• you must program the number of rings to occur before forwarding;
• you must insure that the transfer recall time is larger than the total time of RNA to
all hunt linked stations (if it is not, the transferred call will recall before the call
gets to the end of the hunt link).
For an example of this last consideration, assume station 12 is hunt-linked to station 13
which is also hunt-linked to station 14. Further assume that station 12 and 13 have their
RNA's set to two rings. A call that is transferred to station 12 will ring there twice, then
it will ring at station 13 twice, then it will ring station 14 until transfer recall time expires.
Each transfer ring cycle is approximately four seconds; therefore, the line will ring the
station for approximately eight seconds before it moves to the next station. Since there
are three stations linked together, this event will require 24 seconds. This means that you
should set the transfer recall time for 25 seconds or higher.
You can use this formula to determine minimum transfer recall time:
If:
4 = transfer ring cycle time in seconds
R = how many RNA rings assigned per station
S = how many stations are in hunt list
Then:
4 x R x S = minimum transfer recall time
Digital Telephone System Features A – 13
IMI66–132