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Direct Outward Station Access (DOSA) allows an incoming caller to enter a password and be
connected to a different outside line within the system and make an outgoing call. The original
incoming call must be directed to a CO line which is programmed to operate in the DISA mode
(See “Choices In Con
fi
guring Central Of
fi
ce (CO) Lines” on page 46).
After the system answers the incoming call in the DISA mode, the caller should dial a “6” or
a “7”, followed by the 6-digit DOSA password. If the password entered matches the password
stored in memory, a connection will be made to the
fi
rst available CO line listed in Outgoing Call
Group #4 (See “De
fi
ning Outgoing Call Groups” on page 57).
If the incoming caller entered a “6”, the system must detect a DTMF digit within 35 seconds in
order to allow the connection to continue. If no digit is detected after 20 seconds, a beep tone
will be heard. When a digit is entered the beep tone will cease. Thereafter the beep tone will be
heard every 4 minutes and a DTMF digit must be entered within 15 seconds to continue the call.
This will prevent the situation where the incoming caller hangs up and the system is connected
to the CO line inde
fi
nitely. In all cases, the call will be terminated in 15 minutes or when a Clear
Forwarding / Polarity Reversal signal is detected, if enabled.
If the incoming caller entered a “7” followed by the 6-digit password, the operation is exactly the
same as for a “6” except there will be no prompts for DTMF digits. This can facilitate fax and data
transfers via DOSA since it would be impossible to enter a DTMF digit during data transmission.
The “6” entry is still preferred for voice conversation so that the CO line can be released in a short
time after the conversation has ended.
If the outgoing CO line (to which DOSA is connected) is con
fi
gured for pulse dialing, any digits
entered by the caller will also be output as pulses. This conversion of DTMF to pulses will continue
until either a “*” or “#” digit is entered. Thus the “*” or “#” are the preferred entry when responding
to the disconnect warning signal so that there will not be any pulses output on the CO line.
Direct Outward Station Access (DOSA)
Direct Outward Station Access (DOSA)
