Protocol Sequence
After ringing detection, the machine sends a pre-recorded message, and at
the same time, starts to detect CNG signals or DTMF tones from the remote
caller. The dedicated DTMF receiver on the MFDU is used to detect both
CNG signals and DTMF tones.
If the machine detects CNG signals, the machine goes into fax reception
mode. If the machine detects DTMF tone signals, the machine then sends
some more messages to instruct the caller what to do. After the last message
has been sent to the remote caller, the machine goes into fax transmission
mode.
Sometimes the machine might not detect DTMF signals while the machine is
transmitting a voice message. To avoid this, the messages should instruct the
caller to send DTMF signals after the message has been finished.
While Fax On Demand is enabled, the machine disables receiving Transfer
Request using DTMF tones, because it may use the same key sequence.
CNG
CNG
CNG
CED
NSF
DIS
Message
"This is a fax service ... "
Tx
Rx
Dial
Ring Detection
Message
"This is a fax service ... "
Tx
Rx
Dial
Ring Detection
" 1 "
" 5 "
" # "
Box No.
Specified
Message
" # "
" # "
No Box No.
Specified
Message
"Press Start ..."
CED
NSF
DIS
DIS or NSF
CNG/DTMF Detection
CNG/DTMF Detection
H515D523.wmf
Detai
led De-
scr
ip
ti
ons
December 21st, 1995
DETAILED SECTION DESCRIPTIONS
SYSTEM FEATURES
2-67