SERVICE MANUAL AS55X
55Xseries_manual_V3.22 (18-08-15)
www.kuhnt.com
7
1
General functions
1.1
Fax via GSM
It is possible to send and receive faxes over the GSM mobile phone network using a custom
G3-fax machine. You can use the WLL550 Pro gateway with integrated FXO or any
AS55x/WLL550 VoIP gateway with an analog telephone adapter via a dedicated SIP-channel.
Normally fax transmissions over the GSM network are critical because the handshake is not
optimized fir it. For better results the WLL550 Pro buffers the transmission process and splits
it into two phases. First the fax document will be submitted from the sending machine to the
WLL550 Pro's memory and then time-delayed from the WLL550 Pro memory to the receiving
fax station. The WLL550 Pro will try up to three attempts to submit a fax. During this time
the channel LED is flashing continuously and no further call is possible via this channel.
However a fax transmission can fail for some reason and by splitting the transmission it
might happen that the first phase of the transmission is successful but the second phase
fails. To ensure that the sender gets information about the unsuccessful transmission the
WLL550 Pro can generate a receipt for all successful and failed fax transmissions via a
response fax.
For using the fax service a SIM card with activated GSM-fax service is mandatory. Ususally
you will get a separate fax number from your service provider (also called multi-numbering).
All incoming fax calls will be forwarded automatically to the analogue fax port or the SIP fax-
channel. Outgoing faxes will be forwarded via a GSM-channel (UMTS and LTE do not support
the GSM fax service).
For programming instructions see 5.5.
1.2
Callback
Due to the restrictions of displaying the CLIP within GSM networks ( ‘CLIP -no screening’ is
not available and only a GSM number can be transmitted) a called party does not know
which PBX subscriber is calling via the AS55X or who has initiate the call-setup. The called
subscriber however, cannot reach the call initiator for a call back, because all subscribers of
the PBX could have initiated this call. For this purpose the AS55X can record calls or call
setup data.
All call-setups could be saved, so the AS55X can backtrack every call setup’s origin. The
called party initiates a call to the transmitted CLIP number (one GSM number of the AS55X)
and by using of the call-setup list the callback can be routed the original subscriber of the
PABX. Please consider that only the last call to one destination can be saved. A previous
existing call-setup will always be overwritten by the new one. It is mandatory that both sides
transmit their number (CLIP).
For programming instructions see 5.8.2, 5.8.3, 5.10.2 and 7.5.
Summary of Contents for AS55 Series
Page 1: ...AS55X Series SERVICE MANUAL ...
Page 2: ......
Page 18: ...SERVICE MANUAL AS55X 16 www kuhnt com 55Xseries_manual_V3 22 18 08 15 ...
Page 173: ...www kuhnt com 1 Personal memo ...
