Auerswald COMpact 4000 Operation Manual page 601

Note: During sub-system operation, single-digit dialling may cause
problems. In this case, en-bloc dialling is usually enabled.
Connect audio through
The connection between the caller and the PBX is always created when a call is forwarded
externally. As a result, the caller will hear all replayed elements (tones, announcements) which
are played by the VoIP provider when the connection with the call forwarding destination is
established.
If external call forwarding is configured over a VoIP provider, the call tone may not be
replayed for the caller (the connection to the call forwarding destination number will therefore
be switched through in a "surprising" way).
Support T.38 for providers
Requirements:
• external VoIP channel that supports T.38 (optional, see Important Information > Product
Details > Basic Assembly and Extensions section)
• VoIP provider support for T.38
• Configured internal fax subscribers
T.38 (procedures for real-time Group 3 facsimile communication over IP networks) enables
smooth, extensive fax transmission to take place.
Note: If problems occur when T.38 is switched on, you can change the setting
used to negotiate the fax protocol (T.38 negotiation).
Compliant to RFC: two separate media lines for disabling audio and negotiating the fax
protocol.
Variant 1: only one media line for negotiating the fax protocol (the media line for disabling audio
is not used).
COMpact 4000 - Firmware V6.6A - Installation, Operation and Configuration V03 03/2016
T.38 negotiation
Settings
VoIP
VoIP Provider Settings
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