Oki 1.2 - Manual (Page 18)

10
Call transfer during a telephone call
You can transfer a call during a telephone call. To use this service, Use
PSTN line must be turned off.
• During a telephone call
Placing Calls
End-to-end service using DTMF signaling
DTMF signaling can be used via the IP network for answering machines,
etc. To use this service, Facsimile transmission using the VoIP line, must
be turned off.
• Making a telephone call