Oki Telephony Adapter - Manual (Page 17)

9 Placing Calls
Services
Third party incoming call during another call
You can respond to a third party’s incoming call while you are on
another call.
• A second party
telephone call.
• If a third party calls, a
notification tone is sent
to your telephone.
• You may speak to a
third party by hooking.
* The operation varies
depending on the data
settings. See Details of
Services p. 13