LG G5310 Guide De L'utilisateur page 190

Additional Functions
1-8 Switching DTMF Tones on During a Call
To turn DTMF tones on during a call, for example, to allow your
handset to make use of an automated switchboard, select the
[Options] key, then DTMF On. DTMF tones can be turned off the
same way.
1-9 Calling up the messages or SIM Tool Kit
The Messages and SIM Tool kit main menu options can be reached
from the in-call menu by selecting the [Options] key, then Messages
or SIM Tool Kit (Screen name depends on the network operator's
SIM). SIM Tool kit menu is shown only when SIM in the handset
supports SIM Tool kit service.
2 Multiparty or Conference Calls
The multiparty or conference service provides you with the ability to
have a simultaneous conversation with more than one caller, if your
network service provider supports this feature.
A multiparty call can only be set up when you have one active call
and one call on hold, both calls having been answered. Once a
multiparty call is set up, calls may be added, disconnected or
separated (that is, removed from the multiparty call but still
connected to you) by the person who set up the multiparty call.
These options are all available from the in-call menu and are listed in
Section.
The maximum callers in a multiparty call is five. Once started, you
are in control of the multiparty call, and only you can add calls to the
multiparty call.
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