Copyright 2010-2017 Obihai Technology, Inc.
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As transferor, if the call with the transferee is on SP
m
and the call with the transfer target on SP
n
where SP
m
and SP
n
point to the same ITSP Profile
X
(including the case
m
=
n
) and
ITSP Profile X
–
General
::
SignalingProtocol
is SIP and
ITSP Profile X
–
SIP
::
X_UseRefer
is
true
, the phone will attempt to transfer the call by sending a REFER request to
the transferee with the transfer target’s SIP URL in a Refer
-To header. For other cases, the phone will try to bridge the
transferee and transfer target call legs internally.
Limitations of Transfer by Internal Bridging
The phone acts as a proxy of RTP packets sent by each peer of the bridge, without any transcoding. While the phone
will try its best to negotiate the codec to use with each call peer that would be acceptable by the other peer, the
administrator should understand this limitation and configure the codec profiles accordingly. For example, if Google
Voice is to be used, then a call transfer involving a Google Voice call leg must make sure the other call leg supports the
G711U codec.
Conference Calls
A conference call is a conversation involving 2 or more remote parties. In order to start a conference, there must be at
least two calls and with at least one of them in the Connected State and one of them in the Holding State . The
following picture shows such scenario with two calls. To start a conference, highlight one of the calls in the Holding
State and select the
Add to Conf
soft-key option.
OBi1000 phones support two methods to conference multiple parties: a) local mixing/bridging and b) external
conference bridge. The user interface is slightly different in each case as described below.
Local Mixing/Bridging
After starting a 3-way conference as described earlier, the user can see the two remote parties both in the Connected
State.
The OBi1000 supports up to 4-way conferencing (with 3 remote parties) using the local mixing/bridging method. To add
a third remote party, make a new call to the target party (or answer a new incoming call from another remote party, if
applicable), which automatically places the two connected calls on hold. When the target party rings or answers,
resume the two original conferees (one at a time by highlighting each holding call on screen and applying the
Add to
Conf
soft-key option to it). Eventually you will have a 4-way conference with three calls in the Connected State.
With locally mixed N-way calls, user can see N individual call items on the screen, one for each call-leg of the N-way call.
Hence the user can also individually control each call-leg, such as holding or ending any one of them. Two additional
features that are useful in this scenario are Call Selective Mute and Coachee Mode as described below.
Call Selective Mute