AASTRA 6700i series, 9143, 9480i, 9480i CT SIP Administrator Guide EN - Manual (Page 488)

41-001343-01 Rev 03, Release 3.2.2 5-211
Shared Call Appearance (SCA) Call Bridging
Shared Call Appearance (SCA) is when incoming calls are presented to multiple phones
simultaneously. For example, it is the ability to assign the boss' extension to a button on the
secretary's phone. Calls can be transferred between two phones with the same extension button by
simply putting the call on hold at one phone and picking it up on the other. Status LEDs light and
flash in unison, allowing all people sharing the extension to see the status at a glance.
The IP Phones include an enhanced SCA for the servers that support call bridging and allows two
or more SCA users to be connected in a call with a third party.
Refer to the following example.
Using the example above, when a call comes into Phone 1, Phone 2 and Phone 3 can pickup the
same call by pressing the SCA line key. Phone 2 and 3 display the call they are bridging into on the
LCD of the phones. Existing SCA parties in a bridge or one-to-one call hear an audible beep when
another party has joined the call.
If a phone is configured for SCA bridging and it attempts to join a call, but the account on the
server does not have this functionality enabled, an error message displays to the LCD on the
phone.
The SCA call bridging feature is disabled by default on all phones. You can enable this feature on
a global or per-line basis using the configuration files only.
Note: Enabling/disabling the beep is configurable on the server-side.
Note: A “Call-Info” header is included in the requests as well as the
200ok response to an INVITE, RE-INVITE, and UPDATE messages
for SCA lines.
Phone A
Phone 1
SCA Environment
Phone 2
Phone 3
Phone A calls the SCA number and
all the phones in the SCA enironment
ring.
SCA phone 1 answers.
SCA phone 2 joins by
pressing SCA line. When
When 2 and 3 pickup,
1 can hangup.
phone 1 hangs up, 2 is still
connected. Phone 2 can
press the line key to
Note: A user can place a call on hold while in an
put SCA call on hold
leaving 3 still connected
to 1.
SCA phone 3 joins by
pressing SCA line. When
phone 1 hangs up, 3 is still
connected. Phone 3 can
press the line key to
put SCA call on hold
leaving 2 still connected
to 1.
SCA bridged call, by pressing the SCA line key.