AudioCodes MediaPack MP-40 series, User Manual

Page: 20 / 180

MediaPack BRI Series
User's Manual 20 Document #: LTRT-83702
1.4.3 Telephony Capabilities
1.4.3.1 Supplementary Services
The MediaPack SIP gateway supports the following supplementary services:
„
Hold / Retrieve; refer to ' Call Hold and Retrieve ' below.
„
Transfer (Refer and Replaces); refer to ' Call Transfer' on page 20 .
„
Call Forward (3xx Redirect Responses); refer to ' Call Forward' on page 21 .
„
Call Waiting (182 Queued Response); refer to ' Call Waiting' on page 21 .
The above services are permanently active and cannot be disabled.
For example setups of Supplementary Services, refer to Section ' Configuring
Supplementary Services ' on page 168 '.
1.4.3.1.1 Call Hold and Retrieve
Call Hold and Retrieve can be initiated by using the corresponding features of the ISDN
Phone.
Hold is performed by sending a REINVITE with the IP address 0.0.0.0 and ‘a=inactive’ in
the SDP.
The ISDN user can retrieve the call using the appropriate features of the ISDN phone.
1.4.3.1.2 Call Transfer
The system supports call transfer by the SIP side. The system supports the following two
types of call transfers:
„
Consultation Transfer (Refer and Replaces)
The common way to perform a consultation transfer is as follows:
In the transfer scenario, there are three parties: Party A = transferring, Party B =
transferred and Party C = transferred to.
•
A Calls B.
•
B answers.
•
A holds the call and dials a call to C.
•
A connects B to C, and then A disconnects.
•
After the transfer is complete, the B and C parties engage in a call.
„
Blind Transfer (Refer)
Blind transfer is performed after we have a call between A and B, and party A decides
to transfer the call to C immediately without speaking with C. It can do so by sending a
REFER message.
The result of the transfer is a call between B and C (similar to consultation transfer,
but skipping the consultation stage).