User's Manual 248 Document #: LTRT-65417
MP-11x & MP-124
24.4 Call Transfer
This section describes the device's support for call transfer types.
24.4.1 Consultation Call Transfer
The device supports Consultation Call Transfer using the SIP REFER message and
Replaces header. The common method to perform a consultation transfer is described in
the following example, which assumes three call parties:
Party C = transferred to
1. A Calls B.
2. B answers.
3. A presses the hook-flash button and places B on-hold (party B hears a hold tone).
4. A dials C.
5. After A completes dialing C, A can perform the transfer by on-hooking the A phone.
6. After the transfer is complete, B and C parties are engaged in a call.
The transfer can be initiated at any of the following stages of the call between A and C:
Just after completing dialing C phone number - transfer from setup
While hearing ringback – transfer from alert
While speaking to C - transfer from active
24.4.2 Blind Call Transfer
Blind call transfer is done (using SIP REFER messages) after a call is established between
call parties A and B, and party A decides to immediately transfer the call to C without first
speaking to C. The result of the transfer is a call between B and C (similar to consultation
transfer, but skipping the consultation stage).
24.5 Call Forward
The following methods of call forwarding are supported:
Immediate: incoming call is forwarded immediately and unconditionally.
Busy: incoming call is forwarded if the endpoint is busy.
No Reply: incoming call is forwarded if it isn't answered for a specified time.
On Busy or No Reply: incoming call is forwarded if the port is busy or when calls are
not answered after a specified time.
Do Not Disturb: immediately reject incoming calls. Upon receiving a call for a Do Not
Disturb, the 603 Decline SIP response code is sent.
Three forms of forwarding parties are available:
Served party: party configured to forward the call (FXS device).
Originating party: party that initiates the first call (FXS or FXO device).
Diverted party: new destination of the forwarded call (FXS or FXO device).