Grandstream Networks GSM gateway - Manual (Page 12)

Februaray-2006 Page 12 / 42
MasterVoIP
VoIP to GSM Gateway
3.1.4.3 Blind Transfer
Assuming that call party A and B are in conversation. A wants to Blind Transfer B to C:
1. A presses FLASH (on the analog phone, or Hook Flash for old model phones) to get a dial tone.
2. Then “A” dials *87 then dials C’s number, and then # (or waits for 4 seconds)
3. “A” can hang up.
Note: Call Feature has to be set to YES.
“A” can hold on to the phone and wait for one of the three following behaviors:
 A quick confirmation tone (temporarily using the call waiting indication tone) followed by a
dial tone. This indicates the transfer is successful (transferee has received a 200 OK from
transfer target). At this point, “A” can either hang up or make another call
.
 A quick busy tone followed by a restored call (on supported platforms only). This means the
transferee has received a 4xx response for the INVITE and we will try to recover the call. The
busy tone is just to indicate to the transferor that the transfer has failed.
 Busy tone keeps playing. This means we have failed to receive the second NOTIFY from the
transferee and decided to time out. Note: this does not indicate the transfer has been successful, nor does it indicate the
transfer has failed. When transferee is a client that does not support the second NOTIFY (such as our own earlier
firmware), this will be the case. In bad network scenarios, this could also happen, although the transfer may have been
completed successfully.
3.1.4.4 Attended Transfer
Assuming that call party A and B are in conversation. A wants to Attend Transfer B to C:
1.
“A” presses FLASH (on the analog phone, or Hook Flash for old model phones) to get a dial tone
2. “A” then dial C’s number then # (or wait for 4 seconds). “A” and “C” now are in conversation.
3. “A” can hang up.
Note:
When intended Transfer failed, if “A” hangs up, the HandTone-496 will ring user “A” again to
remind “A” that “B” is still on the call, by pressing FLASH or Hook again will restore the
conversation between “A” and “B”.
.