Three situations can follow the transfer:
1.A quick confirmation tone (temporarily using the call waiting indication tone) followed by a dialtone. This indicates the transfer was successful (transferee has received a 200 OK from transfer target). A can either hang up or make another call.
2.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 indicates the transfer has failed.
3.Busy tone keeps playing. This means we have failed to receive the second NOTIFY from the transferee and the call has timed 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 situation occurs. In bad network scenarios, this could also happen, although the transfer may have been completed successfully.
Attended Transfer
This function is applicable on the FXS port for VoIP calls only. Assume that parties A and B are in conversation. Party A wants to Attend Transfer Party B to C:
1.A presses FLASH on the analog phone to get a dial tone;
2.A then dial C’s number followed by #.
3.If C answers the call, A and C are in conversation. Then A can hang up to complete transfer.
4.If C does not answer the call, A can press “flash” back to talk to B.
NOTE: When Attended Transfer fails and A hangs up, the HT503 will ring user A back again to remind A that party B is still on the call. Party A can pick up the phone to resume a conversation with party B.
3-way Conferencing
The HT503 supports Bellcore Style
Assume that parties A and B are in conversation. Party A (using the HT503) wants to bring C into a 3- way conference:
1.A presses FLASH (on the analog phone, or Hook Flash for old model phones) to get a dial tone.
2.A dials C’s number then # (or wait for 4 seconds).
3.If C answers the call, then A presses FLASH to bring B, C in the conference.
4.If C does not answer the call, A can press FLASH back to talk to B.
5.If A presses FLASH during the conference, C will be dropped out.
6.If A hangs up, the conference will be terminated for all three parties when configuration “Transfer on Conference Hangup” is set to “No”. If the configuration is set to “Yes”, A will transfer B to C so that B and C can continue the conversation.
PSTN Pass Through
HT503 supports PSTN pass through using the FXS port. The user can place and receive PSTN calls using analog phone connected to FXS port.
Grandstream Networks, Inc. | HT503 User Manual | Page 12 of 38 |
| Firmware 1.0.4.2 | Last Updated: 06/2011 |