Hello :
http://wiki.freeswitch.org/wiki/Misc._Dialplan_Tools_att_xfer
I found this example seems not an "attended transfer" , rather
a consultation hold.
An ext 1527 --> call ext 1528 , then 1528 press "*3" , and keyin "1529#"
1527 into holding state listening music, 1528 and 1529 bridged
if 1527 hungup , all disconected , only on 1529 hangup , 1527 go back with 1528
>From the following
ftp://ftp.rfc-editor.org/in-notes/internet-drafts/draft-ietf-sipping-service-examples-15.txt
2.2. Consultation Hold
Alice Proxy Bob Carol
| | | |
| INVITE F1 | | |
|--------------->| INVITE F2 | |
| |------------->| |
|(100 Trying) F3 | | |
|<---------------|180 Ringing F4| |
| |<-------------| |
| 180 Ringing F5 | | |
|<---------------| 200 OK F6 | |
| |<-------------| |
| 200 OK F7 | | |
|<---------------| | |
| ACK F8 | | |
|--------------->| ACK F9 | |
| |------------->| |
| Both way RTP Established | |
|<=============================>| |
| |INVITE(hold) F10 |
|INVITE(hold) F11|<-------------| |
|<---------------| | |
| 200 OK F12 | | |
|--------------->| 200 OK F13 | |
| |------------->| |
| | ACK F14 | |
| |<-------------| |
| ACK F15 | | |
|<---------------| | |
| No RTP Sent! | |
| | INVITE F16 | |
| |<-------------| |
| | | INVITE F17 |
| |--------------------------------->|
| |(100 Trying) F18 |
| |------------->| |
| | | 180 Ringing F19 |
| |<---------------------------------|
| | 180 Ringing F20 |
| |------------->| |
| | | 200 OK F21 |
| |<---------------------------------|
| | 200 OK F22 | |
| |------------->| |
| | ACK F23 | |
| |<-------------| |
| | | ACK F24 |
| |--------------------------------->|
| | Both way RTP Established |
| | |<=================>|
| | BYE F25 | |
| |<-------------| |
| | | BYE F26 |
| |--------------------------------->|
| | | 200 OK F27 |
| |<---------------------------------|
| | 200 OK F28 | |
| |------------->| |
| | INVITE F29 | |
| INVITE F30 |<-------------| |
|<---------------| | |
| 200 OK F31 | | |
|--------------->| 200 OK F32 | |
| |------------->| |
| | ACK F33 | |
| |<-------------| |
| ACK F34 | | |
|<---------------| | |
| Both way RTP Established | |
|<=============================>| |
| BYE F35 | | |
|--------------->| BYE F36 | |
| |------------->| |
| | 200 OK F37 | |
| |<-------------| |
| 200 OK F38 | | |
|<---------------| | |
| | | |
In this scenario, Alice calls Bob. Bob places call on hold. Bob
calls Carol. Bob then disconnects with Carol, then takes the call
with Alice off hold. The call ends when Alice hangs up.
2.5. Transfer - Attended
Alice Bob Carol
| | |
| INVITE F1 | |
|--------------->| |
| 180 Ringing F2 | |
|<---------------| |
| 200 OK F3 | |
|<---------------| |
| ACK F4 | |
|--------------->| |
| RTP | |
|<==============>| |
|INVITE (hold) F5| |
|<---------------| |
| 200 OK F6 | |
|--------------->| |
| ACK F7 | |
|<---------------| |
| No RTP | |
| | INVITE F8 |
| |------------->|
| | 180 Ringing F9
| |<-------------|
| | 200 OK F10 |
| |<-------------|
| | ACK F11 |
| |------------->|
| | RTP |
| |<============>|
| |INVITE (hold) F12
| |------------->|
| | 200 OK F13 |
| |<-------------|
| | ACK F14 |
| |------------->|
| | No RTP |
| REFER Refer-To: C F15 |
|<---------------| |
|202 Accepted F16| |
|--------------->| |
| NOTIFY F17 | |
|--------------->| |
| 200 OK F18 | |
|<---------------| |
| INVITE Replaces: B F19 |
|------------------------------>|
| 200 OK F20 |
|<------------------------------|
| ACK F21 |
|------------------------------>|
| RTP |
|<=============================>|
| | BYE F22 |
| |<-------------|
| | 200 OK F23 |
| |------------->|
| NOTIFY F24 | |
|--------------->| |
| 200 OK F25 | |
|<---------------| |
| BYE F26 | |
|<---------------| |
| 200 OK F27 | |
|--------------->| |
In this scenario, Alice calls Bob. Bob puts Alice on hold then calls
Carol to announce transfer, then places Carol on hold. Bob transfers
Alice to Carol which replaces the session between Bob and Carol.
thanks!