Udit,

If you want to implement a Attended transfer, you could play an announcement, something
to the effect of "the transfer failed" by the transferor, and then send the BYE.


Ofcourse if you don't care about that kind of feature, (ex. for blind transfer), then you could
send the BYE before talking the call out of hold.


Nagesh Shekar

[EMAIL PROTECTED] wrote:


Nagesh,

My question was why Transferor is sending INVITE (unhold) when NOTIFY (486 Busy) is received.
It can directly send BYE message.


-Udit


Nagesh Shekar <[EMAIL PROTECTED]>

04/20/2005 06:35 PM
Please respond to
[EMAIL PROTECTED]


To Udit Goyal/C/US/[EMAIL PROTECTED] cc SIP Implementors <[email protected]> Subject Re: [Sip-implementors] Failure transfer scenario









Udit,

NOTIFY is required to end the impicit subscription that is created by
the Transferor,
when it sends the REFER out.

Shekar

[EMAIL PROTECTED] wrote:

>In the SIP CC Transfer, for failure transfer cases, why transferor sends
>INVITE(unhold) followed by BYE
>on receiving NOTIFY (with failure status).
>
>It can directly send BYE to Transferee. Is there any specific reason for
>doing this in the mentioned call flow.
>
>5.3.1  Target Busy
>
>              Transferor           Transferee             Transfer
>                   |                    |                  Target
>                   |                    |                    |
>                   |            INVITE  |                    |
>         Call-ID:1 |<-------------------|                    |
>                   |            200 OK  |                    |
>         Call-ID:1 |------------------->|                    |
>                   |            ACK     |                    |
>         Call-ID:1 |<-------------------|                    |
>                   |  INVITE (hold)     |                    |
>         Call-ID:1 |------------------->|                    |
>                   |  200 OK            |                    |
>         Call-ID:1 |<-------------------|                    |
>                   |  ACK               |                    |
>         Call-ID:1 |------------------->|                    |
>                   |  REFER             |                    |
>         Call-ID:2 |------------------->|                    |
>                   |  202 Accepted      |                    |
>         Call-ID:2 |<-------------------|                    |
>                   | NOTIFY (100 Trying)|                    |
>         Call-ID:2 |<-------------------|                    |
>                   |            200 OK  |                    |
>         Call-ID:2 |------------------->|                    |
>                   |                    |  INVITE            |
>         Call-ID:3 |                    |------------------->|
>                   |                    |  486 Busy Here     |
>         Call-ID:3 |                    |<-------------------|
>                   |                    |  ACK               |
>         Call-ID:3 |                    |------------------->|
>                   |    NOTIFY (503 Service Unavailable)     |
>                   | or NOTIFY (486 Busy Here)               |
>         Call-ID:2 |<-------------------|                    |
>                   |            200 OK  |                    |
>         Call-ID:2 |------------------->|                    |
>                   |  INVITE (unhold)   |                    |
>         Call-ID:1 |------------------->|                    |
>                   |  200 OK            |                    |
>         Call-ID:1 |<-------------------|                    |
>                   |  ACK               |                    |
>         Call-ID:1 |------------------->|                    |
>                   |  BYE               |                    |
>         Call-ID:1 |------------------->|                    |
>                   |  200 OK            |                    |
>         Call-ID:1 |<-------------------|                    |
>
>
>-Udit
>_______________________________________________
>Sip-implementors mailing list
>[email protected]
>http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
>
>
>
>


begin:vcard
fn:Nagesh Shekar
n:Shekar;Nagesh
org:Lucent Technologies;Anypath Messaging System
adr:;;7062 Polpis Road;Reynoldsburg;OH;43068;USA
email;internet:[EMAIL PROTECTED]
title:Consultant
tel;work:+1-614-367-5810
tel;fax:+1-775-248-3937
tel;home:+1-614-864-3983
tel;cell:+1-614-316-0094
url:htpp://www.lucent.com
version:2.1
end:vcard

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