Hello Freeswitch Team,

I am new to freeswitch and trying to figure out if Freeswitch support RFC 4579 adding new member to conference by REFER.

Question:

Will Freeswitch support adding a member to conference by means of REFER message as mentioned in RFC 4579 section 5.5 (https://tools.ietf.org/html/rfc4579 ) ?

What all I tried so far:

I tried the exercise given in confluence dial-plan way to add a member to conference but it works through DTMF trigger. I am looking for something SIP based resource add to conference.

I see that Freeswitch documentation says It supports RFC 4579, But will it support adding member to conference by REFER messages(5.5 section in RFC 4579) ?

I saw many Tickets around this area but nothing clearly answers my question. Few example links:

https://freeswitch.org/jira/browse/FS-7259

https://freeswitch.org/jira/si/jira.issueviews:issue-html/FS-5611/FS-5611.html

https://lists.freeswitch.org/pipermail/freeswitch-users/2016-August/121795.html

Scenario I tried :

When I try to REFER a member to conference, Freeswitch trigger the outbound call but it treats it as blind transfer and kicks out the party which sends refer message.

I want freeswitch just to include the referred member but not kick out the party which sent refer. and be in conference call.

====================================================================================================

There are 2 members in conference. one member is dialed through gw. that member is trying to add another client which is sip:service@172.29.0.3.

Freeswitch triggers the Invite to Refer-To member but it sends BYE to Referred-By member. Treating it as a blind transfer.

====================================================================================================

REFER sip:gw+sbc@172.29.0.2:5060 SIP/2.0
Via: SIP/2.0/TCP 172.29.0.3:5060;branch=z9hG4bK-34-1-5
Max-Forwards: 70
To: <sip:gw+sbc@172.29.0.2:5060>;tag=mB6pSrNNZ4Sta
From: sut <sip:service@172.29.0.3:5060>;tag=34SIPpTag011
Call-ID: 0ce57982-42a7-1238-c39e-0242ac1d0002
CSeq: 8859010 REFER
Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, NOTIFY
Supported: replaces
Refer-To: <sip:service@172.29.0.3:5080;transport=TCP>
Referred-By: <sip:172.29.0.3:5060>
Contact: <sip:172.29.0.3:5060;transport=TCP>
Content-Length: 0

Is it possible in freeswitch ?

Thanks,

Geeta