Summary:	ASTERISK-30191: core/ari/pjsip: Add refer mechanism to refer endpoints to some resource
Reporter:	Maximilian Fridrich (mfridrich)	Labels:
Date Opened:	2022-08-25 02:21:34	Date Closed:
Priority:	Minor	Regression?	No
Status:	In Progress/In Progress	Components:	Applications/NewFeature Core/NewFeature Core/Stasis
Versions:	16.28.0 18.14.0 19.6.0	Frequency of Occurrence
Related Issues:
Environment:		Attachments:
Description:	Currently, Asterisk can refer endpoints to some resource or URI only during a call using the Transfer application. However, there are use cases which require out-of-dialog refers for click to dial or remote dial scenarios. For the PJSIP technology for example, out-of-dialog REFERs provide this functionality, and this scenario is described in RFC 5359, [section 2.18|https://www.rfc-editor.org/rfc/rfc5359.html#section-2.18]. A new ARI resource for endpoints (possibly {{/endpoints/refer}} with similar parameters to the sendMessage endpoint) could provide this feature. Note: I am already working on this feature, so please feel free to assign the issue to me.
Comments:	By: Asterisk Team (asteriskteam) 2022-08-25 02:21:37.890-0500 Thanks for creating a report! The issue has entered the triage process. That means the issue will wait in this status until a Bug Marshal has an opportunity to review the issue. Once the issue has been reviewed you will receive comments regarding the next steps towards resolution. Please note that log messages and other files should not be sent to the Sangoma Asterisk Team unless explicitly asked for. All files should be placed on this issue in a sanitized fashion as needed. A good first step is for you to review the [Asterisk Issue Guidelines|https://wiki.asterisk.org/wiki/display/AST/Asterisk+Issue+Guidelines] if you haven't already. The guidelines detail what is expected from an Asterisk issue report. Then, if you are submitting a patch, please review the [Patch Contribution Process|https://wiki.asterisk.org/wiki/display/AST/Patch+Contribution+Process]. Please note that once your issue enters an open state it has been accepted. As Asterisk is an open source project there is no guarantee or timeframe on when your issue will be looked into. If you need expedient resolution you will need to find and pay a suitable developer. Asking for an update on your issue will not yield any progress on it and will not result in a response. All updates are posted to the issue when they occur. Please note that by submitting data, code, or documentation to Sangoma through JIRA, you accept the Terms of Use present at [https://www.asterisk.org/terms-of-use/|https://www.asterisk.org/terms-of-use/]. By: Maximilian Fridrich (mfridrich) 2022-08-25 02:23:20.104-0500 I have started implementing this feature and I have run into some design considerations that I wanted to clarify with the maintainers before I continue. I am interested in implementing this feature for the PJSIP technology, and I am not aware of any other technology that provides this feature. So my question is how general this feature should be. Should I create a functionality in the core to allow refers for any technology? (I would mirror what message.c, ast_msg_tech, etc. provide.) Or should I make the endpoints API resource depend on res_stasis_refer which in turn uses res_pjsip to send refers? The first option would allow this feature to be implemented for other (future) technologies as well. However it does touch the Asterisk core. Whereas the second option works with external modules and does not touch the core, however it is more difficult to extend in the future. Please let me know what you think would be the better way to implement this. By: Maximilian Fridrich (mfridrich) 2022-08-25 06:21:51.488-0500 Actually, I think I have to go through the core. I'm not sure if there is another way to cleanly go from ARI logic (which must stay independent from technology specifics) to technology specific logic. Especially since both the ARI endpoint and the application must share the refer logic. By: Joshua C. Colp (jcolp) 2022-08-26 06:40:48.285-0500 The issue tracker isn't really the best place for discussions like this as unless people actively monitor all the issue traffic going on they won't participate. The asterisk-dev mailing list[1] goes to a wider audience and is where discussion occurs. [1] http://lists.digium.com/mailman/listinfo/asterisk-dev