This is not straightforward but would be possible with a Call Flow Designer (CFD) application. All inbound calls (that you want to route to the previous extension) would need to go through this CFD. In addition, you would need to read the Call Detail Record (CDR) files 3CX can optionally create to see who answered the call previously, then have the CFD forward the call to that extension, or a default extension.
There are some additional considerations, however. For example, do you want to transfer callers to an extension that is currently on the phone, or their presence is set to something other than "Available", or perhaps the phone is not even registered (phone is turned off, or extension has been deleted). Further, how far back do you want to go to determine where to forward the call, if the caller has not called for over a year? And if the extension is not available, where do you want to forward the call?
To accomplish this task you are going to need some custom code, and/or leverage existing add-on tools. First, you need to read the CDR records into a database the CFD can query. Our
3CX Exporter tool can automate that process. Then you need to write a CFD application that can query the database and make routing decisions based on agent availability. You may want to look at our
3CX Call Router which can route calls by looking up values in a database, but ultimately I think some additional code is going to be necessary to complete all the requirements.
