In short#
I only answer calls that arrive on the EVA number of your workspace. In 3CX, the job is therefore to send the calls your ring group or your queue does not pick up to that number. That is call forwarding: 3CX places a new call to the EVA number, before I answer.
Depending on your version, the screen may say forward or transfer to an outside number. Either label means the forwarding to EVA described here. A call transfer is something else: that is me handing a live caller to a human colleague during a conversation that already started.
Two settings are enough: the destination for unanswered calls, and an outbound rule that lets the call reach the EVA number. The second one costs the most time.
Copy the EVA number#
Open Settings → Telephone → Lines.
Find the line your callers should reach.
Copy its EVA number in international format, without spaces, for example
+32470000000.
Keep that number at hand. You will paste it twice in 3CX: once as a destination, once in the outbound rule.
If you want the general principle first, or another phone system, see Forward your calls to EVA.
Ring group or queue#
In the 3CX admin console (v20), open Admin → Call Handling, then add or edit the ring group or the queue your calls go through. Labels move between versions, but the two settings I care about stay the same.
Look at the ring duration first, Ring Time. That is how long members ring before the call counts as unanswered. A ring group often sits at 20 seconds, a queue member cycle at 30 seconds.
In the destinations for unanswered calls, choose Mobile or External Number and paste the EVA number in international format, without spaces.
Do it for every period you want covered: office hours, out of office, break, holidays. A period left empty sends me nothing.
Save, call your public number and let it ring without picking up. If I answer after the ring duration, forwarding works.
Outbound rules#
If the call simply dies at the end of the ring, this is almost always the reason. The overflow call is not placed by a user: 3CX places it with a system extension, the one of the ring group or the queue. An outbound rule restricted to calls from extensions or from extension groups therefore never fires.
Create or adapt a rule that recognises the destination instead of the caller.
Base the rule on the prefix of the EVA number, on its length, or on both.
Do not restrict it to a list of extensions, or include the system extension of the group or the queue explicitly.
Place that rule above your blocking rules. The first matching rule wins.
Check that the trunk used by that rule accepts calls to the range of the EVA number.
Pitfalls#
Multi Company mode. In that mode, the destination if no answer may omit forwarding to an outside number by design. Workaround: set the destination to a user or an extension whose own forwarding rules send to the EVA number.
SIP trunk voicemail. If your provider voicemail timeout is shorter than your Ring Time, the provider kills the call before 3CX can hand it to me. Shorten the ring duration, or ask the provider to raise or disable that timeout.
Number format. International, no spaces, no parentheses. A number written in national format is often refused without warning.
Going further#
3CX documentation: call centre and queues
Call forwarding in general, across phone systems: Forward your calls to EVA