How to forward an external VOIP call on busy with 3CX? E.g. we have 3 VIOP lines, when the 1st is busy we want the external call to be forwarded to the next available line. My VIOP provider tells me this need to be done by our IP PBX software or VOIP box hardware. I have found the forward features/options for extensions but just can’t work it out for incoming external voip calls. Any advice is appreciated!!!