3CX calls out on two lines simultaneously

[Halea]

Greetings:
I adjusted my outbound rules in such a way that if my SPA-3102 is already busy communicating over PSTN when another extension tries to dial out on the same PSTN line the second call gets serviced by my VOIP provider. (I have fixed flat rate on my PSTN and pay as you go on VOIP, so I try to send all my local calls to my PSTN first, if it is busy then I'm ok with sending it to VOIP). To that effect, I basically entered a second route for the outbound rule which handles my PSTN calls over SPA-3102.
This method works most of the time (4 out of 5), but occasionally it dials the same number over both channels. For instance, while there is no PSTN communications underway, I would call my cell, and I would get simultaneously two calls on my cell phone, one from the PSTN line and one from VOIP.
As this behaviour is rather uncertain, I turned the secondary route off for the time being.
Any ideas how to make this work in a stable fashion? :roll:
Thanks.
Halea.

 

[landfiets]

Maybe one of the lines is hanging after used. Can you try to see in the webgui or the logfiles if lines are hanging after being used? It would be logical then that it will say that it is allready in use.
How did you configure your outbound? Please make a picture of it or tell us exactly what you filled out. Did you do that in the 3CX system or in the Gateway. Because it would be best when the outboundrule is only in 3cx, otherwise it can conflict with eachother.