We got 3CX 10 small business edition, fully up to date, with 6 PSTN lines. We can do 8 simultaneous calls and use all 6 PSTN lines EXCEPT we cannot have more than 4 simultaneous outbound PSTN calls. The call drops as soon as it dials. I ruled out the 4-call limit for G.729 because that codec is the 4th in priority for all extensions. Any ideas?