Set up system, everything running well. Need to decide how to set up the PSTN lines. We had 10 PSTN lines with 10 people. Current system all VOIP, which runs well but the principals still want PSTN for their calls. I want to reduce PSTN to about 5 lines. Ordered Grandstream 4108. What is the best way to set up the incoming PSTN or VOIP? In the old system the incoming line was PSTN and transfers to the extention requested and stays locked. Next call come in and phone company rolls busy 1st line to second line, it transfers to extention and locks and so on. I suggested VOIP on the main number because with 10 channels, we only need 1 number, but then don't we have the VOIP line on the transfer? Principals are afraid the quality will be bad. Can we have it set up so that the transfer goes to a PSTN line, like an inbound rule? Thanks in advance.