We have a Yeastar S20 unit and I also have a legacy Tadiran PBX...I was wondering if anyone knew of a way that I could use the Yeastar as a standalone vmail system with my legacy PBX? I have 4 analog ports on the Yeastar but how do I pass the call info to the Yeastar and access the correct boxes and also can I light the lights on Tadiran from Yeastar unit? Is there a dial string that I can use once on the Yeastar to access a particular vmail box? I could forward the call from a non answered Tadiran extension to a speed dial number that has the Yeastar group and then put out the correct string for whatever extension was forwarded...hope this makes sense...if I can't light a MW light then I can send message to email...thanks in advance for your response. If this works I can sell theses as vmail systems on almost any PBX.