Mine is a small company with 2 incoming analog lines that we use for voice. One line rolls over to the other if the first is busy. I started using an */grandstream combo a while ago, and besides a couple of bugs that I have yet to work out (echo, ringing in the earpiece) its has been good for the company. I have been thinking that perhaps getting some digital voice channels, instead of analog lines, will help with the echo problem. It also seems like the next logical step in expanding to more lines. Can ISDN do this? I have heard that ISDN cannot do "hunting"; or I cannot have one number for multiple lines with 'ringdown'. Is that true? Is there something else that is preferable to just getting more analog lines? I think a T1 is a bit out of our price range at this point, but I don't know. How much is a T1 anyway? Thanks for any info, Sean R.