We have an older Telrad system at our main location which has an AIP 30 card which connects over a T1 to our remote site which has a Helix 20 Gateway system. Currently we are limited to 16 Avanti phones and I would like to increase the phones to about 20. We've had the Helix system for over 3 years and it has worked very well. What's the best way to increase the number of phones at the remote site? We also have an older VM system which (from other posts) I believe could be upgraded using an IPEX card. Would the IPEX card give us any additional options for VoIP? Thanks.