Hello: I have a Total Control chasis with a Hiper DSP T1 NAC but working with a E1 line, becouse it has a "daughter card" that gives de 6 extra modems for a E1 line.. it is working fine... Besides the Total Control have 1 Hiper DSP NIC T1/E1, 1 Hiper Router Access Card and the AC PSI 130A card.. It all working very good. Can I add to that Total Control a USR TOTAL CONTROL DUAL PRI NAC/NIC Set E-1 without any problem..? Is it compatible with my equipment..? Do not I need anything else to add to my TC other E1 leased line..? Someone told me that I will need some digital modems for this card to works... What he will referred with digital modems..? Thanks in advance Roberto Ravetti Intercom I.S.P Rio Tercero - Cordoba Argentina