I don't know if One-X Attendant is available anymore now that Equinox Attendant is the 'new' thing. I'm not a fan. One-X Attendant and IPOCC is originally from Tenovis and what Avaya's done, as far as I can tell, is make the IPOCC ACD application a "Breeze plugin" and your Equinox Attendants can't operate standalone and must connect to the Equinox Attendant Breeze plugin.
One-X Attendant had a client/server architecture too, but if you had just 1, you could have the client/server software on the 1 PC. Now, I think they're trying to force your hand into putting a receptionist ACD server in.