Hello, I'm trying to migrate our company to a new PBX and was wondering if 3CX would work well for us. Here's what I'm looking at: We use VVX 410s everywhere. We have probably 400 of them at this point and I don't think I'll get approval to replace them in a new system. I see 3CX supports them as "Legacy" but I'm not sure what that means. I don't know what No PnP support means - I get it is plug and play but what does that mean? I have to manually log into each phone and provision it? No STUN support - does that mean I can't provision a VVX phone internally and then give it to a user to use outside of my network? Or that STUN specifically will not work for that and there is another method? Or are we talking major NAT issues as a result of no STUN? No SBC Support - Does this mean I can't do site-to-site calls through our network? What if there is a VPN at each site? I'm guessing then it will traverse network OK. What if there is a 3CX server on each side of the VPN? What about extension dialing at those two sites? Will that work? No Full CTI Support - I get this one but as long as soft phone works OK I don't care too much about CTI unless I'm underestimating its usefulness Manual DST support - does this mean manually changing your phones time each time DST hits? Or just setting it via a setting in the phone manually? Can it just like to an NTP server still? SBC Selection We have a number of Sonus SBC1000 and 2000s. I see these aren't a supported option but will they still work and what are the possible downsides of using one? In the end they are just transcoding the same codecs and passing SIP/PRI Traffic. AD integration Can users log into the smart phone with AD credentials or is it always via the template file they get emailed? I suppose the latter may actually be easier but was curious to what degree a user can use their Active Directory identity in 3CX Mobile integration The app store reviews for 3cx app are pretty bad but most apps have bad reviews for enterprise stuff. Is it better than the reviews state? AutoAttendants/Hunt Groups How complex can I go with hunt groups? Can I get full reporting on calls? What about Auto Attendants at a single site and possibly transferring to other auto attendants on other 3CX systems connected by VPN? Is this possible? Troubleshooting/Support What does premium support look like with 3CX in the event of a major outage? I haven't found any SLAs anywhere but phones are pretty important in most of our offices. How easy is it to gather SIP logs, call quality reports, device, and user statistics in 3CX GUI?