Active job

VoIP Intercom (SIP) for two gates

I've been in discussion with a gate company about front yard fence with one pedestrian gate and one driveway sliding gate. Unfortunately, things are not progressing on the intercom front, since I can't get information about intercom products they use, but I was told that one of would be GSM, meaning I'd have to pay for a monthly contract whether I get anyone at the door or not, and the other one WIFI, which means if I don't have data enabled on my phone all the time, there is no way to reach me. I am looking for the intercom person/people who could do everything I am looking for, and then I can go back to the fence company and tell them to just make the fence, gates and gate automation, and co-ordinate with intercom people. Even though it sounds more complex, it shouldn't be as it seems fencing people use subcontractors for gate automation and intercoms anyway, which is probably why I can't get the information about details of the intercom they're proposing. The intercom system I am looking for needs to control both gates independently, meaning I don't want both to be opened at the same time, but to be able to open each one individually as need arises. The intercom needs to be able to withstand NZ sun and rain, as it will be installed on one of the gate's pillars. It should have a keypad where I can use local codes to open the gates in case internet is down. It should also have a capability to call the number assigned to the intercom from my mobile and use dtmf remote code to open the gates. To achieve this functionality of calling my mobile, I am planning to use 2talk cloud pbx. This way I'd be paying only if someone calls from the intercom and I answer, rather than having to have a mobile prepay plan all the time. Ideally the system would allow for more than one local code per gate, so that I could give one to the tradies if work needs to be done while I am not around, another one to a guest etc. Another reason I am looking at SIP intercoms is that I can then manage them myself rather than having to be stuck with some online service/app to buy new 'keys' or having to call out installer every time a change needs to be made. Also, at present I may not need a video monitor in the house, but once the renovations start, I will probably consider having it and will wire accordingly. SIP looks like a thing that would allow me to do this in a staged way without too much trouble. In terms of the intercom devices, I researched Fanvil, but the only thing I am not sure is handling of two gates with device like i31s or i23. I focused here only on the intercom and gate opening aspect as this is very important to me, but if you do gate automation as well, then we can also talk about this too. What I see there seems to be specialisations in one or the other, which seems strange as gate motor ends up being controlled by the intercom, so that all the electrical and data work can done by one person/company, to avoid any interoperability and warranty issues. That's why I didn't go down the route of buying intercom myself and then trying to integrate it to whatever solution fencing company ends up installing, as I want to be able to call someone knowleadgable if things stop working, within the warranty period and afterwards. Fences don't break, but motors and electronic devices do, so I need a peace of mind there.