Current Thinking for Whole House Paging

upstatemike said:
How many phones can you place into a group when all of them are set to auto-answer?
I've never run into a limit, but I'm also just using it in a normal residence. I think at max we only use about a half dozen extensions because I don't need to use every phone even in a "intercom all" situation. For example our most common use is to announce dinner time from the kitchen phone and that intercom group doesn't include the den phone because it is literally four feet away from the kitchen phone. However, I have never experienced any issues and would think you could use at least a dozen or more extensions without issue.

I could see more of an issue if it was a large business and you needed to send an emergency broadcast out to a much large number of phones. I have read that for those situations you can use the WebRTC protocol because it is much lighter and you can send it out to very large groups at one time. I haven't personally looked into it however because I've never had a problem using the normal intercom and auto pickup feature in my house.

Edit - I should note that any limit placed on the number of extensions is going to be a result of computer power, not a software limitation. I'm running a virtual machine with pretty limited resources and still don't have any issues. I don't think anyone using it even in a large residential or small business setting would experience any limitations either. If you want to try it with 100 or 500 extensions, that may be a different story however.
I am currently paging to 22 Panasonic phones (I guess 21 if you subtract the phone that is doing the paging) plus an amp feeding speakers in an additional six locations. I would love a system large enough to cover the speaker locations with phones and allow hands free response to an all page. I was never able to do more extensions with a larger Panasonic PBX because the larger systems remove some key features I depend on such as distinctive ring sound by CO line (so I can decide if I'm going to pick up without having to go look at which line is ringing) and automatic barge-in so any phone can pick up a CO line already in use and join the call without entering a code or any other extra steps. Maybe Asterisk or Grandstream would be the answer. I just wonder how reliable a LAN based system would be with all the traffic from streaming and video cameras I have going on?
That is one option. I am weighing that against simply reducing the number of items on my LAN and go with more hard wired ( as in serial and analog, not just wired Ethernet) solutions for music etc.
 I currently have 25 Sonos Zone players, 14 Sonos controllers, and 14 Amazon Echos. I'm guessing I can find a less network intensive way to do music. If I do cut back then I'm not sure I want to undo what I've gained by adding 30+ SIP phones.
Wait how many What?! Holy smokes I thought I had a lot of devices! FYI I bought a Yamaha RS202 and paired it via bluetooth to the echo dot and it seems much better than a sonos!
Feature works great. Wife says it's "Creepy"  hearing my disembodied voice broadcasting throughout the house.
I'm sure it'll show up - but it may take a year or two.  We've recently started doing Echo Dots in the kids' rooms... only annoying thing is they're on separate accounts so I had to fake it with a burner cell phone and an SMS-enabled SIP phone number to get it to enable the drop-in features since it won't enable that feature until you've tied it to a phone number.  The whole reason I do all this is so each kid has a separate spotify account from our family plan.
Those Panasonic systems bring back memories... I just literally sent two of the KXTD24's to recycling within the last year.
Within the next year I'll be in the same position as you... we're expanding to a newer and bigger house.  I have two Grandstream UCM6510's on the shelf so I plan to use one of those to see how close I can get to the old PBX style features.
The one thing I'm not sure how you'd tackle is the muting of other devices.  Even with Alexa you're not getting that - unless of course it's the Echo that would be muted, then I guess it kinda happens automatically.  Otherwise I think you'd have to monitor call activity events to know what's going on in the room.  Definitely not as simple as the old off-hook detection.
I agree the echo dots need accounts within a family or something. Its quite a challenge to use them as intercoms. We have the onq selective cal intercom. We used it and liked it when the kids were babies for monitoring their rooms like baby monitors. No other system was comparable and offered this feature. Problem is Ive changed my hubs three different times because of some failure and after the last hurricane both door calling stations cameras no longer work!
I've been seriously considering a big RTI installation in my next house.  It's a little pricey, but their handheld remotes and their in-wall touchscreens are finally getting the intercom features working.  You can also use their flagship remote to do video intercom which is pretty unique.  This is based on SIP so it'll interop with a DoorBird Doorbell cam and any other 3rd party SIP video devices.  SIP has its limitations, especially if you likes how the old key PBX systems worked, but there are workarounds for most things.  I'm actually pretty anxious to get going on our next house!
Lots of good input but I'm still not sure what I would do if I had to change my current system. I think my best option is to step back and review my requirements and see what fits rather than looking at different products and try to see how they could be made to work. I don't think one product is going to cover everything.
These are my MUST HAVE requirements:
  Simple whole house announcements from anywhere in the house to everywhere in the house. Must mute any music playing to enable the announcement to be heard.
  Don't really use room to room conversations much but do need to drop in and monitor areas sometimes. Door intercom is probably only instance where 2 way conversation is needed.
  Don't care if this happens via Paging System, Whole House Music System, or Phone System but must have announcements for incoming caller ID, vehicle in driveway, which doorbell is activated, mail delivery, motion in garage, etc. These announcements need to mute any music playing to ensure they are heard.
  Must support multiple lines and provide speakerphones at all locations
  Must have indication when phone lines are in use and at least one display in some location to monitor when extensions are left off hook.
  Must have some kind of voicemail with an indicator at all locations when there are messages waiting
  Must have a way to interface to other systems. Must automatically mute music in the room where a phone is in use (and only in that room. Muting must not affect music in other rooms)
  Must support at least 24 phones in fixed locations. Do not want anything that can wander and not be where it is needed. Do not want anything that needs to be charged or can otherwise get into a state where it is not instantly available for use in an emergency.
Im on my phone and dont recall the entire thread but did you consider nucleus? I bought a couple in an effort to replace my legrand onq intercom but wasnt compelled enough to really install them.
I think my Echo Shows currently have more features than Nucleus offers and they're cheaper. I don't think either company supports paging announcements unless Nucleus has recently added this?