When I was a kid I remember discovering the heft of the home phone came from a big chunk of metal screwed into the plastic case.

(My family moved to cell phones so I got the opportunity to disassemble the old phone.)

Maybe just find some washers and glue them inside your handset and receiver?

Do you have an ATA you like? They are all janky in different ways in my experience.

Janky is directly proportional to cost. Grandstream are the jankiest and least expensive. I like the Cisco 191; it is a fine unit but costs about $100-120.

Oh nice! I have been working on my own too! (https://havenphone.com). I was planning on the exact same model and pricing as well.

I am curious: have you gone down the tr069 rabbit hole? If not how do you plan to do endpoint management?

Are you using a Fanvil H2W? Too? That was my first phone choice.

I also learned of https://www.beanstalk.club from this thread as well. Looks like there are a few folks trying to do similar services without the proprietary hardware and waitlists.

FYI - your support email at havenphone.com is bouncing back as not found.

I’ll send you a message to your support account :-)

thanks! of course that email was misconfigured for a few hours. fixed now!

The main feature I want for my kids is an explicit allow list to keep them from gettin spam or talking to randoms.

The manual I found doesn't seem to have this feature. Also the advertising page has "Cloud Apps for news, weather, and more" :( https://www.hmd.com/en_int/nokia-3210?sku=1GF025CPD4L02

Yes you should check KaiOS phones for that.

Now the problem is that they're not "dumb" enough as they have a web browser, youtube etc, but that can be considered fine because the experience for those is so bad that it's unlikely to get addicting.

How about a PinePhone with DeltaChat?

Have you found a under powered phone that lets you lock down the Phone's incoming to an allow list?

That is the thing me (and most parent friends) want: freedom from spam calls and potential strangers.

It blows my mind that the current Cisco ATA is $150+.

For the service I am building (havenphone.com) I used Grandstream HT801 with success with voip.ms. I don't love how easy their cloud can take over the device though.

There are much older ATAs on eBay for ~$20, they still work fine, since POTS and SIP don't change

What tech stack did you use before? It is interesting so many comments mention Pi when there are so many boring VOIP phones.

I wrote an app that some friends use right now. So, always interested to hear what people cobbled together!

I went the DIY route (you can find the details as a parent comment). But, I had good luck with voip.ms as a SIP provider. It is inexpensive at $1.10/month for the phone number and $0.008/min for calling. And it has a pretty good history of user forums, wiki, etc for debugging hints with various hardware.

What price point would feel good to you?

I am working on a similar service for my own needs (and some other friends). But, my current plan is to hit $100/yr or so but the hardware is included in that cost. I am assuming $2/mo for costs of the number and minutes and retail costs for VOIP hotel phones is about $50. Hopefully the hardware costs amortize out and then I can offer a discount to users on subsequent years.

(If you want to go DIY you can save quite a bit of money too- I provided some breadcrumbs for doing that in my comment on the parent)

I made something using a VOIP phone and voip.ms. What provider has a $5/mo kids cell subscription!?

voip.ms is about $1.30/mo with the cost of the phone number (DID) and "minutes".

I have some more breadcrumbs on this thread if you are interested in details on my setup too.

Regarding minutes, how many minutes? My kids basically hog my VoIP "landline" talking to their cousins 50% of the time they're home. (They're actually playing games together and using the phone as voice chat). I've been thinking of trying to get a second line for them to hog but didn't want anything with limited minutes.

It is pay as you go $0.008/min

https://voip.ms/pricing

My cellphone provider offers a limited kids cell subscription. Things like "can only call 5 different pre-approved numbers, no data traffic". I think the business model is that after a period of time, people bump into the limitations and upgrade to the $10/mo version.