You can email them to enable receiving short codes for a specific number. That doesn't mean it works with all banks or whatever (the sending company may not allow Twilio numbers), but it does work for some of them.
The issue with SMS, in my limited understanding, is commercial numbers tend to come through shortcodes and shortcodes have their own set of delivery rules. Nothing of the sort from voice calls. I haven't had any instances of voice calls not coming through.
My (minimal) understanding of telecoms is the future is always a very long way away if you relying on complete rollout for usability.
Skimming that page, it also looks like possibly this is only replacing commercial long code users, not commercial short code users? But I didn't read carefully enough to be sure.
You would need to sign up for a voip provider and use the credentials they give you. Your app talks to this software using the web api, and this software will talk to your voip provider using SIP.
I don't know if Verizon would fit the bill, but the keyword to look for is "voip provider" (or "voip service provider"). As for protocols, I would start there if I were you: https://en.wikipedia.org/wiki/Voice_over_IP#Protocols
I'd love for something to be able to replace Google Voice for maybe $5 a month. Does anyone have any suggestions? Keep in mind that Google Voice offers "unlimited" SMS and MMS, and free calls anywhere in the US.
In the same space, but looking somehow more mature, and based on Freeswitch as its voice core: https://www.jambonz.org/ - it is available as a standalone project or a managed cloud (for small apps, a quick test, or prototyping).
My company is starting to use it. Dave is super helpful, and it handles SMS.
2. So I still can’t wrap my head around what happens when you go from a Twilio api call to the cell tower and ultimately the handset - @atonse
Some use-cases will require a VoIP Service Provider. Specifically, every time you send or receive a call from the telephone network (PSTN). Alternatively, you could use a SIP-to-GSM Gateway such as GoIP 8.
Fonoster will be particularly helpful when there is regional regulatory compliance or when a company wants to reduce reliance on traditional CPaaS Providers.
Note: A VoIP provider is not needed for internal calling (like an office setup) or browser calling.
3. Would Verizon give me an IP to connect to? Which protocol?
Most telephony providers have SIP interconnection of some sort but are usually for big customers or to communicate with lower-tier providers.
But as @bzxcvbn pointed out, you can find a local VoIP Provider relatively easily. I use a few for testing, like DIDLogic, CallCentric, and VoIP MS.
I'm glad there is work on open alternatives to twilio, but I want to either confirm some features are missing or find out where to learn more about them.
I have a call center. We call consumers who signed up on our site, put them in a conference room, and then if they're interested we transfer their call over to a client who pays for the warm transfer. Additionally we receive incoming calls which we need to put into a hold queue and pull from.
Is anyone aware of a similar open source project for text messaging? And, would I use the same voip provider gateway?