tcrhelpforsms

I hadn't caught that you had responded in multiple locations.

If you see this as inventing problems, then it is clear you don't understand the use case.

Even ignoring the issue of carriers cracking down on SIM cloning, as you've said not all messages will be visible to all participants. So that makes it DOA.

You also clearly do not understand that the issues here are not all technical. Sure I could definitely bang out something using Twilio to send and recieve SMS, etc. Except Twilio requires you to comply with TCR. So again, that is DOA.

Sure if I was really adventurous I could buy tens (hundreds?) of thousands of dollars of telecom equipment and work on then have to negotiate peering with other providers. But you know, I figured I might ask on Hacker News as start.

I think you need to consider the user interface here.

Someone with the phone number A texts a message to number B. Say the message is forwarded to number C. In order for the user with device C to respond to A, it would first be necessary for B to rewrite the message text to say that the message came from A. They then the user of C needs to make sure to manually send the message to A. Now, depending on how savvy the user of A happens to be, they might not find it completely disorienting. If you were to attempt to send to both A and B via a group text that might help some. But then you'll also be getting extra copies of your messages fed back to you from B. Unless the forwarding on B is also smart enough to filter them. And then there is still the problem that in future conversations, the user of A might just send messages directly to C, bypassing the other forwarding recipients of B, defeating the point of having a shared point of contact.

So forwarding has considerable awkwardness and room for error.

Okay, as this has come up more than once, really what is needed is not just forwarding, but proxying. Is there actually software for Android that will do that?

That also looks quite intriguing as well. Though perhaps a bit more industrial than I might need, there is definite potential. I would need to investigate which have more friendly user interfaces. While I might be hip to using "AT commands" to "Send/receive batch SMS up to 300 characters", my wife would perhaps not find that amusing.

This actually looks quite promising! Thanks!

Forwarding is only half the requirements here though. Sending responses from a different number will generally lead to confusion, and further messages from the sender will not necessarily be shared. Though maybe if the sender is savvy enough with group texting it might work out okay.

Yeah, this isn't like e-mail headers where different hops in routing will insert additional information.

To clarify on "grandfathering": our use of the service predated our provider's involvement with TCR. Any new accounts created with the provider now requires you provide complete information on your business and its purpose to qualify for the product. As our account existed before that time, and they still wanted to take our money, they didn't cancel our account. Yet.

I suppose I should have been clearer, while I don't like spam, the issue is that TCR is about much more.

There was some discussion about dual SIM solutions with a cloned SIM in a different thread. But even ignoring the potential for incurring our carrier's wrath, with not all messages will be available to both parties, it doesn't meet the minimal functional requirements.

Yes, I should have perhaps more clearly stated that while the ostensible goal of TCR is reduce spam, it is at least as much about control and rent seeking.

I think that may have actually been the exact original motivating use case. That the bank kept trying to send 2FA codes. Though I recall that may not have worked at first as our provider was probably still classified as not being a valid destination.

I'd need to check, but I'm on team spaces and I think she is on team tabs.

Okay, that is a problem then. If both phones cannot see all messages, how would both parties have full context on the conversation? This would inevitably lead to both of us sending a response.

Okay, let me explain it a different way. Much like TCR is in principle supposed to be about blocking phone spam, wouldn't it just be a matter of time before cell providers start cracking down on cloned SIMs with the intention of preventing criminal activity? Whether you cloned the SIM for legitimate use or not.

I'll investigate this, but I'm kind of surprised this use case would be even allowed? How does this wind up being different than a SIM cloning attack?

I have not heard of such a thing in the US, but I will investigate.

So while that would work for calls, does that also behave as expected for SMS and MMS?