Progress on the GSM network at FreeCalypso HQ

Denver Gingerich denver at ossguy.com
Tue May 10 22:35:36 UTC 2022


On Tue, May 10, 2022 at 02:09:30PM -0800, Mychaela Falconia wrote:
> > You could try https://jmp.chat/ if you care about texting features
> > (while calls use Jabber/XMPP by default, SIP is supported too).
> >
> > If you don't care about texting, then the cheapest numbers you will find
> > are at https://bulkvs.com/ .
> 
> The way you worded it, are you saying that BulkVS does not support
> SMS?  Their documentation says that they do support it - are there
> some big problems/gotchas with BulkVS SMS service that I need to be
> aware of?

I'm not aware of any particular gotchas with the BulkVS SMS service, though I have not used their SMS service myself.  It is perhaps more expensive than other providers (as an example, many bulk providers do not charge for incoming SMS), but otherwise seems fine on the surface.

My comment about "if you care about texting features" referred more to some extras on top of SMS that I recall you were not a fan of from your previous posts here (more on that below).  If one is concerned about group texting, for example, then BulkVS probably won't suffice.

Having tested a lot of different VoIP providers claiming to support SMS, I would just caution anyone using a new service to test for the full set of ASCII characters and ideally some non-ASCII UTF-8 if you care about such things, since many providers will silently ignore and/or convert to spaces any characters that aren't in the GSM 7-bit default alphabet (per https://en.wikipedia.org/wiki/GSM_03.38 ) rather than upgrading to UCS-2.  Perhaps also test deliverability over time.  And be especially careful about whether the provider supports P2P routes or only A2P - it is hard to find the former, and very expensive to use the former (not to mention likely inappropriate if you're not a business sending transactional messages).

> At first glance BulkVS looks like a much more attractive service, not
> just in terms of price, but also in terms of target audience - I am
> NOT looking for a service marketed directly to end users, instead I am
> looking for a backhaul/back-end service whose customers are then
> providing services to end users.  Basically Themyscira Wireless,
> acting as a very small cellular carrier, will be buying phone numbers
> and PSTN connectivity service in bulk from a suitable back-end provider,
> and ThemWi will then provide cellular (GSM) service to end users.  To
> an end user though, the service from ThemWi needs to look and feel no
> different from "regular" service from a traditional carrier like
> T-Mobile - when an end user gets a service with a SIM card from ThemWi,
> she needs to be able to call and text whomever, and receive calls and
> texts from whomever.  Are you aware of any problems with BulkVS that
> would make this idea not work if I choose BulkVS as the back-end
> provider for ThemWi?

The main issue I would caution you about here is this one:

  https://wiki.soprani.ca/FAQ/Why%20isn%27t%20my%20number%20being%20accepted%20by%20an%20online%20service%3F

You will run into the same issue with any VoIP provider, since their numbers as classified as type "voip" instead of type "mobile" (though of course these services could switch to (or may already be) banning by carrier instead of number of type).

I don't know of a way around this yet.  Let me know if you find one.

> There will be just one key difference between traditional carriers
> and ThemWi in terms of end user services: I am fiercely against MMS,
> and the only thing I want to do with it is block it.  Thus "texting"
> in my world means SMS and not MMS.

Understood - I have read your previous thoughts on this and they make sense.  Sadly, I don't think "blocking" is possible.  Rather, senders' MMS will just silently fail to get to you.

I suppose you could write a bot that replies to MMS with an SMS that says "this number does not support MMS" but that's probably the best you could do.

> I also don't relish the idea of adding Jabber as one more required
> piece to the puzzle, which appears to be required at least for SMS
> with your JMP service.

Right, that's reasonable as well.  I think BulkVS will do SMS over SIP (via SIP MESSAGE), but haven't confirmed for sure.

Denver
https://jmp.chat/


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