As other commenters have pointed out, there are alternatives to using Sangoma’s SIP trunks to send and receive texts. There are also alternatives to using FreePBX that have very robust SMS texting included - and they handle all of the regulatory issues at their end. Take a look at https://www.getweave.com/. But be prepared for some sticker shock if you are using FreePBX on the basis of primarily cost.
I primarily steer clients toward a complete Sangoma solution (hosted FreePBX, Sangoma SIP Trunks and Sangoma Connect for SMS messaging) - it’s just the most straightforward to manage this way and the support from the Community is by far better than other systems, including those like 3CX (which also has integrated SMS as well as a decent softphone). 3CX supports texting on flowroute trunks. How to enable SMS Text in 3CX. Manage them all from the chat feature
At my own office, which has been using FreePBX since 2004, we used to have SMS texting on the Vitelity trunks and DID’s (they have a portal web app for this, similar to their Fax web app) But we’ve since migrated our vitelity trunks to flowroute. All the sip trunk providers I am aware of these days though do require 10DLC registration, but it’s pretty much a one-time PITA and really not that difficult. we didn’t have any issues registering two of our number (our support numbers) through flowroute. In fact, flowroute sent us alerts well in advance that it was required.
All that said, It frankly would not be all that difficult for Sangoma to incorporate SMS into Sangoma connect through major SIP trunking providers like Flowroute. I have a “feeling” it’s a revenue capture issue though. Unless Sangoma can capture revenue from the integration of other SMS enabled Sip trunk providers (like 3CX does), it’s not going to happen because it can take revenue away from other Sangoma products. As for FreePBX being OSS, Sangoma in fact sells a “commercial” version of FreePBX called PBXact, and FreePBX is more “freemium” than “OSS” these days. Try setting up a robust business class FreePBX system without buying many other add-on “commercial” modules. So the argument against 3CX being proprietary really is somewhat of a red herring.
BTW, like waldrondigital at my own office I use textable for sms and mms messaging with two of my flowroute numbers that I ported over from Vitelity. It requires keeping a separate Web app open on the desktop, but since we do not use Sangoma connect internally, That’s just fine. We use 3CX softphones on the workstations anyway (very usable softphones with video capability and they do not require a 3CX server and work with FreePBX - and they are “free”), and Asternic’s FOP2, as well as Asternic’s CDR Reports and Asternic’s Call Center Stats, (all three far superior to the “equivalent” Sangoma commercial modules IMO).