TL;DR: Go\Trunk is a middleman and isn't a provider and charges you more than higher tier SIP Providers, while routing you to low tier providers that could cause issues with your business.

We have been using Go\Trunk as our SIP Trunk provider for a while (~2-ish years) and we were actually pretty happy with them. But every month I decided to pick up the phone and make sure calls route properly. First i call my ISP provider knowing theyre on a VoIP service so its SIP to SIP to make sure that works and it did. Then i check just going to my cellphone. My personally cellphone (AT&T) wasn't ringing. So my first immediate thought was somehow, my AT&T Spam guard app blocked it. It didn't. Nothing there from the company number. So i called another employee, he didn't get a call. He also has AT&T but doesnt use the spam app. So i called another cell phone that wasn't an iPhone that was also AT&T...didn't go through. On my end, from the desktop phone it would ring, but the calls were not going through to the person i was calling.

We run FreePBX here so i went into a shell and checked the asterix logs and...no STIR/SHAKEN headers attached to the call after it hits Go\Trunk. Which obviously means AT&T is seeing our call is illegitimate and not even letting the call go through to the destination. We get a 200 back, but its fake. I guess its what AT&T does to make malicious callers think their calls are going through, but they aren't? I guess, I don't know that one. So i tried a number I knew that was a T-Mobile line, same thing. Tried calling someone i know who has Verizon, same thing. Now this is a problem because clearly its nothing on our end, its the providers end.

So I submit a support ticket to Go\Trunk and tell them what I just found and basically....what the heck?

The first response was "While they investigate, we have temporarily routed your US outbound calls through a different provider." A "different provider"? Are you not our "provider"? So i said back "Ok, well, what have you found so far that is the problem? Can i please have a more technical answer?" They replied back "I just switched your USA calls to another carrier provider and raised a ticket for the original carrier to investigate further." So their tech support doesn't even know what happened and the fact that our business line was "routed to another provider" was them telling me - "We are not a SIP Trunk Provider, were a middleman between the customer and low tier SIP Trunk providers."

Now, this might be common knowledge to some, but this was news to us and we used them for 2+ years and never had issues until we decided to do this test. NO WHERE on their website do they say this. That they, in essence, are infact, NOT a provider, but they will ROUTE you to a provider they probably have contracts with and clearly, we were moved, unknowingly, to another provider that did not put STIR/SHAKEN headers attached to our outbound calls, which is a red flag to telecom companies, and it drops the calls and (atleast the way AT&T does this), makes our PBX think the call was routed and we get a 200 OK, but its a lie to the phone system. So, this is just a warning to those that DON'T know this because I just caught them doing that, they do not disclaim on their website anywhere they are just a reseller to other providers, in fact they say "Go trunk is a world leading SIP Trunking solution." So they arent saying they are a provider, but they are saying they are a "solution" lol. They also say "Why GoTrunk? Because we set new standards in SIP Trunking!" Well, pretty low standards there.

We have ported our number to a higher tier provider that is infact a "provider", of course I won't say who just to keep to the rules in here as best as I can and its sad to know we were actually paying alot more, to get alot less. We were naive when we implemented having a PBX at the time, we hired better networking specialists, we audit ourselves better now, we have done our research, and its a mistake we won't make again.