I had a terrible experience with these guys and dumped them as soon as I could.

During the port-in phase, they gave me a 20 minute notice on the FOC. When I contacted them to have it postponed, they told me there would be a charge for that. Before I could reply, they ported the numbers. Needless to say, we weren't ready and my new customer was without service for several hours.

Their systems calculated CDR incorrectly leading their bots to think that I had exhausted my available funds. They turned my service down and it took a while to get it back up. During this time, they were arguing with me that it was my fault. When I explained, his response was "I guess we're just not a good carrier for a guy running FreePBX in his basement.

Kelvin is hot-headed and foul-mouthed; every other work out of his mouth was the F word. I could write volumes about our other experiences, but this should be enough to warn you off. I ran across some other people on Reddit who had similar experiences.

I have all the email threads to back this up; it was actually worse than I portrayed here!
Hi Scott-

I use V1VoIP and Alcazar. You can read my post in this forum regarding Alcazar. MagicTelecom is another one.

You can go with other, larger companies if you want that comfort level. Examples of those would be voip.ms, broadvox, and many others that folks here can probably give testimonials for. At one point I used Verizon and their service was excellent. My chief complaints with them were as follows:

They are a legacy LEC and everything moves at glacial speeds
Their paperwork requirements are massive
Their online systems are antiquated

A positive feature was on LNP, they had a dial-up number where you could, on the FOC date, call in and have the numbers ported immediately. The window to do that was open all day on the FOC date.