This question is directed to those who have used both Twilio and other elastic SIP trunk providers within the last year:
I switched some analog POTS lines away from my RBOC to Twilio about 3 months ago because of the huge cost savings in my own use case. Setting it up for outbound calls was extremely easy, and incoming calls seemed easy as well. However, I noticed as many as 40% of incoming calls were 401 unauthorized on the first attempt, but on the second the call was connected with no problems. After going round and round with support from both the Twilio and FPBX communities, I think I’ve eliminated the majority of the inbound call failures. It’s too early to tell if all have been eliminated, but it appears that the percentage has dropped significantly.
I have other lines at other sites that I want to move as well, each with their own FPBX installation. However, the issues with Twilio have made me nervous about moving to them, and I’m wondering if you would recommend a different provider like Telnyx or Voip.ms due to the reasons cited above.
For the record, I think that if I created a fresh FPBX installation and added Twilio as my only trunks that it might not have been so bad, but reconfiguring an installation that was configured with other trunks previously may have been a large part of the problem.