I'm not really old enough to have experienced Centrex, but for small businesses its promises makes sense from a business point of view. Less maintenance/support overhead is a huge plus.
sounds good. until you run conferencing services or whatever. Then the pricing is pretty simple: buying wholesale SIP and operating on your own is substantially cheaper.
irl maintenance is pretty straightforward. I do it as a side thing to my main job.
Somewhat off-topic, but what wholesale SIP provider would you recommend? Looking for something small-scale for now, pay as you go as opposed to $X,000/month.
Nexmo is quite good.
We are wholesale SIP provider. email in info. contact me offline.
voip dot ms has been good to me for many years now
I've been using flowroute for years now.
Twilio, voip.ms, or DIDlogic. Twilio may be for large users, but it works great for tiny ones as well. No minimums, simple wholesale pricing, and they still have free support even if you don't want to spend thousands a month for 24/7/365 phone support with an expert.