Good question. The problem with VoIP is that while it's great technology, the technology is so available anyone could start up a "VoIP Provider" in about half an hour. The trick is to separate the wheat from the chaff.
Here are some things to think about. You may not care about some of these depending on your specific situation. These are just general guidelines which you can use at your discretion.
- Are there any hidden fees for USF, etc?
- Can you get a business listing in your local white pages? Yellow pages?
- Can you get outgoing Caller ID Name?
- Must the cost of the equipment be paid up front, or is the cost rolled into the monthly fee? What equipment will they give you? Google the model number; does it get good reviews?
- Is the equipment "locked"? Can it be unlocked when you terminate your service? Is there a fee for this?
- Are you required to sign a contract? What if you're not happy with the service; can you break it?
- Can you "port" your number away to an alternate telecom provider, if you decide to terminate service? (If the answer is no...STEER CLEAR of this provider.)
- Do you have enough bandwidth for all the channels of VoIP you will require? Will you have a dedicated internet connection, or will you be sharing your internet connection with regular internet traffic? If the latter, what will you do for Quality of Service routing? Do you know how to set up QoS, or will the provider take care of that for you? (I HIGHLY recommend having a dedicated internet connection or shopping for a provider that will set this up for you as QoS can be very fiddly to get right, especially if you don't know what you're doing. Also, if anyone says that QoS is only possible for outbound traffic and not inbound, RUN FAR AWAY because they don't know what they're talking about. This is a very common misconception...but is absolutely untrue, and a professional should know better.)
- What city are your calls routed through? Is the VoIP provider's equipment relatively close to you, or is it routed through somewhere on the other side of the country?
- Does the provider have equipment in multiple cities for redundancy? Is failover automatic, or do you have to know what to do to switch in the event of an outage?
- Is technical support available during your business hours? If you work on weekends, is it available on weekends? What is the scope of their support, i.e., how much will they help you do and how much do you have to do?
- What does the VoIP provider do for fraud prevention? If you'll have a PBX, how will it be secured from brute force attacks? If you don't have a PBX, how is THEIR system secured from brute force attacks?
If you're Canadian, we use AcroVoice and have been delighted. If you're American, I've heard good things about Paetec. (I'm sure there are other excellent VoIP providers, Paetec is just the one I hear of most often.)
Good luck!