Voice over IP service can certainly save a business money with in-state, inter-office and international dialing. Better yet, Hosted PBX service can deliver productivity gains to your business.

Virtual office space, tele-work, and tele-commuting provide for productivity gains and some savings - both for the employee and the employer. (Plus with virtual office, your talent pool extends beyond the local area).

Now that AT&T is closing its CallVantage VoIP service, many folks are looking for a replacement service. I keep seeing Vonage come up as a replacement. Is that because it has name recognition or because it is cheap?

For my business phone service, I want quality and reliability. I want my clients to be able to hear me on the phone and I want calls to go through.

I work with many VoIP providers including PBX-Change and FreedomVOICE.

There are directories of VoIP Providers.  Like this one from DSLReports.com, and this one from affiliate marketing company VoIP Review, and this one with over 600 providers in the US.

I wrote this in reply to a small business owner on LinkedIN:

There are many different VoIP Providers that can sell you Hosted PBX. Over 1000 in the US. Most of them offer the desired features. Some are based on Broadsoft, some on Asterisk, and some on a proprietary system.

What you want to get the best possible quality of service is to find a Hosted PBX provider that is directly connected (read: buying transit or peering with) the Internet Access Providers that your employees are utilizing.

For example, if 25 of you are on Comcast; 15 of you are on Qwest; and 10 are on other, you would want (in writing) that the VoIP Provider was directly connected to Comcast, Qwest and as many of the Other as possible.

Most VoIP Providers are connected to just two Internet backbones, so if you find one (like FreedomVoice) that is connected to 8 or more, you will likely see better quality.

You will want to do traceroutes to their gateways at different times of the day.