Vonage's business system also offers a rich array of features, but came in more expensive, and may be more than your small office needs. With the exception of the call center, our winners all happen to be VoIP service providers. If you still cherish your PBX, you'd likely be very happy with Cisco (the largest networking company in the world) or Avaya (flexible for between 100 to 2,500 users) which are universally highly-regarded systems. These two are essentially the Cadillac and Porsche of the phone industry. However, most small businesses would find a Honda or Toyota does the job just as well.
We've assessed the plethora of business phone systems available, taking into account pricing, contract terms verses month-by-month rates, mobility options, customer service, customer and expert ratings, ease of use, and the company's standing with accredited reviewing entities like the Better Business Bureau. We also kept the following musts in mind:

I have a confession to make: I haven’t recorded a new voicemail greeting since 2014. In the past four years, I (hopefully) have become more articulate, poised, and self-assured. But hear my voicemail recording, and you’d think I was still new to the work world, a little unsure of myself — and probably not an authority. Obviously I need toupdate it. And if you haven’t changed your voicemail greeting in over a year, you’re likely in the same boat. After all, a professional voicemail recording boosts your credibility, makes you seem more competent, and encourages whoever’s listening to it to continue the relationship. A relatively unprofessional one — like mine, for instance — does the opposite: It encourages prospects, recruiters, and potential connections to run in the other direction. With that in mind, I’ve written 18 unique voicemail greetings for every situation. Pick your favorite, practice a few times, then record your new voicemail.
As far as pricing goes, costs will vary from provider to provider. Some basic VOIP plans only require users to pay government-mandated 911 fees, which helps keep costs low. Of course, as with most things in life, you get what you pay for. Basic VOIP plans may not include many of the advanced features that you’re looking for. The good news is that most VOIP providers offer clear, transparent pricing on their website with each tier displaying the features it holds. This makes shopping and comparing very easy.