On the VoIP News website, Owen Linderholm has a very well thought-out piece entitled "Top 10 Questions To Ask Your VoIP Service Provider."
He goes into detail about each.
I am thinking I will just give you a taste by listing his questions.
1. What is the contract termination policy? Can I get out early and what penalty is there? Are there other termination costs?
2. What startup costs are there beyond setup and equipment fees? Besides advertised and quoted basic equipment, what else will I REALLY need? Do I need to buy phones? Will extra servers/cards/add-ons be needed beyond the base cost to actually meet my usage requirements?
3. What day-to-day usage costs are NOT covered by my service plan? What are the rates for international calls for example?
4. Can the system as it comes handle outbound and inbound faxes easily? Can I just plug a fax machine in or do I need special equipment?
5. Do I need add-ons or extras to handle old-style analog phones I already have or that remote or branch offices already have installed?
6. How does the system handle remote and mobile workers – whether temporary or permanent? Will the experience be the same for a telecommuter in a rural area as it is for someone at head office? How about when I'm on the road? Are there any services or features to handle that?
7. If I estimate my requirements wrongly and need a major upgrade, what will that cost me extra above if I had made the estimate correctly to begin with – in other words, what are the additional costs for upgrading?
8. How do you guarantee you Quality of Service? If I have issues how do I get support, who do I contact and how fast will it happen? When there is a complex issue and my network equipment supplier, my broadband supplier and you are all pointing the finger at each other, will you step up to solve my problem?
9. What about emergency services – do you provide full 911 or E911 services? Will dispatchers know my location automatically? How about remote workers?
10. How do I know you are going to be around in two years, let alone three?
Nice job, Owen. Readers, go there.