Can I keep my existing phone number?
Probably, but it depends on your carrier. The Local Number Portability (LNP) regulation does not yet affect all providers, but there is a definite trend to provide it, whether they are required to or not--simply because so many customers want it. There may be a lengthy delay however, in porting over your old phone number. While you're waiting, your VoIP carrier will provide you with a temporary number that you can use right away.
Can I call anyone using my VoIP service?
Yes, anyone with a phone. The person you call does not have to have VoIP service. Your VoIP carrier routes your call over an IP network, but has arrangements for access to the PSTN (public switched telephone network). As a result, while your call may originate on the Internet, it can still terminate on the PSTN, anywhere in the world.
Can anyone call me?
Yes, because of the same reciprocal agreements and FCC-mandated access to the PSTN, calls originating on the PSTN can terminate on a VoIP carrier network. A caller using a standard PSTN phone can call someone with a VoIP phone, the same way as they would place any other type of call.
Will my electronic devices like fax and home alarm work?
Some home alarm companies will not service you if you have VoIP. Electronic devices such as fax machines will still work with no problem, however. All you need to do is connect them to your router, which is then connected to your broadband modem.
Can I have multiple extensions?
Absolutely, you can have as many as your router will allow. Most simple home routers have at least five ports. One port is used to connect your router to your broadband modem. Assuming you also use a port for your PC, that leaves three other ports to which you can attach telephone extensions.
Can I dial 911 on my IP phone?
VoIP providers are required to provide what's called "Enhanced 911", or E911 service to its customers. Most of the major providers have already begun offering this service. The rule applies only to VoIP services that have an interconnection with the PSTN. The inherent limitation however, is that with a regular phone connection, the operator can easily obtain a caller's address. VoIP is mobile, and can be used from any broadband connection, anywhere--so there is no way for local emergency service providers to know where a call is coming from. A workaround is for each customer to register their address to the VoIP carrier's database, along with a possible alternate address, or another way of updating address information on the fly.
Can I use my own computer as a VoIP server and avoid having to use a VoIP carrier?
Yes, but for most home or small business uses, it's not necessary, and probably more trouble than it's worth. If you do wish to take this path, it is recommended that you use a separate, dedicated PC as a server in order to isolate your network from any attacks.
Is VoIP secure?
If you take normal recommended security precautions, yes. VoIP is subject to the same sort of attacks as your computer is when you access the Internet. Using difficult password settings, installing a firewall, and deploying antivirus software and keeping it current will protect you from almost every threat.