Anyone know if comcast is considered a VOIP......
The most accurate answer is yes, Comcast uses VOIP to provide phone services but Comcast phone is acceptable for use with Apple. It is what they consider to be a "digital" phone service. What they don't want is Vonage, Packet 8, Magic Jack, or other VOIP services that connect to your existing ISP. You can use a phone service provided by your ISP. The real question you must ask yourself is about reliability. I worked for a cable ISP for 8 years before joining Apple and I must say that the service I supported was generally not as reliable as service you can get from a traditional POTS carrier. Just use your best judgment and use what's best for you.