Well, it depends...
- What kind of reliability/stability are your looking for?
- Radio/wireless has issues with high temps (radiant heating) and inclement weather (rain, sleet, snow, clouds, etc.).
- DSL speeds are limited, and you'll struggle with any type of VoIP. VoIP traffic doesn't like to be converted from digital, to analog, to ATM, and back again.
- Cable and fiber are good options, but that also depends on the ISP. Some have horrible service, but most are pretty good.
- Don't forget about T1/T3...some areas don't have the above, so you might get stuck with a T1 or T3 connection.
- REMIND the customer site...Internet is best effort traffic, and NOT guaranteed bandwidth. Most Internet connections are shared somewhere along the path, and 80 users will have congestion issues from time to time. There is no QoS method for Internet traffic, and no way to prevent it from congesting. Set the expectation upfront, so you aren't explaining yourself all the time.
Other options, if you want to back-haul traffic to your data center and out that Internet connection:
- MetroE (point-to-point)
- MPLS (full Mesh)
D