How bad is serial encapsulation over Radio, and is that the only concern?

[harryting]

Can you get a service level agreement from the cellular vendors that specifies damages for downtime?

We have a company wide agreement with a very large cell co. They are actually putting in repeaters for us in remote locations.

While I doubt they be willing to do an agreement like that, I see no reliability issue with their infrastructure. I can't recall a single instance of outage in the last few years we have this going. Due to cost, it wont' be my first choice but there are benefits like I can just connect up to remote site as if the equipment is right next to me without involve large amount of IT effort.