In article <980922233256.fe71@SDG.DRA.COM>, Sean Donelan <SEAN@SDG.DRA.COM> wrote:

In practice, I would expect excavators careful enough to have all the underground utilities marked ahead of time, are also careful during their digging.

Well, as you know there is no hope for us. When the contractor was digging a trench to install fiber to our building, they managed to cut the 20kV power line. It was marked. All you can do is put in enough redundancy to bring downtime to a level you(r customers) think is acceptable. I think MTTR is underappreciated and lowering it is probably the most cost-effective way to keep your percentage availability high. You periodic NOC contact checking is a good step there. -- Shields, CrossLink.