DC fiber cut: field report

Tue Jul 22 09:03:02 UTC 1997

> The story that I have heard is that some providers have 1 (one)
> protect circuit to cover many primary circuits...  You loose too
> many primary and limit number of protect circuits can't get them
> all.
> 	--asp at partan.com (Andrew Partan)

I'm not a TELCO wizard.

The impression I get is that the protection circuit is intended to 
cover failures that take out a single circuit.  For example, if you 
had 10 fibers in a system and a repeater or laser died, then only 
one of your fibers stops working.  Fixing that with a protection 
circuit adds 1/10 to the system cost.  (Maybe less if you have spare 
fibers in the ground.)  Fixing it with SONET ring technology roughly 
doubles the system cost. 

A protection circuit doesn't help if your problem is backhoes.