At 11:59 07-18-97 -0700, you wrote:
The thing that doesn't make sense to me in all of this is that SONET is supposed to be built as RINGS. With a Service side and a Protect side to each switch. BIFF should, in theory, only take out one or the other, but not both. WHY, with what we pay these carriers every month, do they not divergent-path route these critical wide-area links so that this isn't fatal?
The usual response is that carriers are over-provisioning lines (more than 50% of capacity used). Voice links usually get priority during rerouting; perhaps all the Tier-1 internet links are being provisioned in the "above 50%" section of the fiber, since Internet outages aren't as costly as voice outages. However, what if Backhoe Fade is far more common than advertised, and we only find out about cuts when BOTH sides of the rings are hit? Is there any practical way to measure/detect SONET failover from an endpoint? Stephen -- Unsolicited commercial/propaganda email subject to legal action. Under US Code Title 47, Sec.227(a)(2)(B), Sec.227(b)(1)(C), and Sec.227(b)(3)(C), a State may impose a fine of not less than $500 per message. Read the full text of Title 47 Sec 227 at http://www.law.cornell.edu/uscode/47/227.html