Port configuration is ambiguous..

Posted May 13, 2025 10:45 UTC (Tue) by paulj (subscriber, #341)
In reply to: Port configuration is ambiguous.. by farnz
Parent article: Making the OpenWrt One

> if we'd wanted 20G service, we'd have had to have 3 links, two primary and one failover to cover "backhoe fade" between us and our ISP.

You also need to obtain survey maps of where they have physically have placed their fibre, and /verify/ any claims they make about path independence of the fibres. Potentially down to hiring independent surveyors to verify such claims.

A certain large tech company lost connectivity for DC for a while once, discovering in the process their fibre suppliers had lied^Wwere mistaken in their claims about physical independence, when a JCB somewhere took out in 1 go a number of bundles of fibres that were not meant to be anywhere near each other. They significantly increased the level of verification of future supplier's claims after that.

Port configuration is ambiguous..

Posted May 13, 2025 10:57 UTC (Tue) by farnz (subscriber, #17727) [Link]

We wouldn't have needed to do any of that - the reason for redundancy was not because we wanted it, but because our ISP insisted on it as part of the service (since the service came with a 6 hour SLA, after which they'd be paying out).

If the claims about diverse pathing turned out to be false, that would have been our ISP's problem - they'd have been paying out on a 6 hour SLA while chasing their suppliers to fix it ASAP.

And we'd agreed an SLA payout that was large enough that the business was better off with the Internet link down than with it up; we weren't foolish enough to believe that a "business" service meant it'd be prioritised for repair, but did believe that if we were getting more in SLA payouts than it was costing us to get alternatives (like LTE sticks for everyone), we'd be OK.