Update from my ISP - the issue is with NBN Co the National Broadband Network provider in Australia.  My lightning network node likely wont be back up until Monday afternoon at the earliest which is when they will send out a technician to fix their faulty infrastructure.  

Makes you think - I have gone to a lot of effort to create stable LN infrastructure, UPS, 5 hour battery failover, etc but if there is a problem with the main link it's lights out until it's fixed.  I have a backup LTE connection as well but it doesn't fail over automatically so i'm looking into creating that auto failover for situations like this.

Thanks for your update. Good luck getting back up soon!

My internet link is back up now and my BTCPay Server and Lightning Network Node Chillycalendar is back online.  My apologies for the downtime.  I have asked NBN Co and my ISP for full technical details as to what went wrong with my fiber connection to the internet so I can add those details to a risk management document I'm working on for my business and for my startup and shutdown procedures.  Interestingly NBN Co didn't have to send out a technician or do any physical work in the network pit outside my property so it was definitely a problem at their end.  I thought it may have been a physical issue due to a 1 in 100 year storm we experienced in Spotswood 4 weeks ago which dumped a huge amount of rain and flooded the suburb.  I'm quite annoyed at this outage as I really went to great lengths to ensure my LN node would have excellent uptime.  Let's hope NBN Co don't stuff up again!
My ISP just sent me these details "the cause of this has not been given to us but it looks like the fix was resetting a Line Terminal Card. apart form that this is all the information we are provided"