Not everyone subscribed to NZNOG runs an ISP - some of us are consumers of Internet services and many of us advise our customers who are consumers of Internet services.
I sincerely hope, John, that your advise to customers who require Internet Access for business continuity, includes an if-all-else-fails backup plan. In my case, when Internet Access was a requirement, I for a long time maintained Dialup Internet Access with an alternative ISP over and above my DSL line. For the $2ish/month this may typically cost, its excellent insurance - phones tend to be more resiliant than DSL. I retain dialup access even now as a plan-b, but its no longer with an alternate supplier (If I get desperate, I drive to one of our office locations...) These days a higher speed alternative comms option may be a 3G card. Or Woosh, if available. If you have the option of Cable _And_ DSL, then this too might be a smart move.... it comes back to how much you're willing to pay for that insurance, right? Where you run services on the back end of a residential grade link - like say a Mail Server accepting mail via SMTP - that complicates the DR plan. You'd need an advertised Secondary MX and your secondary connection to have a Fixed IP. Not that hard, actually. If you're on entry level commercial-grade - Frame Relay as an example - you can be configured for ISDN Dialup on-demand backup, which can handle routed IP networks. Routers can bring the ISDN up as required, and routing protocols will handle this as a matter of course. Businesses that have come to depend on their consumer-grade internet access services should be prepared to survive for a matter of hours or days based on 'alternate comms'. This may include using your fall-back Internet to disable your online purchase or enquiry forms ('Contact us by phone or fax - sorry for the inconvenience'). It may simply mean you use your Business Internet Banking client over a dialup for a couple of days, and that whilst you're online your fax line is busy, so you don't dawdle. This seems pretty straight forward BCP to me - as most Internet Outages are generally resolved within no longer than say, 24-48 hours. More significant outages (out into the weeks) of any sort, well, I agree they're largely unacceptable. They're also (generally) a hellovalot less common - were they frequent, I imagine we'd see lots of service-provider hopping... (oh, wait, thats not always an option, is it...) (Sorry to dredge up a couple-of-hours-old tangent on this, but i'm posting to the list in the hope that other posters who may perhaps not be in the NZNOG target audience might see some value in it.) My personal thoughts. Regards Mark.