I'd also add - verify at least a day ahead that those on-call know they are on-call and those making such calls - know who to call. Nothing worse than getting

I'd also add - verify at least a day ahead that those on-call know they are on-call and those making such calls - know who to call. Nothing worse than getting a call and that's the first you find out that your on-call. Experienced that before. One classic was for a some telco circuits running the DOH phone system about 9pm at night after I'd happily enjoyed a large helping of vodka. Which as I wasn't on-call or had any on-call responsibilities and worked on the Video Conferencing side - well, calls like that soon sober and wake you up with adrenaline. Lucky managed to assist and wasn't major or impacting and turned out the Telco providing the circuits had contacts mixed up and because I'd been diagnosing some circuit issues (turned out Q bearer needed replacing and video shows bit errors more than anything else like networking or voice and worked fine upon that Q bearer) the previous week that I got dragged into the mix. That was fun and was provider mixup. The other classic - was working for a mobile company and had just flown from EU to Seattle and again after a few beers (seems to be a theme) to settle jetlag and about 11pm at night I get a call. Turns out I was on-call, which as I hadn't done on-call up to this point - was not the way I wanted to break that cherry. So - making sure those on-call know when they are on-call and checking a day before to verify and those making the calls have the correct contact details is very much important as those two incidents highlight.