There were several types of calls that I would get called in for that I could lump into three buckets. The lion’s share of the incidents were due to application and network changes that were not properly documented. Only once in my memory was the firewall actually they problem. Companies and organizations need to have repeatable processes to ensure people know what is their job is an emergency situation in emergency situations, says Kellan Kellan. The last on-call incident that I had to respond to was a whopper.”]
Source: https://www.csoonline.com/article/2138941/security-on-call-nightmares.html