Designing WAN Availability
One of my hot topics in my past that I haven't seen written about often is the calculation of WAN availability and what the design is built for. There is often the number of 9's whether that is 5 9s or 3 9s or otherwise, where do you start? Well, in the past the post by EventHelix.com outlines system reliability. It talks about designing systems in parallel and in serial. What does that mean. Well, I am going to take the system availability and bring it into the Wide Area Network, which really could be brought to any environment that has a system uptime requirement as a way to calculate and validate the dollars that you are requesting. I am hoping that this will help you to be able to answer questions such as "What if we added another service provider?" or "What if we changed out hardware for a smaller/larger hardware choice?".