The key requirements for this scenario are as follows:
In this scenario, a geographical survey company has a main office and a branch office connected with a 1+GBps hardlink network connectivity. Each office has an identical infrastructure setup. All surveyors use mobile devices such as tablets for their survey work. The survey software autodetects which office IP is live and sends data to the infrastructure of that office. All data is replicated on a block level in real-time between two offices.
If the infrastructure of one office becomes unavailable, the staff can simply continue to work out of infrastructure from the other office.