Introduction and guide to this document.
Organisations use many types of telecommunication services: fixed and mobile telephony, videoconferencing, internet, encrypted links between offices, etc. In the last decade, organisations have become much more dependent on these services. Whereas in the past a telephone outage was an inconvenience, today the failure of telecom services often makes it impossible to do business at all. And as organisations move online and into the cloud, reliability of telecom services becomes even more essential.
At the same time, technological and market changes have made it more difficult to assess the reliability of telecommunication services. Networks grow continuously, new technologies replace old ones, and telecom operators outsource and merge their operations. For any end-to-end telecom service, several telecoms operators will be involved, and none of them can understand how important that service is to each customer.
This increased dependency applies even more to organisations that fulfil a vital role in society, such as fire services, medical care, water boards, utilities, banks, etc.
It is therefore important that organisations in general, and organisations that supply critical infrastructures in particular, understand the vulnerabilities and dependencies of the telecom services they use. This document describes a method, called Raster, to assist in this understanding.
The goal of Raster is that the organisation becomes less vulnerable to telecom failures. To reduce the vulnerability, the organisation must first understand what can go wrong with each telecom service they use. Also, these risks must be ranked, so that the most pressing risks can be addressed first. Raster helps a team of analysts to map and investigate one or more telecom services for an organisation. The result is a report, showing which risks should be addressed first, and why. Selection and execution of countermeasures is the next logical step, but is not part of the Raster method.