Some can be addressed quite cheaply, but it can be costly to provide alternative equipment, paths and sites. Organisation and staffing Where organisations work together, for example in MANs, it is common to operate as friendly consortia without legal status or formal contractual arrangements. This could lead to problems such as confused responsibilities and inadequate response to incidents. Capacity risks Network traffic grows inexorably and, when demand exceeds capacity, this leads to compromised quality of service and sometimes to total breakdown. Security Computer rooms should be secure and physical access to network equipment should be limited to authorised individuals.
Viruses are also a growing threat, affecting users and whole sites.
The TAU report1 identified a substantial number of important risks to network operation and assessed the probability and level of impact of each one, leading to an ordered list of the main risks. What Institutions Should Be Doing Local arrangements are a vital part of the service seen by individual users. Raising the level of reliability needs careful thought and planning. The first stage is to study the risks in the local network. Issues to be addressed include organisational responsibilities, staffing, training, security, equipment, communications links and power supplies, as well as network design.