Context offers comprehensive testing of all aspects of an organisation's telecoms infrastructure, to help protect clients against attacks on PBX, Interactive Voice Response or Automatic Call Distribution systems. Our PBX audit process provides a complete analysis of an organisation's telecoms hardware, processes and services, while we use a combination of war dialing and a telecoms hardware firewall (ETM) to analyse both inbound and outbound calls.

War dialing involves calling every extension on a telecoms network, and is an effective way of detecting most modems. But it can only detect modems that may be accessed by inbound callers, and not those set to make outbound calls. These may include internal laptop modems, which staff may be using to connect to an ISP in order to bypass content security or internet usage guidelines. This can expose an organisation to security threats if the laptop is also plugged into the corporate network, because although the laptop does not present a direct connection into internal networks, it does create a bridge across perimeter defences over which viruses or worms might pass. Outbreaks of the Sasser virus have been traced to this kind of unsecured laptop use.