Securing the telecoms network is as important as protecting the data network, and Context offers a range of services designed to protect against attacks on telecoms networks. Unsecured telephone PBX, Interactive Voice Response (IVR) and Automatic Call Distribution (ACD) systems could be exploited by external attackers or internal staff intending to perpetrate toll fraud and the theft and resale of long distance call services, or trying to break into an organisation's networks via a back door.

This can be carried out in several different ways, including the setting up of premium phone numbers then initiating calls to that number for financial gain; or accessing and manipulating a switch in the PBX to make unmetered calls. There have also been incidents of criminals hijacking unsecured PBXs to make calls. Voicemail systems may also be targeted, as they can act as a channel through which it may be possible to access confidential information or eavesdrop on calls, and because exploitation of call transfer facilities can allow hijacking of lines for long distance or premium rate calls. Many abuses of telecoms network are initiated by employees or contract staff prepared to steal or sell confidential information.