Telephone System Examinations

1. Objective
   
   The telephone is one of the greatest threats existing when listing potential areas of exploitation as it is one of the most common means of communication. The telephone is generally located in the most sensitive locations, thus constituting one of the greatest threats to audio security in that it provides a means of concealing and providing power for audio devices, and a path by which information can be carried from the area. These inspection procedures are designed to assist TSCM personnel in the detection of telephone systems used for audio penetrations. Whenever possible, telephones should be removed from areas designated as secure or sensitive.
   
   
2. Scope
   
   Inspection procedures generally applicable to all telephone systems are described in this appendix.
   
   
3. Required Materials
   1. System and instrument schematics and diagrams.
   2. Audio amplifier for examining existing wiring.
   3. Telephone Analyzer
   4. Tone generating device, to be used in conjunction with the audio amplifier.
   5. Tools.
   6. Radio Frequency Radio, to determine if an RF device is associated with the system.
   
   
   
4. Procedure
   1. System Examination
      1. Determine the complexity of the system, determine the number of instruments and locations involved.
      2. Physically examine the system, to include instruments, wiring and associated equipment to insure the system is properly installed.
      3. Using an audio amplifier, perform a terminal strip examination of the various wire pair combinations for indications of audio not generated under normal system usage. In this manner, as terminal strips have common lines for various instruments, it is possible to examine most or all instruments located in an area being serviced.
      4. Using analyzing equipment, thoroughly examine all conductors against each other and ground.
      5. Conduct a physical examination of each instrument and its associated wiring, looking for hidden devices or cross connections.
      6. Upon completion, reassemble the instrument and perform a system check for proper operation, to include lights, buzzers, switches, bells, etc.
   2. Local Intercommunications Systems. As with telephones, the intercommunications systems should be removed from locations where it is not required for operational purposes, especially sensitive or secure locations.
      
      Intercommunication systems may fall into two categories, the wired type which utilizes installed wiring or the wireless type which utilizes existing AC power to carry an RF signal between units. Wireless systems are the more insecure and should definitely be removed from serviced areas.
      
      
      1. Perform an operational check to insure the system is functioning properly.
      2. Examine all wiring and related equipment associated with a local intercommunications system in a manner similar to that of the telephone examination. Look for unauthorized connections or wiring leaving the cables.
      3. Examine the interior of the each unit. Examine relays and switches for evidence of tampering, bypassing or unusual appearance. Utilizing schematics and other available data, compare circuitry and components to insure there have been no additions, deletions or unauthorized modifications.
      4. Check for possible induction into other/adjacent lines