Telecommunication Solutions
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Telephony Firewall

Basic functions

  • Analysis of calling and called party numbers and comparison with black- and white-lists
  • Detection of DTMF sequences in voice tract
  • DTMF distortion feature
  • Call record keeping
  • Can be integrated with access control systems


  • Blacklist mode
  • Create of groups of subscriber numbers
  • Black and white lists
  • Calling party number modification
  • Automatically reads external system configuration files
  • Transfer of information files to external server

Number Filtering

PROTEI Telephony Firewall allows calls to be filtered according to the source/destination number on the basis of ‘block’ and ‘allow’ lists. Filtration works on the basis of analyzing the whole number or matching prefix only.


PROTEI TFW can register information about calls processed by the system:

  • Information about all processed calls
  • Information about blocked calls

Information storage

Statistical information can be stored within the system as well as in an external database.

Integration with external systems

PROTEI Telephony Firewall can work with filter lists held in external databases


  • Control transit traffic
  • Filter transit traffic
  • Control traffic from connected operators
  • Protect switching equipment from external actions