Some security aspects of digital telephone exchanges

Abstract

Paper deals with security aspects of digital exchanges, assuming that modern digital exchanges are computer systems with special hardware. Functional requirements and design of exchange are the basis for security criteria and for analysis of possible attacks. Special attention is on internal structure of exchange software. Software correctness, overload conditions and software robustness are focused as system features with direct impacts on system security. Functional access points of digital exchange are listed, and for every of them possible attacking scenarios are described. Some of the design errors with security considerations are also presented. Paper concludes that security of telecommunication networks, if we apply computer systems point of view to the network, will be an area of increased interest.