Switching systems Telecommunication 187 Examinations 40 Local area networks (Computer networks) 38 Certification 32 Electronic data processing personnel 25 Signaling system 7 21 Optical communications 19 Computer networks 18 Study guides 16 Signal processing 14 Internetworking (Telecommunication) 13 Telecommunications engineers 13 Routers (Computer networks) 11 Wireless LANs 10 Wireless communication systems 10 Computer network protocols 8 Security measures 8 Computer network architectures 7 Packet switching (Data transmission) 7 Signal theory (Telecommunication) 7 Telecommunication systems 7 Data transmission systems 6 Mathematical models 6 Mobile communication systems 6 Switching circuits 5 Traffic 5 Graphical user interfaces (Computer systems) 4 Integrated optics 4 Photonics 4