Packet switching (Data transmission) 120 Computer networks 34 Telecommunication 20 Routers (Computer networks) 15 Computer network protocols 14 Asynchronous transfer mode 10 Optical communications 10 Data transmission systems 9 Examinations 9 Management 9 Multicasting (Computer networks) 9 Traffic 9 Global system for mobile communications 8 Internet telephony 8 Broadband communication systems 7 Switching systems 7 Certification 6 Mathematical models 6 Routing (Computer network management) 6 Coding theory 4 Digital communications 4 Electronic data processing personnel 4 Equipment and supplies 4 Integrated services digital networks 4 Internet 4 Local area networks (Computer networks) 4 Multimedia systems 4 Network Time Protocol (Computer network protocol) 4 Network processors 4 Quality control 4