单项选择题
A. addition of strict firewalls B. limiting Internet access C. intelligence on foundation network devices D. increased use of network services
A. equipment defects B. equipment failures C. complex network operation and management issues D. integrating mixed vendor equipment
A. converging voice， video， and data onto one network B. using IT services to improve revenue C. minimizing the total cost of ownershippf the network D. updating obsolete infrastructure