The CCITT Recommendation X.25 specifies ______ three layers of communications.
A. Application, presentation and session.
B. Session, transport and network.
C. Physical, data link and network.
D. Data link, network and transport.
Answer:C
The CCITT Recommendation X.25 specifies ______ three layers of communications.
A. Application, presentation and session. B. Session, transport and network. C. Physical, data link and network. D. Data link, network and transport.