Computer Networking
X.21 is

None of these
a method of determining which device has access to the transmission medium at any time
a very common bit-oriented data link protocol issued by ISO
a method access control technique for multiple-access transmission media
network access standard for connecting stations to a circuit-switched network

ANSWER DOWNLOAD EXAMIANS APP

Computer Networking
Synchronous protocols

transmit characters one at a time
allow faster transmission than asynchronous protocols do
are generally used by personal computers
are more reliable
None of these

ANSWER DOWNLOAD EXAMIANS APP