Computer Networking
The physical layer, in reference to the OSI model, defines

All of these
the virtual circuit interface to packet-switched service
the interface between the X.25 network and packet mode device
data link procedures that provide for the exchange of data via frames that can be sent and received
None of these

ANSWER DOWNLOAD EXAMIANS APP

Computer Networking
MAC is

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

ANSWER DOWNLOAD EXAMIANS APP