Which layer is the layer closest to the transmission medium.

physical network data link transport

The purpose of RS232C is to

establish a standard interface between terminals and modems. establish an interface between local and long distance lines convert serial to parallel data. convert digital data to analog data.

What is the frequency range of the IEEE 802.11b standard?

2.4GHz 5Gbps 2.4Gbps 5GHz

Which network topology is considered passive?

Bus Cross Ring Star

In which connection, more than two devices can share a single link?

multipoint point-to-point primary secondary