Physical layer
Layer 3
There are no layer 1 switches; switches run at layer 2 or 3. A hub is a layer 1 device.
Data-link layer
VSAT is a layer 2 device.
yes. thougth the nic is a layer 1 device its mac address is used in datalink layer
hub is the device that is used to extend the lan segment and used at layer1 that is physical layer.
layer 1 deal with physical connectivity of network device.Most common problems related to Layer 1 as follow: -device power off -device power unplugged -loose network cable connection -incorrect cable type -faulty network cable
Hubs are a physical layer (layer 1) device; most switches operate at the Data Link layer (Layer 2) of the OSI model.
Transport Layer
Switches are generally considered layer 2 devices, but many are capable of operating at layers 3, 4 or higher. Most hubs are amplifying the electrical signal; therefore, they are really repeaters with several ports. Hubs and repeaters are Layer 1 (physical layer) devices.
Each layer in the sending device adds its own information to the message it receives from the above layer and sends it to the layer below it. At layer 1 the entire package is converted to a form to be transmitted to the receiving device. On the receiving device side, the package is unwrapped layer to layer. Each layer removes data meaningful to it and sends the rest to the above layer and so on. Hope this was helpful By nour el houda