Joshua M. Grooms
The Open Systems Interconnection model, or the OSI model, is a way to sub-divide a communications system into smaller, more manageable parts known as layers. A layer is a grouping of functions that have similar purpose that either provide services to the layer above it or receives services from the layer below it.
On which layer of the OSI model do WAN protocols operate?
WANs are managed by the protocols that exist in level 2, the Data Link Layer, of the OSI model.
What are some of these protocols?
Connection-orientated WAN data link protocols, in addition to framing, detect and may correct errors. They are also capable of controlling the rate of data transmission between two connected networks. A WAN Data Link Layer might implement a sliding window flow control and acknowledgment mechanism to provide reliable delivery of frames which is the case for SDLC and HDLC, and derivatives of HDLC such as LAPB and LAPD.
On which OSI layers do switches and router operate?
The first layer of the OSI model, the Physical Layer, is the layer that manages the relationship between devices and a transmission medium.
If routers reside on more than one layer, what is the difference between the OSI layers?
To the best of my knowledge, and after much research, routers reside on both the Physical layer and the Data Link layer. The Physical layer seems to manage all of the logistics of the device residing on the network (such as pins, voltage, cable specification, etc.) whereas the Data Link layer is responsible for the addressing of the device to give it the ability to transmit and receive data from other