I was under the impression that frame relay operates strictly under the data link layer of OSI model.
But now that i've researched over the net I get mixed results where some sources
include frame relay in the physical layer as well. What would you answer if you came
accross such question in CCNA?
Thanks for the link. Maybe part of my confusion stems from this:-
Data ---- Application, Presentation, and Session layer
Layer 4 - --Transport (Segments)
Layer 3 --- Network (Packets)
Layer 2 ----Data Link( Frames)
Layer 1 --- Physical (Bits)
So frame-relay layer 2. How can I relate frame relay to Bits?
Most of the frame relay services use T-carrier or E-carrier systems in telecommunication world. (http://en.wikipedia.org/wiki/T-carrier) Frame relay rely other standard and protocol to operate in layer 1. There is no layer 1 standard specific to frame relay. Although people sometime losely use between T-carrier and frame relay terms. (such as T1 wire pin-out and frame-relay wire pin-out)
Thanks for the diagram, very detailed
What I am worried about is questions like this:
At what layer of the OSI reference model does FRAME-RELAY
So if they say choose two(answer is F,B) and choose one(answer is F).
Message was edited by: chemilio