John Vollbrecht wrote:
I agree this is hard. I think levels and layers are different. Layers apply to protocol layers. I may misuse the term. Levels for me apply to what can be switched for a given topology. I.e. A given topology allows VLANS to be created ete, by concatenating VLANS at each edge point. The VLANS to be switched are carried on something else - SONET trunks, GOLEs, Ethernet trunks, etc. Level in this case refers to VLANs on one level and what carries them on the other.
A node in a network operates on a certain layer in the network protocol stack. The node switches, or routes based on (header)information from that layer, right? Using that definition, network encapsulated in VLANs are also in a layer on top of Ethernet (or other VLANs, or whatever you would want to encapsulate it in). Perhaps it's me, but I still do not see a difference between layer and level so far. Jeroen.