I made a rather strong statement with an individual during a meeting this week that really should more appropriately have been vetted with the rest of the community instead - so, here I am.
In the classic model, we have traditionally considered the layer immediately below IP (L3) as the link layer (L2). But, in some common scenarios there is actually quite a lot that goes on below IP but above the datalink. Some have called this "L2.5", but I find that term to be misleading because it seems to imply that there is one and only one functional layer between L3 and L2 and that does not accurately capture all scenarios. I wrote a draft that tried to address this by re-introducing the legacy OSI terminology which specified a 3 sublayer decomposition of L3 (the internet sublayer (L3c), the subnet enhancement sublayer (L3b) and the subnet access sublayer (L3a)). But, even this more specific terminology suffers from hazy distinctions between what belongs in one of the sublayers as opposed to another. So, can we simply call it the "sub-IP layer" as opposed to the other alternatives? "Sub-IP" makes no statement about any layering structure that may occur immediately below IP, and as such it allows for any level of mechanisms that may need to be implemented below IP down to and including the (classical) link layer. The term can also be used even if there is no intermediate mechanism at all, since L2 is by definition a "sub-IP" layer. In summary, I belive there is no one precise way to call the mechanisms that might occur immediatley below IP so can we just collectively call them: The "sub-IP layer" Thanks - Fred [EMAIL PROTECTED] _______________________________________________ Int-area mailing list [email protected] https://www1.ietf.org/mailman/listinfo/int-area
