I have read that the layer 1 SONET technology is sort of obsolete. We still talk about it because it is still around and investments still have to be completely amortized....
Things are moving towards IP over WDM (I guess that is for WANs).Before it was IP over ATM over SONET over WDM. Now we can do straight IP over WDM. That sounds better because we are skipping the ATM and SONET protocols and rules. That makes things faster I guess, does it?
All types of traffic are become straight IP. Voice and Video as well. In the past they were only based on circuit switching networks.... Now they are IP. Does everone agree that it does not make much difference if they are IP now? Or did they lose something, the same as film photography versus digital photography? thanks student25
I think you are conflating digital and analog. Digital processes data in discrete quanta. If enough bits are used the end result is indistinguishable from the analog original.
I think the other question you are asking is does IP over Sonet make more sense then IP over Ethernet.
Sonet was designed from the beginning as a long distance carrier class transport technology. Ethernet on the other hand was designed for short low cost commercial networks. Ethernet lacks a lot of the manageability and redundancy that is a key requirement for carriers. IEEE is working the extend Ethernet application deep into carrier networks but it is still a work in process.
ATM is well past its sell by date. The small cell size used for ATM made sense when communication networks were slow to reduce latency. Today there is not much reason to use ATM except to support legacy networks.