Andre Oppermann wrote:
vijay gill wrote:
Moore's law for CPUs is kaput. Really, Moore's Law is more of an
observation, than a law. We need to stop fixating on Moore's law for
the love of god. It doesn't exist in a vacuum, Components don't get
on the curve for free. Each generation requires enormously more
capital to engineer the improved Si process, innovation, process,
which only get paid for by increasing demand. If the demand slows
down then the investment won't be recovered and the cycle will stop,
possibly before the physics limits, depending on the amount of demand,
amount of investment required for the next turn etc.
Predicting the future was a tricky business ten years ago and still is
today. What makes you think the wheel stops turning today? Customer
access speed will no increase? No more improvements in DSL, Cable and
Wireless technologies? Come on, you're kidding. Right?
Missing the point. We can deal with increased speeds by going wider, the
network topology data/control plane isn't going wider, THAT is where the
moore's observation was targeted at.
Also, no network I know is on the upgrade path at a velocity that they
are swapping out components in a 18 month window. Ideally, for an
economically viable network, you want to be on an upgrade cycle that
lags Moore's observation. Getting routers off your books is not an 18
month cycle, it is closer to 48 months or even in some cases 60 months.
When you are buying a router today do you specify it to cope with 200k
routes or more? Planning ahead is essential.
And we're paying for it. But again, assuming that the prefix/memory
bandwidth churn can be accommodated by the next generation of cpus. I am
not going to throw out my router in 18 months. Its still on the books.
Then we have the issue of an memory bandwidth to keep the ever
changing prefixes updated and synced.
Compared to link speed this is nothing. And nowhere near to memory
bandwidth.
Each update to and fro from memory takes cycles, and as the routing
tables become bigger, the frequency of access to the memory for keeping
the system in sync impose a larger burden. This is orthogonal to link speed.
/vijay