North American Network Operators Group

Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical

Re: Scalability issues in the Internet routing system

  • From: vijay gill
  • Date: Tue Oct 18 15:15:15 2005

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.