[e2e] TCP in outer space

Cannara cannara at attglobal.net
Sat Apr 14 22:13:18 PDT 2001


Was wondering who'd be the first to invoke "Moore's law", which is really just
"Moore's observation" on particular chip-fab techniques.  :]

Actually, network processors with OC48 capability are at hand and OC192 is not
far, since the step is >2:1 per year, unlike DRAM.  In 2 years, OC192 will be
a one, or two-chip system capability.  Just as now folks can address
multigigabit flows with a couple of 4-port, $250 devices.  Again, just follow
the announcements from the various NP houses, and note that their customers
have projects for deplotyment a few years hence that are designed for hundreds
of GB/s, line-rate packet processing.  If anything, packet processing is
increasing, per touched system, for security, flow-management and other
value-added features that can be marketed.

Happy Easter/Passover,

Alex


Pablo Molinero wrote:
> 
> Cannara wrote:
> 
> > [...]
> 
> >
> > I'd summarized some of this in a draft response to another msg., so will try
> > not to repeat anything.  The fact is that network processors are now available
> > that have (per chip) >500,000,000 RISC cycles available per second and >1GByte
> > fast RAM available for processing packets (corresponding to about 2M
> > packets/sec).  They also implement queue controls like RED in hardware.  Since
> > basic RFC1812 routing takes <200 such cycles per packet, we now have designs
> > emerging with well over 100 extra instructions available per packet to do
> > whatever.  MPLS numbers are similarly good.  All these numbers more than
> > double next year, and will reach 10Gb/s packet processing per chip about a
> > year later.  If someone is interested in processor vendors, I'll be happy to
> > pass names off list.
> 
> I find these numbers interesting.  Even if they are quite impressive, I
> think that that 2 Mpps is still far away
> from the 31 Mpps needed to treat TCP ACKs back-to-back in an OC-192
> link. According to Moore's
> law we would need 6 more years (doubling every 1.5 years) to see this
> processing power, but who knows
> what link rates we might be looking at by then.
> 
> My believe is that we are heading towards a situation in the core where
> we have fast links and slow routers.
> This comes from the observation that for the next 10 years link
> capacities will double every 7 months,
> whereas processing power will double every 1.5 years. As time passes the
> goal of designers will start
> shifting from making an efficient use of their links to reducing the
> amount of per-packet processing.
> 
> Pablo Molinero-Fernandez
> molinero at stanford.edu
> 
> >
> > The point is that router/switch code can do far more these days than ever
> > imagined when the decision to offload performance and capacity decisions from
> > 'gateways' (routers) was made years ago.  The corollary is that this is not a
> > surprising reality. 
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