North American Network Operators Group

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RE: 10GE router resource

  • From: Lincoln Dale
  • Date: Thu Mar 27 02:52:25 2008

> That said, it
> is notable that Cisco is now running their latest announced hardware,
> primarily the Nexus 7000's and ASR's, run a Linux kernel and IOS on top of
> that.

Moore's Law may have helped software packet forwarding rates but there's still
2 to 3 orders of magnitude performance difference between hardware & software.

just to be clear about a few things:

in the case of Nexus 7K the control-plane runs atop of Linux, data-plane runs
entirely in custom packet forwarding ASICs distributed on the I/O (linecard)
modules.  N7K never drops to "software forwarding".  the first forwarding
engine in N7K does 60M PPS with all features enabled.  i.e. you could be
performing ACLs on port, VLAN & routed on both ingress & egress, doing netflow,
policing, QoS, whatever - its still 60M PPS.

you'll see that pps numbers scale upwards as the product progresses through its

Cisco doesn't make any secret of N7K running atop of Linux, the reality is that
it doesn't have to be Linux, it could be any SMP/multi-threaded capable
POSIX-compliant kernel, it just so happens that Linux makes sense for a variety
of reasons.

Also, perhaps pedantic but just to be absolutely clear: N7K doesn't run on IOS,
it runs on NX-OS.

ASR is slightly different, it can perform packet processing in software (IOSd)
however that is really only meant for things that don't make sense to implement
in what is now called the QuantumFlow programmable processor.  e.g. if you
needed your AppleTalk or Vines running at millions of packets/second, then i'd
argue you have bigger problems. :)