nanog mailing list archives

Re: [c-nsp] LDPv6 Census Check


From: Saku Ytti <saku () ytti fi>
Date: Thu, 11 Jun 2020 20:19:04 +0300

On Thu, 11 Jun 2020 at 19:49, Phil Bedard <bedard.phil () gmail com> wrote:

As for normal v6 forwarding, the way most higher speed routers made recently work there is little difference in 
latency since the encapsulation for the packet is done in a common function at the end of the pipeline and the 
lookups are often in the same memory space.  NPUs are also being built today with enough on-package memory to hold 
larger routing tables.   Whether a packet has to be buffered on-chip vs. off-chip has a much larger impact on 
latency/PDV than a forwarding lookup.

On-package is not important, on-chip or off-chip is what matters, i.e.
do you eat SERDES to connect memory or not.

Of course you could always implement a software feature that says
these 32b/32 or 128b/128 addresses are blessed and need to live on
tiny on-chip memory and from this CIDR we guarantee all are host
routes. To achieve similar-to-MPLS performance, with few more bytes
per number.

The demand is, we need tunneling, then the question is what are the
metrics of a good tunneling solution. By answering this honestly, MPLS
is better. We could do better surely, but IP is not that.

-- 
  ++ytti


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