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