[j-nsp] Juniper PTX1000

[Saku Ytti]

On 17 December 2016 at 19:18, Hannes Viertel <hviertel at bastelbude.net> wrote:

Hey,

> the PTX1k with the routing license can run both easily…  i could give another couple of examples where both Juniper and Cisco charge you a premium but in return you get a grown-up OS with a relative complete feature list… ( and yes sure you hit PR’s here and there.., but i believe we all agree there is no bug free sw in the market )
>
> but again, if the black art of flex route magic works for you and you don’t plan to  have  more than 2m-3m RIB routes while doing no sophisticated mpls scenarios like PCE initiated RSVP-TE i think it can be feasible. If you want to run it as a peering router on a large IXP with traffic engineering in your core * i  * would place a ptx1k there.

NCS5k (non SE) does same 'black art'. And I'm not sure why it's
brought up to be so big issue, I'm sure vendors have always tried to
make software which most efficiently uses available HW. Heck, we're
still figuring out novel ways to do stuff in C64.

The fact that Arista and NCS5k use exact lookups and LPM lookups in
parallel to scale FIB size IMHO shouldn't be held against (or for)
them. Do we know how PTX1k works? I don't, but on that basis who am I
to say NCS/Arista work in 'black art' way, when I have no idea how
PTX1k works.

If I were to guess, I'd guess PTX1k does only exact match lookups and
uses on-chip bloom filters to know which external mem exact match
table(s) to consult. If so, then it's also doing pretty similar thing
as Arista/NCS5k, only arguably in far more complex or 'black artsy'
way.


-- 
  ++ytti