[c-nsp] Typhoon support on XRe

Mikael Abrahamsson swmike at swm.pp.se
Thu May 4 06:38:34 EDT 2017

On Tue, 2 May 2017, adamv0025 at netconsultings.com wrote:

> Oh dear, 16.67Mpps budget per 10GE is now acceptable? We're doomed.

This has been in the making for a long time. There have been plenty of 
offerings where the line rate min-packet size kept creeping up and up. 
Cisco 12000 wasn't line-rate until engine2, then engine5 started slightly 
skimping on that, engine 2, 4 and 6 are the only wirespeed POS linecards 
that I know of.

Even the CRS-1 tapped out around 80 bytes wirespeed rate if I remember 
correctly, and there is/was an ASR9k 100G LC that only will do around 
200-250 bytes minimum packet size (if I remember correctly, again).

So I'd say the market has spoken, people don't care about wirespeed 
anymore, hasn't for 10 years at least, and the market is catering for 
wirespeed forwarding at around 100-200 bytes min sized packets. If you 
want more than that, then you have to typically use fewer ports per NPU, 
if the internal wiring allows for that kind of "trickery" to get wirespeed 
out of the NPU by using less oversubscription of its capacity. Also, with 
fewer features the wirespeed performance might be a lot better than the 
worst-case specified by the vendor.

Going forward, it's not a bad thing to design your network to fit features 
commonly available in merchant silicon. People designing networks that 
require a "fully featured, classic-style core router" are going to 
discover that there is less and less focus on them, probably meaning 
significantly higher cost compared to the gear coming out that caters to 
the "less-complicated" networks.

Mikael Abrahamsson    email: swmike at swm.pp.se

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