On Thu, 4 May 2017, [email protected] wrote:
Well people don't care about a lot of things, like how routers actually work or whether they can still protect your EF traffic when overloaded, and that's not necessarily a good thing even though everyone does it. But I guess you're right, it's just I've got a feeling we're slowly getting ripped off here, I mean it's alright if the LC is marketed as oversubscribed, but it's certainly not alright if a LC can deliver what it's marketed for only under certain specific circumstances and it seems like this "nominal performance window" is getting narrower and narrower as the BW the LCs are marketed for is increasing. And you get told - use less ports then, or buy more LCs, or don't use these two features together.
I have been told this before purchase. "worst case performance with all features turned on, is X bytes wirespeed. Less features, higher pps. if you want wirespeed, don't use all ports, use 2 ports instad of 4 connected to that NPU, then it's wirespeed on those two ports". if this wasn't true, I would get upset.
Let's consider NCS5K -it's one of the "100GE for everyone at the bar" type of boxes, has an abundance of these dirty cheap 100GE ports, it might not have the most feature rich NPU but it would only ever do MPLS switching so no problem there. (Btw talking about raw performance, NCS 5001 is 35Mpps per 10GE) But does the NPU's architecture allow it to protect your EF traffic even when it's overloaded (under DDoS), I don't know I haven't checked/tested, I know ASR9K LCs would.
From people who like to look at theoretical edge cases, I've been told the
last major platform that did this was the CRS-1 with 40G per slot.
What I'm trying to illustrate here is that raw performance of the NPU is one thing, but there's also other dimensions that dictate the price and suitability of the HW for a certain project.
Absolutely.
For example if it's a network that can't get DDoS traffic in it and you know you're only going to have 60% utilization before upgrade, or all traffic is BE, then sure nothing to worry about.
I'd also say this isn't just about PPS. It's about other features. Designing a network with lots of feature-rich edge/core features mean you need platform that supports this. If you keep down the features required, you typically have more platforms to choose from.
But yes, I agree, the type of traffic you're expecting worst-case dictates what platforms you can choose and how to use them.
-- Mikael Abrahamsson email: [email protected] _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
