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Comment by la64710 | Hacker News Reader

Great engineering but how does this 800Gb/s throughput achieved translate downstream all the way to the consumers? I suspect there may be switches and routers from ISPs and others that Netflix do not control in between that will reduce the effective throughout to the end user.

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The 800 Gb/s isn't going to a single user. There are switches and routers in the middle, sure, but they are all doing their job, which is to split up traffic. The end user only needs ~8 Mb/s for a 4K stream.

ISP routers have been more-or-less indistinguishable from switches for decades at this point. They're all "line rate" which is to say that regardless of features, packet size, etc they'll push traffic between interfaces at whatever the physical link is capable of without breaking a sweat.

In the case of Netflix it is in the ISPs best interest to let them push as much traffic to their customer eyeballs as possible. After all, it's much "easier" and cheaper to build out your internal fabric and network (which you have to do anyway for the traffic) than it is to buy and/or acquire transit to "the internet" for this level of traffic.

Modern routers are unable to do line-rate regardless of packet size. See for example the Q100 ASIC from Cisco. Rated for 10.8 Tbps, it is only able to achieve 6 Bpps [1]. So it needs 200-byte packets to hit line-rate. However, as for Netflix, this is not problem since they only push big packets.

[1]: https://xrdocs.io/8000/tutorials/8201-architecture-performan...

Wow, I've been out of this space for a while! Last I was paying close attention to any of this 10G ports were new. Glad I learned something from my old life today!

I stand corrected on "always line rate all the time in any circumstance" but by your math and my general point < 1 Tbps from one of these appliances across multiple 100G ports isn't problematic in the least from a hardware standpoint - especially for the Netflix traffic pattern with relatively full (if not max MTU) packets.

On the contrary, even older routers can handle this load with no sweat. Service provider-grade routers can handle 10 to 200 Tbps depending on size.

But then it gets to my home and it’s trashed down to 100Mbit/s

That would be more than enough to watch half a dozen Netflix streams at the same time.

Of course—the fat backbone pipe is progressively split into smaller pipes as it gets to your house. The internet isn’t a big truck. It’s a series of tubes.

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