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Author Topic: Petabit scale router  (Read 922 times)


  • Addicted Kitizen
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Petabit scale router
« on: May 03, 2018, 02:06:46 AM »

In the UKNOF presentation by BT’s Neil McRae (a good local name, makes me think of the mainland here near the bridge) he mentioned a ‘petabit scale router’ maybe Nokia I couldn't quite tell. Is that just a bit of theoretical hyperbole?

Forgive my ignorance, I just imagined terabit routers were pretty rare or non-existent, but maybe I'm wrong. Wouldn't you use several routers though instead anyway? For reliability I would have thought there is a reason not to pay through the nose for completely crazy kit and have more units that are slower but far cheaper. But then perhaps there is the power consumption and the problem of load sharing.

It might have been this device he referred to -

The blurb says 480 * 100Gb ports and 0.5 Pbps of switching capacity. Pretty mind-blowing. They said that BT handles 10 Tbps of traffic on a rough day sometimes, when something called football is happening.

Is this just cheating and making the box bigger and bigger so you can cram larger volumes of hardware into it, or is that unfair? (If I duct-tape another unit onto the side, and put the whole lot inside a big cardboard box, does that make a real >1Pbps router?)

I don't see where the increases in traffic will come from, neglecting the third world where more humans need to get internet access still. There isn't more data we want to access, but perhaps that will change.

I think Neil kind of admitted this, saying that we don't know what is going to happen. What use is 800Mbps on a mobile phone, it's only a phone and not very easy to use compared to larger devices so not necessarily a preferred platform for storing fat chunks of data and syncing or replicating it say to produce a demand for lots of bandwidth. If anything, I think I read somewhere that Netflix is getting less bandwidth hungry, because of much improved clever maths and powerful processors that can realistically decompress video despite the need for very complex algorithms. My experience is that video downloads have got a lot less taxing over the last five years or so. Some things use more like three or four Mbps instead of five or six. I never have the slightest problem with streaming video despite only having 7Mbps (7.7Mbps depending on which speed tester you use) of real downstream bandwidth.


  • Kitizen
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Re: Petabit scale router
« Reply #1 on: May 07, 2018, 09:13:34 PM »

They aren't single chassis, they're a bunch of them with optical cross connects. In common with everything else routing is getting more and more about the stack and decoupling control plane from forwarding plane.

A single management node and tons of line cards knitted together with backplanes and switching fabrics as a virtual chassis.
WiFi: Nighthawk® AX12 RAX120
Routing: pfSense VM
Switching: Mikrotik 2* CRS305-1G-4S-IN, 1 * CRS309-1G-8S+; various cheap and cheerful TP-Link/Netgear
Exchange: Wakefield
ISP: BT Full Fibre 900. Zen Full Fibre 900.