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New Optical Form Factors for 400 Gigabit Ethernet

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Re: New Optical Form Factors for 400 Gigabit Ethernet

#51

Post by Retric »

walrus01 wrote: post #46
Retric wrote: post #38

Earlier quoted context omitted.

According to the link that's currently limited to 2 GB/s which far to slow to use for this. Phantom v2640 needs ~50+x that speed to do it in real time and I assume the bandwidth needs will keep increasing on the next model.

So what storage device does it use currently? except for RAM, there is not much faster than a NVME based, PCI-Express 3.0 x8 interface SSD. If it's some truly ridiculous bitrate it probably uses proprietary packs of RAM with battery backing.

Ok, found more info on that model right now it's got up to 288 GB of internal RAM. At 12 bit per pixel which is lower than I thought that lasts 7.8 seconds for ~40Gbit/second.

Anyway, as this is all internal so they have a lot of options.

Re: New Optical Form Factors for 400 Gigabit Ethernet

#52

Post by dweekly »

walrus01 wrote: post #26
dweekly wrote: post #20

Earlier quoted context omitted.

It's a fair question; I suspect most of the reason for the lag is that consumer internet connections rarely offer >1gbps, consumer LAN applications requiring >1gbps of traffic haven't emerged (for NAS/SAN, a directly connected USB 3 is probably the way to go for 10gbps transfer, which is what you're looking for here), and WiFi - how most people are connecting their consumer devices to the network - doesn't offer more…

one of the major use cases for 802.3bz is high bandwidth WAPs, specifically things that can actually pull more than 1 Gbps of data... to actually achieve that with wifi standards usually requires: 1) dual, separate 2.4 and 5.x GHz radios 2) 3x3 MIMO 3) 802.11ac wave2 (1024QAM) 4) use of really wide channel sizes, even an 80 MHz wide 802.11ac channel won't get near 1 Gbps aggregate throughput, needs to be the ridiculo…

Spot on...and it is going to be a while before a typical home has those needs or capabilities. Broader FTTH could change bz and ac wave 2 adoption curves as people end up annoyed that they are paying for a gigabit but not actually receiving it.

Re: New Optical Form Factors for 400 Gigabit Ethernet

#53

Post by walshemj »

deaps wrote: post #4
bjoli wrote: post #2

Does aanyone here work with consuming (not just passing it kn) these amounts of traffic? How do you manage to get anything meaningful out of it?

Network Engineer here as well - I support one of the world's largest enterprise organizations (although my area of 'expertise' is pretty far down the stack - somewhere between the internet and the WAN circuits) - I can see no personal use for a 400 GbE port on anything. As far as my organization goes, there will always be a bottleneck somewhere else (speaking location to location across the WAN). The only application…

HPC Clusters would be one candidate

Re: New Optical Form Factors for 400 Gigabit Ethernet

#54

Post by walrus01 »

Retric wrote: post #51
walrus01 wrote: post #46

Earlier quoted context omitted.

So what storage device does it use currently? except for RAM, there is not much faster than a NVME based, PCI-Express 3.0 x8 interface SSD. If it's some truly ridiculous bitrate it probably uses proprietary packs of RAM with battery backing.

Ok, found more info on that model right now it's got up to 288 GB of internal RAM. At 12 bit per pixel which is lower than I thought that lasts 7.8 seconds for ~40Gbit/second. Anyway, as this is all internal so they have a lot of options.

yeah, if we're talking about RAM, there is still a significant difference in MB per second write ability for something like DDR4-3200 vs even the best NVME pci-express flash-based SSDs.

Re: New Optical Form Factors for 400 Gigabit Ethernet

#55

Post by agoodthrowaway »

walrus01 wrote: post #36
agoodthrowaway wrote: post #32

Earlier quoted context omitted.

100G/wave device will be the norm moving forward and 8 lane devices for 400G won’t be around much except in niche applications.

for long reach, yes, but not for ISP-to-ISP interconnection... the cost of coherent (QPSK, 8PSK, 16QAM) 100G SerDes and modulation/demodulation is considerably higher and only justified if going a great many km. For intra-peering-facility connections I don't see coherent 100G (or multiples of coherent 100G bundled by CWDM into 200G, 400G interfaces) becoming the norm anytime soon.

We aren’t talking about long distance and coherent here but direct detect. Coherent is not cost or power competitive with direct detect for short reaches yet.

When I talk about SERDES I’m talking about the electrical signal interface to the optic. Also it’s worth noting that the majority of coherent DWDM interfaces are some kind of embedded optic already.

Re: New Optical Form Factors for 400 Gigabit Ethernet

#56

Post by Dylan16807 »

gsich wrote: post #50
Dylan16807 wrote: post #45

Earlier quoted context omitted.

Sending twice as many packets and losing 1% of them should be playable.

Maybe if you send some packets twice. Otherwise no. Packet loss is deadly.

I would go so far as to say that netcode for an FPS is objectively wrong if it's not sending data in a redundant form that can tolerate lost packets.

Re: New Optical Form Factors for 400 Gigabit Ethernet

#57

Post by jdabney »

walshemj wrote: post #53
deaps wrote: post #4

Earlier quoted context omitted.

Network Engineer here as well - I support one of the world's largest enterprise organizations (although my area of 'expertise' is pretty far down the stack - somewhere between the internet and the WAN circuits) - I can see no personal use for a 400 GbE port on anything. As far as my organization goes, there will always be a bottleneck somewhere else (speaking location to location across the WAN). The only application…

HPC Clusters would be one candidate

We use 100 Gb EDR Infiniband to each host in our HPC clusters and with a combination of file system access, message passing, and general network traffic we actually use that bandwidth.

Re: New Optical Form Factors for 400 Gigabit Ethernet

#58

Post by gsich »

Dylan16807 wrote: post #56
gsich wrote: post #50

Earlier quoted context omitted.

Maybe if you send some packets twice. Otherwise no. Packet loss is deadly.

I would go so far as to say that netcode for an FPS is objectively wrong if it's not sending data in a redundant form that can tolerate lost packets.

Tolerate yes, but it will still have an impact. In case of an online shooter, resending it will cost an additional RTT. If that resend is even happening, the next packet will make the dropped one obsolete.

Re: New Optical Form Factors for 400 Gigabit Ethernet

#59

Post by drewg123 »

bjoli wrote: post #2

Does aanyone here work with consuming (not just passing it kn) these amounts of traffic? How do you manage to get anything meaningful out of it?

I'm not consuming it, but I can produce over 100Gb/s of traffic from a single CDN node if it is equipped with multiple 100GbE NICS. So 200GbE and 400GbE are exciting to me.

(for context: https://medium.com/netflix-techblog/serving-100-gbps-from-an...)

Re: New Optical Form Factors for 400 Gigabit Ethernet

#60

Post by Dylan16807 »

gsich wrote: post #58
Dylan16807 wrote: post #56

Earlier quoted context omitted.

I would go so far as to say that netcode for an FPS is objectively wrong if it's not sending data in a redundant form that can tolerate lost packets.

Tolerate yes, but it will still have an impact. In case of an online shooter, resending it will cost an additional RTT. If that resend is even happening, the next packet will make the dropped one obsolete.

Resends in an FPS are for dire scenarios, not 1% loss. 1% packet loss can be easily obsoleted and compensated, and the general performance of having 126/128 packets can be better than 60/60.
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