Routed optical networks

Thu May 11 07:33:58 UTC 2023

But it is speculation, not a trend yet.
I remember 10y ago every presentation started from the claim that 100B of IoT would drive XXX traffic. It did not happen.
Now we see presentations that AI would be talking to AI that generates YYYY traffic.
Maybe some technology would push traffic next S-curve, maybe not. It is still speculation.

The traffic growth was stimulated (despite all VNIs) by 1) new subscribers, 2) video quality for subscribers. Nothing else yet.
It is almost finished for both trends. We are close to the plateau of these S-curves.
For some years (2013-2020) I was carefully looking at numbers for many countries: it was always possible to split CAGR for these 2 components. The video part was extremely consistent between countries. The subscriber part was 100% proportional to subscriber CAGR.
Everything else up to now was “marketing” to say it mildly.

Reminder: nothing in nature could grow indefinitely. The limit always exists. It is only a question of when.

PS: Of course, marketing people could draw you any traffic growth – it depends just on the marketing budget.

Eduard
From: Dave Taht [mailto:dave.taht at gmail.com]
Sent: Tuesday, May 9, 2023 11:41 PM
To: Vasilenko Eduard <vasilenko.eduard at huawei.com>
Cc: Phil Bedard <bedard.phil at gmail.com>; Etienne-Victor Depasquale <edepa at ieee.org>; NANOG <nanog at nanog.org>
Subject: Re: Routed optical networks

Up until this moment I was feeling that my take on the decline of traffic growth was somewhat isolated, in that I have long felt that we are nearing the top of the S curve of the data we humans can create and consume. About the only source of future traffic growth I can think of comes from getting more humans online, and that is a mere another doubling.

On the other hand, predictions such as 640k should be enough for everyone did not pan out.

On the gripping hand, there has been an explosion of LLM stuff of late, with enormous models being widely distributed in just the past month:

https://lwn.net/Articles/930939/

Could the AIs takeoff lead to a resumption of traffic growth? I still don´t think so...

On Thu, May 4, 2023 at 10:59 PM Vasilenko Eduard via NANOG <nanog at nanog.org<mailto:nanog at nanog.org>> wrote:
Disclaimer: Metaverse has not changed Metro traffic yet. Then …

I am puzzled when people talk about 400GE and Tbps in the Mero context.
For historical reasons, Metro is still about 2*2*10GE (one “2” for redundancy, another “2” for capacity) in the majority of cases worldwide.
How many BRASes serve more than 40000/1.5=27k users in the busy hour?
It means that 50GE is the best interface now for the majority of cases. 2*50GE=100Gbps is good room for growth.
Of course, exceptions could be. I know BRAS that handles 86k subscribers (do not recommend anybody to push the limits – it was so painful).

We have just 2 eyes and look at video content about 22h per week (on average). Our eyes do not permit us to see resolution better than particular for chosen distance (4k for typical TV, HD for smartphones, and so on). Color depth 10bits is enough for the majority, 12bits is sure enough for everybody. 120 frames/sec is enough for everybody. It would never change – it is our genetics.
Fortunately for Carriers, the traffic has a limit. You have probably seen that every year traffic growth % is decreasing. The Internet is stabilizing and approaching the plateau.
How much growth is still awaiting us? 1.5? 1.4? It needs separate research. The result would be tailored for whom would pay for the research.
IMHO: It is not mandatory that 100GE would become massive in the metro. (I know that 100GE is already massive in the DC CLOS)

Additionally, who would pay for this traffic growth? It also limits traffic at some point.
I hope it would happen after we would get our 22h/4k/12bit/120hz.

Now, you could argue that Metaverse would jump and multiply traffic by an additional 2x or 3x. Then 400GE may be needed.
Sorry, but it is speculation yet. It is not a trend like the current (declining) traffic growth.

Ed/
From: NANOG [mailto:nanog-bounces+vasilenko.eduard<mailto:nanog-bounces%2Bvasilenko.eduard>=huawei.com at nanog.org<mailto:huawei.com at nanog.org>] On Behalf Of Phil Bedard
Sent: Thursday, May 4, 2023 8:32 PM
To: Etienne-Victor Depasquale <edepa at ieee.org<mailto:edepa at ieee.org>>; NANOG <nanog at nanog.org<mailto:nanog at nanog.org>>
Subject: Re: Routed optical networks

It’s not necessarily metro specific although the metro networks could lend themselves to overall optimizations.

The adoption of ZR/ZR+ IPoWDM currently somewhat corresponds with your adoption of 400G since today they require a QDD port.   There are 100G QDD ports but that’s not all that popular yet.   Of course there is work to do something similar in QSFP28 if the power can be reduced to what is supported by an existing QSFP28 port in most devices.   In larger networks with higher speed requirements and moving to 400G with QDD, using the DCO optics for connecting routers is kind of a no-brainer vs. a traditional muxponder.   Whether that’s over a ROADM based optical network or not, especially at metro/regional distances.

There are very large deployments of IPoDWDM over passive DWDM or dark fiber for access and aggregation networks where the aggregate required bandwidth doesn’t exceed the capabilities of those optics.  It’s been done at 10G for many years.  With the advent of pluggable EDFA amplifiers, you can even build links up to 120km* (perfect dark fiber)  carrying tens of terabits of traffic without any additional active optical equipment.

It’s my personal opinion we aren’t to the days yet of where we can simply build an all packet network with no photonic switching that carries all services, but eventually (random # of years) it gets there for many networks.  There are also always going to be high performance applications for transponders where pluggable optics aren’t a good fit.

Carrying high speed private line/wavelength type services as well is a different topic than interconnecting IP devices.

Thanks,
Phil

From: NANOG <nanog-bounces+bedard.phil=gmail.com at nanog.org<mailto:nanog-bounces+bedard.phil=gmail.com at nanog.org>> on behalf of Etienne-Victor Depasquale via NANOG <nanog at nanog.org<mailto:nanog at nanog.org>>
Date: Monday, May 1, 2023 at 2:30 PM
To: NANOG <nanog at nanog.org<mailto:nanog at nanog.org>>
Subject: Routed optical networks
Hello folks,

Simple question: does "routed optical networks" have a clear meaning in the metro area context, or not?

Put differently: does it call to mind a well-defined stack of technologies in the control and data planes of metro-area networks?

I'm asking because I'm having some thoughts about the clarity of this term, in the process of carrying out a qualitative survey of the results of the metro-area networks survey.

Cheers,

Etienne

--
Ing. Etienne-Victor Depasquale
Assistant Lecturer
Department of Communications & Computer Engineering
Faculty of Information & Communication Technology
University of Malta
Web. https://www.um.edu.mt/profile/etiennedepasquale

--
Podcast: https://www.linkedin.com/feed/update/urn:li:activity:7058793910227111937/
Dave Täht CSO, LibreQos
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