On Wed, Apr 22, 2020 at 4:48 PM Dave Taht <dave.taht@gmail.com> wrote:
On Wed, Apr 22, 2020 at 2:04 AM Luca Muscariello <muscariello@ieee.org> wrote:
>
>
>
> On Wed, Apr 22, 2020 at 12:44 AM Dave Taht <dave.taht@gmail.com> wrote:
>>
>> On Tue, Apr 21, 2020 at 3:33 PM Jonathan Morton <chromatix99@gmail.com> wrote:
>> >
>> > > On 22 Apr, 2020, at 1:25 am, Thibaut <hacks@slashdirt.org> wrote:
>> > >
>> > > My curiosity is piqued. Can you elaborate on this? What does free.fr do?
>> >
>> > They're a large French ISP.  They made their own CPE devices, and debloated both them and their network quite a while ago.  In that sense, at least, they're a model for others to follow - but few have.
>> >
>> >  - Jonathan Morton
>>
>> they are one of the few ISPs that insisted on getting full source code
>> to their DSL stack, and retained the chops to be able to modify it. I
>> really admire their revolution v6 product. First introduced in 2010,
>> it's been continuously updated, did ipv6 at the outset, got fq_codel
>> when it first came out, and they update the kernel regularly. All
>> kinds of great features on it, and ecn is enabled by default for those
>> also (things like samba). over 3 million boxes now I hear....
>>
>> with <1ms of delay in the dsl driver, they don't need to shape, they
>> just run at line rate using three tiers of DRR that look a lot like
>> cake. They shared their config with me, and before I lost heart for
>> future internet drafts, I'd stuck it here:
>>
>> https://github.com/dtaht/bufferbloat-rfcs/blob/master/home_gateway_queue_management/middle.mkd
>>
>> Occasionally they share some data with me. Sometimes I wish I lived in
>> paris just so I could have good internet! (their fiber offering is
>> reasonably buffered (not fq_codeled) and the wifi... maybe I can get
>> them to talk about what they did)
>>
>> When free.fr shipped fq_codel 2 months after we finalized it, I
>> figured the rest of the world was only months behind. How hard is it
>> to add 50 lines of BQL oriented code to a DSL firmware?
>>
>
> Free has been using SFQ since 2005 (if I remember well).
> They announced the wide deployment of SFQ in the free.fr newsgroup.
> Wi-Fi in the free.fr router was not as good though.

They're working on it. :)

> In Paris there is a lot of GPON now that is replacing DSL. But there is
> a nation-wide effort funded by local administrations to get fiber
> everywhere. There are small towns in the countryside with fiber.
> Public money has made, and is making that possible.
> There is still a little of Euro-DOCSIS, but frankly compared to fiber
> it has no chance to survive.

I am very, very happy for y'all. Fiber has always been the sanest
thing. Is there
a SPF+ gpon card yet I can plug into a convention open source router yet?

>
> I currently have 2Gbps/600Mbps access with orange.fr and free.fr has a subscription
> at 10Gbps GPON. I won't tell you the price because you may feel depressed
> compared to other countries where prices are much higher.

I'd emigrate!!!

> The challenge becomes to keep up with these link rates in software
> as there is a lot of hardware offloading.


I just meant that these routers tend to use HW offloading 
and kernel qdiscs may be bypassed.

 

At this point, I kind of buy the stanford sqrt(bdp) argument. All you
really need for gigE+ fiber access to work well
for most modern traffic is a fairly short fifo (say, 20ms). Any form
of FQ would help but be hardly noticible. I think
there needs to be work on the hop between the internet and the subscriber...

Web traffic is dominated by RTT above 40mbit (presently).
streaming video traffic - is no more than 20Mbit, and your occasional
big download is a dozen big streams that would
bounce off a short fifo well.
gbit access to the home is (admittedly glorious, wonderful!) overkill
for all present forms of traffic.

I'm pretty sure if I had gig fiber I could come up with a way to use
it up (exiting the cloud entirely comes to mind), but
lacking new applications that demand that much bandwidth...

I of course, would like to see lola ( https://lola.conts.it/ ) finally
work, and videoconferencing and game stream with high rates and faster
(even raw) encoding also has potential to reduce e2e latencies
enormously at that layer.

>
> As soon as 802.11ax becomes the norm, software scheduling will become
> a challenge.

Do you mean in fiber or wireless? wireless is really problematic at ANY speed.

I meant that software scheduling becomes a challenge for the same
reason as above. Increase in total throughput of the box
will call for hardware offloading and kernel qdisc may be bypassed.

It is not a challenge per se, it is a challenge because traffic
may not be managed by the kernel.


 

at gfiber, the buffering moved to the wifi, and there are other
problems that really impact achievable bandwidth. When I was last in
paris, I could "hear" 300+ access points from my apt, and could only
get 100-200kbit per second out of the wireless n ap I had, unless I
cheated and stuck my traffic in the VI queue. A friend of mine there,
couldn't even get wifi across the room! Beacons ate into a lot of the
available
bandwidth. Since 5ghz (and soon 6ghz - is 6E a thing in france) is
shorter range I'm hoping that's got better, but with
802.11ac and ax peeing on half the wifi spectrum by default, I imagine
achievable rates in high density locations with many APs will be very
low... and very jittery... and thus still require good ATF, fq, and
aqm technologies.

I have high hopes for OFDMA and DU but thus far haven't found an AP
doing it. I'm not sure what to do about the beaconing problem except
offer a free tradein to all my neighbors still emitting G style
frames....

And in looking over some preliminary code for the mt76 ax chip, I
worry about both bad design of the firmware, and
insufficient resources on-chip to manage well.

How is the 5G rollout going in france?

Good question. I've just seen a speed test at Gbps on a phone
which can drain your battery in less than 5 minutes. Amazing tech!

 

I recently learned that much of japan is... wait for it... wimax.

>
> Luca



--
Make Music, Not War

Dave Täht
CTO, TekLibre, LLC
http://www.teklibre.com
Tel: 1-831-435-0729