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[cbdeakin]

Are there any VDSL modems that can do this?

Basically, I discovered that my VDSL2 line has 1-2% packet loss (I can see this in various applications like Google Stadia and other streaming services), and I'm fairly sure it's on the upstream part of the connection, which is not interleaved (the downstream is). It's enough to cause stuttering and input delays in the stream.

I realise this will seem strange to a few people on these forums, as many users (particularly gamers), seem to want to remove interleaving from their lines, but I think there are reasons why you might want it to be enabled on your line (particularly if G.INP is not an option). I think my line would be fine with interleaving enabled on the upstream, because latency is only 9-10ms to websites like bbc.co.uk.

My line has never had G.INP enabled, which I suspect would've helped a lot to reduce packet loss on the line (note - I've confirmed it's not my own network causing the packet loss and my PC has an ethernet connection to my router).

I'd appreciate any advice from the experts on this! I'm hoping that it's possible to force on interleaving with a telnet or SSH command on some modems. I suppose the other thing it would be useful to know, is how effective interleaving is at actually preventing packet loss on ADSL and VDSL lines.

[Reformed]

The stuttering on the streaming is downstream, Stadia's streaming doesn't care about upstream. Changing the upstream won't help you

[Alex Atkin UK]

I'd have to agree, upstream would cause input misses not stuttering.  Streaming services will be using UDP as you wan't no re-transmissions (from the server, re-transmission from the DSLAM is likely fast enough to be an improvement rather than detriment) on a live feed, but that means if you lose a few packets on the way it will likely skip that corrupt frame to avoid garbage on the screen.

[cbdeakin]

The interesting thing about this problem, is that if I set my upload speed to 500kbps, packet loss on the line is virtually 0.

I first noticed this when I ran this online networking test here:
https://www.measurementlab.net/p/ndt-ws.html

Which reported 0 packets lost and 0 bytes lost when limited to 500kbps upload. If I increased the upload bandwidth, it would start reporting lost bytes and sometimes retransmitted packets.

Then I ran these settings in Stadia and noticed the same thing, virtually no packet loss (with tons of latency).

[Reformed]

Why is Stadia using so much upstream, assuming there isn't something else up? Your kit only needs to be sending controller inputs?

Stadia only uses upstream for those inputs. The stream itself doesn't have any acknowledgement. How's your router?

[Alex Atkin UK]

Has to be said, I never had much luck with any streaming service and I tried Geforce Now, Stadia and Shadow.

Stadia particularly was annoying as it would work fine then suddenly the picture go all blocky and eventually lose the connection entirely.  Not been too keen on trying them since seeing as I have a beefy gaming PC, but there was one game that was Stadia exclusive I was enjoying until that started.

At the time I had Zen and Plusnet, both exhibited the same problem at the same time.  Doubt it was pfSense at fault as it had been working fine at first and still would periodically, just not long enough to get a full play session in.  I think I even tried over Three 4G with the same result.

[cbdeakin]

Why is Stadia using so much upstream, assuming there isn't something else up? Your kit only needs to be sending controller inputs?

Stadia only uses upstream for those inputs. The stream itself doesn't have any acknowledgement. How's your router?

Good point. I suppose it's the SQM (I'm using FQ_Codel, as it works much better on Stadia than que disciplines such as Cake), I've heard that can require a fair bit of upload (2mbps) for it to work well

[cbdeakin]

Has to be said, I never had much luck with any streaming service and I tried Geforce Now, Stadia and Shadow.

I strongly agree, certainly true in my case for both Geforce Now and Stadia. I'm fairly sure that Google have the best servers / infrastructure of any streaming service though. I assume your connection doesn't have G.INP enabled as you are on an ECI cabinet. It's hard to prove definitively, but I suspect that G.INP is probably helping to avoid this problem on a lot of FTTC lines (especially if the SNR is low, hence lower bit rate).

The best results I've had so far on Stadia, were with a per packet overhead of 256 and an upload limit of 2500kbps.

I had a chat with my ISP, they reckon interleaving wouldn't help, and might even increase the amount of lost packets (I suppose because of the chopping up and reassembling of packets that happens when interleaving is used).

[Alex Atkin UK]

I strongly agree, certainly true in my case for both Geforce Now and Stadia. I'm fairly sure that Google have the best servers / infrastructure of any streaming service though. I assume your connection doesn't have G.INP enabled as you are on an ECI cabinet. It's hard to prove definitively, but I suspect that G.INP is probably helping to avoid this problem on a lot of FTTC lines (especially if the SNR is low, hence lower bit rate).

Its possible it would be WAY better now as my errors are insanely low since I had my drop wire replaced.   I kinda doubt though that the problem was my end considering it was so severe and across three ISPs at the same time period.

[Chrysalis]

Signal errors dont increase or decrease with throughput normally, just would be more noticeable in the form of packet loss. 

So some things here I think need to be clearer.

Are we talking CRC errors on the upstream or just packet loss? The two are not the same thing.

When you see the packet loss what is the utilisation of the downstream and upstream in respect to the line capacity?

[j0hn]

Signal errors dont increase or decrease with throughput normally, just would be more noticeable in the form of packet loss. 

Exactly this.

You get the same/similar number of CRC/ES while downloading/uploading at full speed for 24 hours as you would having a modem synced but with no router connected, no PPP connection, no traffic being sent or received for 24 hours.

[cbdeakin]

Hi guys.

To clarify, the packet loss occurred on Stadia regardless of whether or not CRC errors / errored seconds were logged by the modem in the same time period.

Had another visit from 2 Openreach engineers earlier (I told my ISP about the packet loss, and asked them if they could do anything specifically at the exchange / FTTC cabinet). The engineers said the fault had been logged as 'low speed' when they turned up 

Anyway, they told me that the line is aluminium and so the impression I got was that there isn't much they can do, regarding the packet loss (they also mentioned that my line was connected to a 'distribution point' shared by 10 other lines).

They offered to enable interleaving on the upstream part of the connection (one of them said he sometimes used to enable interleaving on ADSL connections to reduce packet loss), so I will see what difference this makes. Latency has increased by 19ms (now around 29ms to bbc.co.uk). So, hopefully that won't harm things too much.

Aluminium cables apparently aren't twisted, so I assume this means they are prone to noise / interference.

So, aluminium line on a ECI cabinet, only the best for us  . Apparently the best you can get out of an aluminium line in our street is 60mbps downstream (which admittedly, isn't that bad).

[cbdeakin]

So, a little update:

Amazingly, interleaving appears to have solved my packet loss issue (0-0.001% reported in Google Stadia) on my crappy aluminium line

I will keep testing it. It looks like it was applied on both the downstream and upstream.

Might even be able to play at 4K Nope

[Alex Atkin UK]

Not really amazing given its what interleaving exists for.

[cbdeakin]

I'm getting around 20ms of additional latency, according to my line parameters (Delay value):