Issues with bufferbloat on HH6/latency spikes when downloading, etc.

[nsz]

Hello all,

I (along with my family) have been experiencing issues with our internet for a few weeks now. On the 21st March we upgraded from Infinity's 30GB capped package to the Unlimited Infinity package (as house went from 1 occupant to 5).  Previous to this, I thought BT were throttling us for going so far past our data cap... however, the issue has persisted through the upgrade.

I have been on the phone to BT multiple times to little avail - tests run on their end indicated "no issues", though since we're still in the 10-day "adjustment" period, further checks will be inconclusive until those 10 days are up. We also have an engineer coming here on Monday.

My ICSI Netalyzr results are here. My HH6 has a wired ethernet connection with my computer and our YouView box - all WiFi devices/downloads/uploads were kept to a minimum whilst running the test.

I have also been keeping an eye on latency with PingPlotter for the last few days and (apart from the obvious visual lag), videogames and downloads regularly climb to 500ms+ latency (max. latency I have seen was around 2000ms) and will only subside once downloads/streams are stopped or games are closed. The same occurs if someone attempts to watch Netflix on WiFi via laptop.

We have no issues with speed (downstream 12Mbps min., upstream 1Mbps min.). I would expect our speeds to be enough for 1 computer, 1 laptop, and a few phones being used a reasonable amount at the same time. We had the same speeds in our old house using the HH4 with no huge latency issues. I swapped out our HH6 for our old HH4 to test if the problem still persisted, which it did, though to a slightly lesser extent.

I've also looked through any setting I could find within the HH6. Our firmware version is v0.09.05.11160-BT and was last updated 08/01/18 - is this the most recent update? Furthermore, our Event Log shows near-constant Multicast stream spam between our Galaxy S8 phone and our YouView box, though I doubt this has any impact on our connectivity as unplugging the YouView box and attempting to download a file yields the same latency spikes as always.

Technical log information is below:

This is a list of your BT Smart Hub settings and current statistics.

Product name:Smart Hub

Serial number:+088047+1650000415

Firmware version:v0.09.05.11160-BT

Firmware updated:Mon Jan 8 14:22:20 2018

Board version:01

DSL uptime:0 days,19 Hours26 Mins43 Secs

Data rate:1.141 Mbps / 13.095 Mbps

Maximum data rate:1.141 Mbps / 15.244 Mbps

Noise margin:5.6 / 8.3

Line attenuation:13.8 / 32.5

Signal attenuation:13.8 / 30.6

Data sent / received:298.0 MB / 3.4 GB

Broadband username:bthomehub@btbroadband.com

BT Wi-fi:Activated

2.4 GHz wireless network name:BTHub6-FPH9

2.4 GHz wireless channel:Automatic (Smart Wireless)

5 GHz wireless network name:BTHub6-FPH9-5

5 GHz wireless channel:Automatic (Smart Wireless)

Wireless security:WPA2

Wireless mode:Mode 1

Firewall:Default

MAC address:E4:3E:D7:FE:95:D9

Software variant:-

Boot loader:0.1.6-BT (Fri Sep 9 10:05:09 2016)

As advised in other forum posts, I have turned off Smart Setup and split our WiFi bands to minimise issues caused by the router. I also factory reset the HH6 around 24hrs ago to see if that'd fix the issues.

Is this normal? Is this something that'll just "clear up", or is it a bufferbloat issue with the Hub/its firmware? I am not against the idea of buying a replacement router/modem, but it's not like we're usually an exceptionally high amount of bandwidth - issues occur even when downloading files throttled to just 512kb/s.

Thanks in advance.

EDIT: Here are some of the results I was getting on PingPlotter whilst tracerouting to google.co.uk. 

[imjolly]

cann you enter your phone number and post results remember to delete number http://dslchecker.bt.com/adsl/adslchecker.welcome

you are a long way from your street cabinet hence the conenction speed is only 13mb which may be the problem if 5 people are trying to use the internat at the same time for more than just surfing

[Keith_Beddoe]

---

@nsz wrote:

Hello all,

Furthermore, our Event Log shows near-constant Multicast stream spam between our Galaxy S8 phone and our YouView box, though I doubt this has any impact on ou

Please see https://community.bt.com/t5/Home-setup-Wi-Fi-network/Constant-IGMP-traffic/m-p/1795451#M146320

[nsz]

@imjolly, here are my DSLChecker results.

@Keith_Beddoe, as for the IGMP traffic via the YouView box:

"If your BT YouView box is connected directly to the BT Home Hub the extra traffic that is being used in the latest software release will not affect anything else in your network..."

Our YouView box is connected directly into the HH6, yet one of the IPs initiating the Multicast stream and interfacing with the YouView box is a Galaxy S8 phone. Could an app on the phone be causing this? Within "My Network", the Galaxy S8 in particular seems to have an abnormally high amount of uploads, a total of 320MB more than my own computer over the same short (2-day) timeframe.

Also, do you still recommend the TP-Link Modem/Router covered on your Forumhelp site? Would changing router to another with QoS alleviate these issues?

I was running PingPlotter at around 5am this morning whilst playing a game (its upload was capped to 250kb/s) and although it would run with no issues for around 20-30 minutes, I suddenly found myself spiking to ~2500ms latency (5:25am). I watched my ping for a while after leaving the game but it didn't seem to settle at all. I closed all applications on my computer that "could" affect my connection and even restarted my computer (5:29am) to no avail before eventually going to bed.

If nothing changes I'll update after the engineer comes on Monday. For some reason I feel like it's a HH6/wiring/socket issue though maybe we are just too far from the cabinet.

[imjolly]

The dslchecker give speed estimate of 24/15mb and you are currently just below minimum Have you tried connecting to the test socket with a filter to see if that improves your connection speed more in to your estimated range

[nsz]

The room I currently use as a bedroom used to be an office and I believe the master socket was changed to this room from the hallway at some point in the past. The master socket already has two sockets (ADSL/Phone) and has "ADSL V1.0" on the faceplate itself. It's next to a socket labelled "Fax".

Unscrewing the master socket's faceplate and plugging another filter into the test socket doesn't appear to have an impact on the DSLChecker results, nor the stability of our internet itself. I have a feeling that the wiring inside the socket (or maybe throughout our house in general) might be pretty old though so I wouldn't be surprised if some issues were found with it. I don't know the last time this place had a once-over to check for faults or anything.

[imjolly]

If you used test socket did you check the extension sockets to make sure there is no dial tone at any socket. If there is a dial tone then there's is a problem with the wiring

[nsz]

I'm not sure what you mean. The only thing actually plugged into our master socket is the ethernet cable to the HH6. We have a few additional sockets for phone lines around the house and I'd assume all of them emit a dial tone because all of them work.

[imjolly]

That is what you would expect but if you connect to the test socket with a filter and recheck the sockets then they now should not have a dial tone.  If any have a tone then there is a problem with your wiring which will have an adverse affect in your broadband

[peaslaker · Accepted solution]

Bufferbloat is seldom caused by SNR margins or anything else happening on your line.

All connections have a capacity.  When that capacity is exceeded, if the devices default to a buffering behaviour you will get bufferbloat.  Ironically, devices with small buffers are better if no QoS is applied.

QoS is the only way to fundamentally resolve bufferbloat situations.  QoS implementations vary wildly.  HomeHub implementations have a tradition of being hidden or non-existent.  Whether they exist or not doesn't tell you anything about the quality of implementation.  The fact is they are not front  and centre in getting your setup bloat-free and that is a vendor/industry choice that happily tips the consumer towards costly upgrades.

In many ways, a 17Mbps ADSL2 line with proper QoS is better than a FTTC Infinity connection with no QoS... (although having more bandwidth can reduce the number of times the network load triggers a buffering situation, the situation is still severe when it does occur).

There are two areas where buffering can typically be an issue:

1.  Internet uplink

2. Wifi

You can have really debilitating buffering happening in your wifi, especially if you have any form of extenders.  Even fashionable mesh products suffer from this when they have wireless backhaul.

If you are testing on a wired connection, direct to your router you can eliminate Wifi buffering from your testing.  If that testing (http://dslreports.com/speedtest) indicates bufferbloat (without QoS, it will), then you've got to work out what QoS can be applied.

Hint.  The HH6 does not do QoS in any sensible form.  Seek alternatives.