Constant High Latency Spikes; Frequent Dropped Connection

[#1]

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@Mustrum wrote:

The congestion is either on your home LAN, or on the equipment in the exchange

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Sigh !

No, congestion occurs at the slowest link in the data chain,  on xDSL connections, this will always be at the modem.

That is why it is essential to apply QoS BEFORE data reaches the modem, so that latency is correctly managed.

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[#2]

You can sigh all you like, but the away graph tells a different story. 

[#3]

So this is the away graph in question -

and below is the explanation from the ThinkBroadband BQM FAQ -

[#4]

I used to have an ADSL (not ADSL2+) connection with a low upload, and I never had a graph with latency as bad as the away graph. I may be that I was using a more competent router, but the amount of traffic generated by the BQM isn't enough to swamp the upload unless other traffic is present too.

The TBB info was written some years ago (the 585 is ~14 years old) - most routers are much better than they were then, so I wouldn't expect any relatively modern router to produce a graph that bad when the connection is quiescent.

[#5]

I'd be seriously concerned about either of those two graphs.

As @Mustrum commented :  "The congestion is either on your home LAN, or on the equipment in the exchange"

The router not only moves traffic internal to external, and external to internal, but also internal to internal.

 Gven the very low internet speed any traffic is going to affect the graph even a simple camera writing to a storage device. The ICMP reply is going to be delayed and show as busy................

[#6]

@danielw 

Can you confirm the target device for BQM, is it a router or something else.

I have found for accurate results you should really use the router or a wired DMZ device. The Hub Two can be enabled for ICMP setting found in Advanced Settings >Firewall >Configuration.

[#7]

So starting with these assumptions -

• From the modem stats, the physical DSL connection is probably OK
• From the 'away' graph there is no packet loss (red), so again the physical DSL connection is probably OK
• From the 'away' graph there are no blue areas - which might have indicated background uploading such as BitTorrent etc
• From the modem stats, the DSL upload sync speed is only 1269 Kbps which is barely adequate for modern internet use
• From the 'AtHome' graph, the significant blue areas show that the modem is frequently overwhelming the upload path
• From the 'AtHome' graph, when the connection is busy there are periods of significant packet loss

Given that @Mustrum seems to be suggesting that QoS isn't the solution for @danielw ,

What other solution do you suggest @danielw  does next - that won't need re-tweaking the next time a new device is added ?

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[#8]

@Dan_the_Van  the router being used isn't a Plusnet hub, it's a UniFi Gateway Max

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[#9]

@Anunnaki 

I can read thank you, I was just pointing out where the setting is with a hub two.

Be nice to see the answer to the question of what the BQM target device is a wireless device could add latency to the test result

[#10]

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@Champnet wrote:

As @Mustrum commented :  "The congestion is either on your home LAN, or on the equipment in the exchange"

The router not only moves traffic internal to external, and external to internal, but also internal to internal.

Given that @danielw  is using commercial grade networking kit, and a router with 2.5Gb ethernet ports and 1.5Gbps firewall/IDS/IPS throughput capability -

    DrayTek Vigor 167 modem -> UniFi Gateway Max -> UniFi switch -> UniFi wifi access points

... where are you seeing a LAN 'congestion' bottleneck occurring in that setup ?

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[#11]

HI all, thanks for the help and further diagnostic questions so far!!

I've tried various setups, all with the significant latency shown on the BQM and extremely slow loading of pages / inability to stream videos.
1) Plusnet Hub 2 in modem-mode using PPPoE with Unifi Gateway Max (BQM hitting the Plusnet Hub)
2) Plusnet Hub 2 in router mode, with Unifi Gateway Max (BQM hitting the Unifi Gateway Max)
3) Draytek Vigor 167 in modem-mode using PPPoE with Unifi Gateway Max (BQM hitting the Unifi Gateway Max)
(have not yet tried Draytek in router mode)

Overnight at the request of posters here I tried leaving the Plusnet Hub 2 in router mode; set up to respond to BQM pings; nobody connecting to Plusnet wifi; NOT connected to my Unifi Gateway Max i.e. completely and absolutely unused by anything - no devices know about the Plusnet wifi connection except my phone (which was not connected to it other than to test that it was indeed working - then disconnected)

 Massive red patch is when I was using the Draytek instead - not relevant
A few hours of blue and yellow spikes is when I had the Plusnet plugged into Unifi Gateway Max and using it from VMWare remote log in to work
Overnight test as described above
First thing in the morning, plug back into Unifi Gateway Max, immediately see latency spikes

So - i think this shows that the problem is coming from / caused by something within my network, or at the very least the Unifi Gateway Max itself!?!?


(I have not yet tried to Smart Queue QoS suggested by @Anunnaki so that I could try this 'unused' test but will do that tomorrow/Friday - won't be home long enough to fiddle)

[#12]

@danielw  good work with your diagnostics ! - that is consistent with what you've described previously.

As your issue is mostly due to you being a long distance from your FTTC cabinet, and the corresponding low upload sync speed,  I'm wondering if there is anything you can do to improve your internal landline phone and modem wiring to increase your DSL speeds ?.

What does the BTW Broadband Availability Checker  show for your expected high and low values for -

• VDSL Range A (clean)
• VDSL Range A (impacted)

Then regarding your internal house wiring -

1. Does your landline Master Socket have a filtered faceplate ?
2. Is your modem plugged in to your master socket or an extension socket ?
3. What length is your modem's DSL cable, or total cable length between modem and Master Socket ?
4. Do you have any analogue telephone(s) connected ?
5. If you unscrew the Master Socket faceplate, is there any attached internal phone extension wiring ?

[#13]

@danielw   From your previous post "So - i think this shows that the problem is coming from / caused by something within my network, or at the very least the Unifi Gateway Max itself!?!"

Yes, and the point I was trying to make last night with the Away graph. 

However, you also mention you are on a 23Mb line, min 16Mb, yet you modem only shows 13, so this also needs investigating. A good starting point would be the BTW DSL checker and hearing the results about your internal phone wiring.

[#14]

Thanks @Anunnaki and @Mustrum 

Phone wiring:

• Does your landline Master Socket have a filtered faceplate ? No, i am using the spliter/filter dongle
• Is your modem plugged in to your master socket or an extension socket ? Master
• What length is your modem's DSL cable, or total cable length between modem and Master Socket ? 5 meters; however  I had the same issues when using the cable that came with the Plusnet Hub 2 so 1m? 2m?
• Do you have any analogue telephone(s) connected ? No - no telephones at all
• If you unscrew the Master Socket faceplate, is there any attached internal phone extension wiring ? What would I be looking for here? The faceplate pulls off and as a "phone plug" on it that plugs into the rest of the master socket. What would "internal phone extension wiring" look like? Do you mean where something branches off the cable to the master socket?
  
  

Everything is fairly old and janky in the house - we've just moved in and it's a project. I can see where the phone wire traces down the external wall and into the property; then there is some form of brown (junction?) box, phone wire comes out of that then to the master socket. I have not investigated the brown box yet.



BT Wholesale checker:
This needs phone number - don't have one, got a broadband-only contract
Or "Access Line ID" or "UPRN" - where do I get these? I haven't been able to find these in Plusnet account details. These weren't given to me when I contacted Plusnet about the latency either.


(ADSL is new to me - in my previous two places we had Virgin cable so a different ballgame)



On speeds - with the Plusnet Hub 2 i have only ever achieved speeds of 4-5mbs (maybe 6 or 7 if I was lucky). This is consistent in modem router; router mode; and unattached to my Unifi set-up.
With the Draytek, I can get  7mbps, maybe 11mbps 

Upload is always 0.9mbps - 1.1mbps

[#15]

From experience I seem to remember the slower the internet speed the more exaggerated the graph so what you see may just be the ICMP requests. Difficult to prove unless you’ve an alternative monitor…….

As  @Mustrum suggests it’s worth going back to Plusnet and politely request a line re-check.