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Packet Loss Issues ADSL

markb5000
Grafter
Posts: 71
Thanks: 4
Registered: 13-10-2015

Packet Loss Issues ADSL

I'm having a lot of issues with Packet Loss which is making certain tasks like gaming very difficult. Typically i average on 1-5% Packet Loss although i have seen it go much higher, as high 50% PL.

I see it when i run PingPlotter to ping google for 24 hours or more, it happens at all times even in the early hours 2am-8am when nobody is on the internet.

I can also see it when i run the ThinkBroadband monitor which runs constantly pinging my router (the red shows the PL)

My Broadband Ping - My home broadbandWhat could be causing this? I had BT out of my property several times (5 if i remember correctly) before i moved to plusnet net and they couldnt find anything so its probably safe to say my end is perfect.

I suspect the issue to be at the exchange, possible congestion but i cant prove it. Is there anyway to check the exchange quality? FYI its the Rhydlewis (SWRLS) exchange.

Any other suggestions welcome.

17 REPLIES
Community Gaffer
Community Gaffer
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Registered: 05-04-2007

Re: Packet Loss Issues ADSL

The packet loss on the graph doesn't look too bad TBH, the spike around 2-3pm does match with a large amount of usage during that time.

 

You're not doing a huge amount of uploads, but try stopping anything using the upstream and see what the packet loss looks like then.

 

It's also worth trying a pathping: Open a command prompt (start -> run -> cmd -> pathping) and type pathping bbc.co.uk

If this post resolved your issue please click the 'This fixed my problem' button
 Chris Parr
 Plusnet Staff
markb5000
Grafter
Posts: 71
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Registered: 13-10-2015

Re: Packet Loss Issues ADSL

Chris,

With respect "not too bad" is not really acceptable. I dont know what was going on with the connection at 2-3pm but even so unless it was at full upstream capacity there really shouldnt be any Packet Loss.

Besides even when the connection is not in use (after midnight) its still happening.

I've had one day plotted out of the entire month where its had 0 packet loss so i know it is capable of being stable. This is how it should be every day but its rarely like this, maybe once a month if i'm lucky.

My Broadband Ping - My home broadband

I prefer pingplotter to pathping because of the graphs so i will post back when i get home with a screenshot but its basically the same as ThinkBroadband showing 1-5% packet loss with the occassional peak and odd day where its stable.

Also, is there anyway Plusnet can see the exchange quality graphs? I seem to recall when i was with you guys several years ago you could request graphs from the exchange showing the quality and any packet loss.

markb5000
Grafter
Posts: 71
Thanks: 4
Registered: 13-10-2015

Re: Packet Loss Issues ADSL

Well it seems since opening this thread the packet loss has sorted itself out. The last few days have shown almost perfect results with zero packet loss. Very strange indeed since i have been suffering from this issue for over 2 years Undecided.

My Broadband Ping - My home broadband

MattyC
Champion
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Registered: 10-04-2014

Re: Packet Loss Issues ADSL

We didn't make any further changes on your line. Might be worth monitoring.

ex-Plusnet staffer. Any posts after 28/07/2017 aren't on behalf of Plusnet
Superuser
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Re: Packet Loss Issues ADSL

The loss of ping packets at the level you report is not overly concerning; what is of greater concern is the periods of increased latency.  That more than PING packet loss is more likely to be the cause of your (first-world) gaming issues.

PING packets have a low priority and might well be dropped if there are end to end capacity issues.  The periodic increased latency should in the TBB BQM graphs are not untypical of congested BT exchanges.  Do these graphs look similar from day to day?

You've made no mention of the speed of your link - there is some possibility that the use you are making of your link is actually saturating its capacity.  Your internet service cannot run faster than your individual line will operate at nor the total capacity available on your exchange.

markb5000
Grafter
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Registered: 13-10-2015

Re: Packet Loss Issues ADSL

Well its been pretty good since i last posted with almost no packet loss just the random blip which is to be expected. I'm still monitoring. Whether its fixed for good or it will come back to haunt me only time will tell but i will keep you posted if it occurs again.

What i'm wondering is if the recent fibre rollout could have any impact, i'm on EOL so i dont benefit but my exchange has been officially fibre enabled so perhaps some of the congestion has been re-routed elsewhere.

FYI i'm on a 20CN ADSL service with the max premium addon, i get the full 8128kb/s sync speed which equates to 7.15mb/s but i have QoS in place to prevent saturation. Basically all my traffic falls in to groups and is prioritised based on what group they fall in to. ICMP and ping packets are amongst some of the ones i have priotised. I also have an upper limit in place that prevents my connection from going over 7mb/s (inbound) or 650kb/s (outbound) essentially preventing any saturation my end.

TBB BQM Graphs from last week, other than a few blips and what i assume is the modem resyncing its looking better

Monday 9th

My Broadband Ping - My home broadband

Tuesday 10th - average ping spiked at 6My Broadband Ping - My home broadband

Wedensday 11thMy Broadband Ping - My home broadband

Thursday 12thMy Broadband Ping - My home broadband

Friday 13thMy Broadband Ping - My home broadband

Saturday 14thMy Broadband Ping - My home broadband

Sunday 15thMy Broadband Ping - My home broadband

Superuser
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Re: Packet Loss Issues ADSL

Interesting!!!

QoS is not an area I understand well, however I would suggest that if you are restricting the DS rate you run the risk of data transmitted to you being dropped.  The PN & BT profiles are there to manage the rate that traffic is sent to your router - you have no need to manage that.

There is also a risk that your US QoS management might impact responses to in-bound data, resulting in the other end thinking the transmission failed.  Hopefully one of the router gurus might comment further on this.

markb5000
Grafter
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Registered: 13-10-2015

Re: Packet Loss Issues ADSL

I will never understand QoS fully but my understanding is that it only restricts the physical speed (throughput) with a 10% safety margin for any potential speed drops on the line. The sync speed between the router and exchange remains the same so to my knowledge the profiles that BT or PN use to manage traffic are managed all the same. Its only when the traffic gets to the router that the QoS kicks in and by then those BT or PN profiles are no longer applied since the traffic has already reached its end destination.

I'm no expert on the matter though so would be great to get another opinion.

All i can say is without QoS my internet becomes a complete shambles, all traffic is first in first out and it creates a bottleneck. In this day and age even something as simple as opening a web page can saturate the 7mb/s. With QoS off i have extreme jitter since my ping will begin at 20ms and quickly spike up to 200ms or worse case 2000ms, constantly going up and down, you can imagine what effect that has on SIP, VOIP and gaming.

With QoS enabled the magic happens, i can be browsing or watching youtube and regardless of what is happening on the network my ping will remain at a constant 20ms only very occassionaly spiking in to the 120ms-140ms range, which i'm told is unavoidable for copper lines. The QoS essentially prevents any bottlenecks since large lower classed packets/traffic gets delayed at the bottom, allowing the prioritised traffic exclusive first in first out. The connection can still be saturated if enough is happening, although it usually has to be something extremely heavy like P2P downloads, but even then QoS will kick in and prioritise those first priority packets only allowing the bottom packets out when there is room.

A lot of people will disregard QoS but i find it very interesting and helpful, particularly in my case. I cant see myself without it, atleast not until i get fibre which looks like its going to be some time off. Maybe a PN advisor could get me a date from BT Roll eyes.

Thanks

Superuser
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Re: Packet Loss Issues ADSL

Not really sure what you are trying to achieve here.  Ping traffic is considered to be low priority.  If you loose a few ping packets, so what?  The other stuff you mention is the important stuff, that's why a saturated link will (if left to its self) drop or deprioritise ping packets.

markb5000
Grafter
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Re: Packet Loss Issues ADSL

Ping may be low priority but VOIP and Gaming services rely on a good stable connection and low ping/jitter. With QoS on those services will always be prioritised even if it becomes saturated. With it off those services are just unuseable, to give an example using VOIP i will get the voices breaking in and out.
All i'm trying to achieve is a consistantly stable connection, like the graphs in my last post. Those screens show my line is capable of minimum latency and packet loss but its usually not the case. Normal scenario would be constant spikes of 5-10% loss every 10 minutes or so like my first screen.
If it stays like the recent screens i will be happy but i've been facing this problem for 2 years, and from my experience problems like that dont just go away. Something must have changed at the exchange side, its never been this stable for more than 48 hours before.

Just to give an idea of what results i usually get here is an old trace from pingplotter, this is from when i was still with BT last year. If the issue repeats itself i will post back with a recent trace graph but fingers crossed.

https://bt.i.lithium.com/t5/image/serverpage/image-id/33265iA4BB23BFAF5D71D4/image-size/original?v=v2&px=-1

Community Veteran
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Re: Packet Loss Issues ADSL

Ping isn't low priority, actually it's given a high priority by Plusnet's traffic management, like VoIP and gaming are. Most people shouldn't need to set up anything special like QoS on their router to get fairly low and constant ping times while downloading at full speed, because Plusnet's traffic management prioritises the ping packets.

I'm not sure where the idea that pings are given a low priority has come from. If the ping packet from your computer is passing through your router, on its way to the Internet, and there's no QoS / prioritisation, it'll be treated the same as all other packets. Responses to traceroute probes aren't pings, they are ICMP Destination Unreachable messages, and routers might give a lower priority to the task of generating those responses than to their main task of routing packets in and out.

Superuser
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Re: Packet Loss Issues ADSL

@ejs,

Thanks for the clarification of terminology.  I guess that its sloppy to refer to ICMP messages (generated by ping a.b.c.d) as pings (and I believe used by the TBB BQM).  It was to those such messages I refereed to being low priority an possibly dropped.

markb5000
Grafter
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Registered: 13-10-2015

Re: Packet Loss Issues ADSL

Well it depends, from what i can gather PN can only manage traffic to the end point destination, the router. Once the router receives traffic at that point the traffic becomes first in and first out (like a water pipe). So when we talk about low priority its usually down to the router, which in most cases either ICMP is not prioritised or its fighting against the other traffic in the pipe so the packets end up delayed or lost. You are right though this can happen with all packets which is why when my connection is not working optimally i lose VOIP and Game packets aswell as ICMP.
I do agree that most people shouldn't need any form of QoS or traffic management, its all down to the speed and size of the pipe (more speed=bigger pipe) so bigger pipes dont need it. But when we are talking about my 700kb/s upload and 7mb/s download, this can easily get saturated just from web browsing so QoS can be extremely useful in keeping those important packets from dropping.
Anyway enough QoS talk Tongue i didnt want to turn this in to a QoS thread just wanted to explain my situation and why i use the QoS. If anyone reading this is on a slow connection and wants to try QoS out i suggest checking out the linkys tomato forums, there is a wealth of information on there, read it thoroughly. I personally use the advanced tomato (shibby based) firmware but all recent tomato variations have QoS.

Community Veteran
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Re: Packet Loss Issues ADSL

But there's 7Mb of bandwidth for things entering your router, and there might be 100Mb Ethernet bandwidth or 20Mb of usable wireless bandwidth for things leaving your router, so there should never be any need for there to be any delay for things leaving your router. The pipes out of your router are much bigger than the incoming pipe (for the download direction).