How to even begin to diagnose/isolate ongoing speed issues?

After 5 years of trouble free service and no issues with our Zen 'Active' home broadband ADSL+ connection I am at a loss on how best to proceed investigating the sudden loss of consistent throughput and download speed that has blighted us over the last few months - so any advice would be gratefully received!

Our service consistently returned 3-4-5 mbps of usable speed for most of our time with Zen - but for the last 2 or 3 months has struggled to reach 1 mbps at most times.
During peak periods (evening) it hovers around 250-500 kbps..........rendering it terminally frustrating for anything but the most basic web-browsing.

Nothing has changed regarding our set-up domestically that I can fathom.
The PC is functioning as efficiently as ever and regularly virus checked, defragged and kept uncluttered and monitored for performance issues.

I have run regular daily speed tests (from a variety of sources) as well as various diagnostic apps that indicate nothing untoward.

Our mobile devices return similar low speed figures so am tempted to rule out a PC issue?
Very occasionally the speed test will return a useful speed of upwards of 3-4mbps which while not blistering, is acceptable for streaming, downloading and all the things we expect to be able to do - so suspect the WiFi router is still functioning appropriately?
Would it be worth hunting out an ethernet cable to check it further?

The router stat home-page returns a sync speed capability of 6-7 Mbps (I do not fully understand the noise margin figures however)
The Zen line data page (Bras Profile) gives the same (with the occasional short-lived dip)
BT's line checker gives a POTENTIAL speed for the line in the 2.5 to 5 mbps range but their speed test pretty much echoes the others (ie - 0.3mpbs or thereabouts at peak times)
Ping is good.
Upload is as expected.

These figures appear identical to how they appeared when our throughput was satisfactory over the years.

But for 90 percent of the time even the lowest quality streaming buffers constantly and some image heavy web-pages now don't even load or just timeout.

We are approx 1 copper wire mile from the local exchange.


It is my understanding that (most) ISPs will immediately blame BT who then in turn blame the customers hardware or pass the buck back to the ISP in a never ending circle. So can anything EVER be done? And if so.....where to begin?

I am reasonably computer savvy but the intricacies of how the internet works out in the wild are beyond me!!

One thing I HAVE noticed however is that the slower speeds have coincided with the completion of a big new housing estate locally and the main road-which presumably carries the copper - is undergoing major roadworks. But BT report no known line faults for our address.

Should I raise the issue with ZEN? Would they be able to pin-point or rule out any anomalies?

Thanks for bearing with me on this one.

Best

Ron

Edited by deleted (Mon 04-Nov-13 00:07:11)

I have read your post and it seems to me like contention, follow this advice and you won't go far wrong:

Familiarise yourself with the BTw speedtest domain logon and speedtest process. http://www.kitz.co.uk/adsl/btwspeedtest.htm

i.e., go and test this procedure now and make sure you can do it.

Familiarise yourself with plugging your router into the test socket on your BT master faceplate - do a bit of googling lots of info out there how to do it.

Connect your PC via ethernet cable to rule wireless issues out.

When you notice your connection going slow, immediately disconnect all devices apart from your PC. Log onto your router and check the line sync speed - if it has gone abnormally low you have a line issue, if not there is a contention issue of some sort -- hence keep reading: Do a speedtest on thinkbroadband using your PC. Note the slow speed down.

Immediately log onto the Btw speedtest domain and run a speedtest on the BT webpage. Get at least 3 test results.

Then plug the router into the test socket, get another 3 test results.

Screenshot all the results each time and save them as files on your PC.

Hopefully, these speedtest results will all be slow. This will be sufficient evidence to log a call with Zen and they will investigate from there. If you have the evidence I've described in my post you will cut out days/weeks of faffing about.

Edited by Pipexer (Sun 03-Nov-13 23:24:16)

Thanks for your kind response Pipexer.

I will look into using the BTw process you describe.............I just need to get my head round 'bypassing' the ISP (?) !

Most of my investigations and testing has been done with the router in the test socket already, but I have only just found my long lost monster ethernet cable so have yet to test the router with it.......that's a must-do I think.

At no point have I noticed the line sync speed dip at the same time as the slowdowns so - yes - my limited understanding leads me to suspect contention too. But I don't REALLY know what I am seeing when I look at the router stats.

How do contention issues get addressed? CAN they be? Or are we all just condemned to ever dwindling speed by BT/Openreach (who I presume hold all the cards here)? There are so many gaps in my knowledge so apologise for my naivety!

Thanks again.

R

Edited by deleted (Sun 03-Nov-13 23:50:15)

Yes contention issues will get addressed if they fall below the minimum by BT (and the speeds you quote are below the minimum). For now don't worry about that but basically get evidence.

-Use test socket
-Get line stats
-Get speedtest while logged into Zen
-Get speedtest when on BTw domain.

Definitely replace microfilter now as that will be the first thing they ask you to try replacing.

Sync speed dipping at time of slowdown is unusual as that would mean the line has dropped and THEN went slow, and then dropped again to go fast again... that doesn't seem as likely imho from your description. But I'm not saying its impossible.

Also post all the data on here just in the event it isn't contention we'll be able to tell you.

In reply to a post by Ron_Trousers:

After 5 years of trouble free service and no issues with our Zen 'Active' home broadband ADSL+ connection I am at a loss on how best to proceed investigating the sudden loss of consistent throughput and download speed that has blighted us over the last few months - so any advice would be gratefully received!

A good starting point for understanding the situation is to look at the 'View Line Data' option on the customer portal. Look for the line that starts "Your current line technology is". If what follows mentions LLU, your connection has been moved from BT Wholesale to the new Zen network, which is present in some 200 exchanges. There's a fuller explanation in Zen's forum.

If you are on the new Zen network, you should ignore any BT Wholesale specific advice you've been given. You may be experiencing some sort of compatibility issue between your DSL equipment and the Zen MSAN port you're now connected to, but there could equally be another issue.

If you are on the BT Wholesale network, the 'View Line Data' page will show a history of the synchronisation speed of your line.


Whichever network you're on, I'd try calling Zen support for help, because the logs and other information they have access to about your connection may throw light on this issue.

In reply to a post by Ron_Trousers:

The router stat home-page returns a sync speed capability of 6-7 Mbps (I do not fully understand the noise margin figures however)

Please post all the router stats when plugged into test socket, both when it's speedtesting slow and when it is reasonable, even if you don't understand them. We do!

@ Other posters: I am suspicious of the phrase 'sync speed capability'. It could mean Max Attainable Speed or it could be Actual Speed.

Can I come at this from a slightly different angle. Whilst this sounds on the surface to be contention, There are a number of other areas which could cause this type of behavior.
These may seem silly questions, but please bear with me there is logic behind the madness.

Are there any patterns to the performance you see, i.e it goes faster when there has been a period of dry weather, but as soon as it starts to rain you connection slows up ? Also do you ever experience connection drops or noise on the line when you use the phone.
Seeing these issues could point to a line fault, somewhere between you and the exchange, and when water gets on the line this causes noise, and the data transfer speeds to drop. However i would also expect your sync speed to be all over the place, and it already sounds to be much higher then the transfer rate.

Are there any times of the day when the lines works well, I'm thinking here of very early in the morning, before your neighbors get up. If the connection is always good early and slowly deteriorates during the day, then that defiantly points to contention. If this is not the case then this points away from contention.

I know this sounds really silly, but if none of the above match, and your router is a few years old this could be the issue as well, I've had an old netgear , which over a few weeks got slower and slower, until the PSU finally gave up. I would not suggest going and buying a new router as this is a long shot. but if you happen to have an old one and other filters then its worth a try.

All of the above should really be tested using a wired connection to the router and the router plugged into the master socket. (making sure no one has added additional circuits to the back of the master socket).

Maybe this would help atleast point you in the right direction.
Andrew

First of all....
Many MANY thanks to all those who have replied to me as a slightly mystified newbie. I did not expect this helpful response to such a vague query and it has already helped me see a little clearer what might be happening and given me a strategy to work through before raising the issue with ZEN.

@ XraySpex.......sorry - I don't what made me type 'capability' in reference to my sync-data! As far as I know the router status gives this as a 'real-time' figure. It varies very slightly from time to time-but always returns a figure between 6464 and 7300 Kb or thereabouts.

I don't have time this evening to do much in the way of testing......but here is a snapshot of my router stats at the present time (21.35hrs)

ADSL - Type - Interleave

STATUS - 'SHOWTIME' (I think this is Belkins little joke!)

DATA RATE Down:6464Kb
Up: 448Kb

NOISE MARGIN Down : 7
Up: 26

OUTPUT POWER (dBm) Down 123
Up 198

ATTENUATION (dB) Down 42
Up 21

(I'd love to know what the figures mean...................I think!)

Speed Test is giving me 898kbps at the present moment.


I have decided to keep a proper log of speeds over various times of day and signed up to the 'OOKLA' speed test site (for better or worse) where my test results can now be permanently recorded and exported to an 'Excel' file when required.

Interestingly ...... I recorded a speed of 5.5Mbps at about 2.30am last night
4.9Mps at 4.30pm this afternoon
and 0.93Mbps just half an hour later.

Upload speeds are nearly always about 380kbps regardless of how slow or fast the down speeds are.

It has stayed at less than 1Mbps since then which is pretty much par for the course. In fact......most evenings it runs below 500Kbps for long periods of time - but I shall log it carefully and see if a pattern emerges over time?


Andrew - Yes, there does seem to be a 'weather' aspect to this. I'll keep tabs on it.

My router IS 2 or 3 years old and is only 'G' (Belkin) type wireless, not 'N'...but the signal doesn't have far to travel and seems robust. It is plugged into the master socket as we speak.

I'll do some tests with my ethernet cable too as soon as I have time.

I have run a network SSID sniffing type app as well ....just in case my neighbours are leeching my signal! But they aren't...and we are on different channels as well as well as being securely locked down.

I'll report back with any exciting clues soon!

but.........

Thanks again one and all.

Best

R

Edited by deleted (Mon 04-Nov-13 22:25:09)

Thanks, they are just the figures I want.

In reply to a post by Ron_Trousers:

DATA RATE Down:6464Kb <- Speed is just right for your line length

NOISE MARGIN Down : 7 <- A tolerance or margin within which noise on line may rise before it affects your connection. Most ISPs set it to 6dB upon initial connection but it will vary a bit over time. So yours is OK.

ATTENUATION (dB) Down 42 <- A measure of your line length

(I'd love to know what the figures mean...................I think!)

Your connection to exchange is perfectly OK. Your throughput from it should be around 5.4 Meg. So, it does look like you are suffering from congestion during peak times. It might be useful to see your speedtests over ethernet, but I doubt whether you are being hampered by wireless as you do get good throughput off-peak and G-wireless is more than sufficient for your connection.

You are on the older ADSL Max technology which is prone to congestion with most ISPs. What exchange are you on? You might be better off on ADSL2+ if it is available there.

You Up throughput is exactly right for your connection.

In reply to a post by Ron_Trousers:

our Zen 'Active' home broadband ADSL+ connection

If that's meant to be 'ADSL2+', you are not on it but on ADSL1.

If your on a BT exchange you might be able to use this link to check if there is congestion.

http://usertools.plus.net/exchanges/

Hi,

From everything I've seen so far this sounds very much like contention. Can you PM me your username so I can take a look and see if this is something BTW are aware of already? Based on that result we can then advise on what's likely to be the best next course of action.

kind regards,
Phil.

Thanks all!

@arendall - here is the result of the 'PlusNet' exchange status check.........

Exchange Status Checker
Results: South Brent
Code: WWSBNT
County: Devon
Enabled: 30 Jan 2004
Market: 1
Mkt2014: A
green 20CN virtual paths: Green
There are currently no known 20CN VP capacity problems on your exchange. There may still be an exchange problem, however BT are not currently reporting that they are aware of it. Please contact Support if you are having speed problems, who can advise further.

Record last updated: 18 Oct 13

Thanks for the link


@SkyFire (Phil) I had no idea that these forums would be monitored by ZEN staff!! This seems service beyond the call of duty? Thankyou for your interest and I will PM you my details ASAP.

Best All

R

(I am learning a lot already)

Edited by deleted (Tue 05-Nov-13 13:01:04)

You can sign up on our site and also permanently record the speed tests and also expect them in a CSV file to excel.

Also as we show burst and average figures it makes it clearer if the speed is very variable. Some Ookla testers have a tendency to show only burst type speeds, others seem to be more like an average.

Wireless is something I have problems with at nights, and jumping to a 5GHz band helps or running a cable for when I need a real reliable connection.

In reply to a post by Ron_Trousers:

I'll do some tests with my ethernet cable too as soon as I have time.

That could be the beginning and end of the problem. You should NEVER rely on a wireless connection to do a speed test. Use a cable or don't bother.

Ron,
I take it the issue is now fixed? What was the cause ?
Andrew

Hi Andrew........thanks for coming back.

My speeds are still all over the place during peak times and I am monitoring them to establish a pattern of evidence before asking ZEN if anything can be done - but I am at least fairly sure now that my problem is a BT congestion/contention issue and less likely a problem with my hardware/or settings.

I have also just found out from the 'PlusNet' Exchange Checker that we are due to be enabled for some new protocol (21n or ADSL max-I can't quite recall the exact terminology!) some time in the new year (they keep moving the date forward!!) but whether this is a 'good thing' or will have any bearing on the line capacity I have no idea.

I'll come back to report soon.

Thanks.

r