Lower connection speeds recently

[#1]

Hi All,
I do not know what is the problem with my up-to-8mb connection.  A few months ago I used to get up to 4417 kb/s.  Not great but for my needs adequate.
Over the last couple of months connection speeds are getting worse and worse.  Over the weekends appear to be worse.  I checked my modem statistics and can see that over the last four days my connection speed has been reported as follows:
[tt]ADSL Link       Downstream Upstream
Connection Speed 3840 kbps 448 kbps
Line Attenuation   39 db   12.5 db
Noise Margin       6 db     24 db
Connection Speed 3840 kbps 448 kbps
Line Attenuation   39 db   12.5 db
Noise Margin       8 db     24 db
Connection Speed 4000 kbps 448 kbps
Line Attenuation   39 db   12.5 db
Noise Margin       7 db     22 db
Connection Speed 2976 kbps 448 kbps
Line Attenuation   38 db   12.5 db
Noise Margin       9 db     23 db[/tt]
The 4000kbps jump you see was achieved when I power cycled the modem.  The subsequent drop down to 2976kbps happened all on its own.  The stats do NOT show that the link to the exchange was lost, so I cannot readily explain why the reduction in speed.  Other than . . . it happened on Saturday morning (more people on line?) and the weather was rather wet on Friday night.
Any ideas?  How do I troubleshoot this one?
--
Regards,
Mick

[#2]

As you might already know, your connection speed to the internet depends on a lot of things. The length of your line, any breaks within the line, your master socket, any extensions you have, other items connected to your phnoe line and so on.
Looking at the details above, I have encountered this in the past when using a netgear router. Luckily I was only testing them to see what they were like in comparison to my D-Link router, but to be honest with you I stuck with my trusted D-Link.
Another factor is the noise margin. Looking at the read outs above your noise margin is rather low to stay connected at 3840, especially if these are readings from during the day as the noise margin seems to drop a little at night.
It could be worth checking to see if interleaving is turned on or not. If you use an extension for the router, why not try it in the master socket to see if this improves things (It did for me and I now sync at over 1500 higher than I did before).
Sorry if the reply appears confusing, but im suffering from something so am not feeling my normal self.
Regards,
Tom. (tomspcs)

[#3]

As per the above, I'd recommend testing with the ADSL equipment in the master socket to see if this does improve things. It might also be worth removing anything else plugged in to other phone sockets throughout the premises  to see if there's some source of interference there - it's essentially noise on the line that's causing these random changes in speed. Once you've unplugged everything try plugging it all back in one item at a time and see if there's anything in particular causing the drops (if it is something in your house).
Hope that helps,

[#4]

Thanks guys,
My master socket is in a star circuit (i.e. the master socket is on a spur).  Further more it is not of the NTE5 variety, but a plain LJU type master socket.  Does it still make any odds to connect the modem at the master socket (it is twice as far away from the entry point of the BT tepephone wire in the house than the current socket).
When I do my tests removing ADSL filters and telephones from the other sockets in the house, will the noise margin change immediately, or will I have to wait for while (how long)?  Is there a need to resync or do I leave the modem connected at all times?
Thanks again,
--
Regards,
Mick

[#5]

Hi,
Try it in the current socket with all the other items removed, and if there's no improvement try the master. It's better to eliminate as much as possible, including the internal wiring.
As for how long, or resyncing - the router should sync up as soon as it's in the socket, if you remove or add anything it would be wise to resync to see if there is any change in the noise levels on the line. The noise levels should change immediately but not be visible until after a resync.
Basically, resync after you change anything on the network.
Hope that helps,

[#6]

WOW! 
I removed everything off each face plate, filters, telephones, the lot.  Just left the fliter on which has the modem connected to it.  Then I resync'ed:[tt]
ADSL Link        Downstream  Upstream
Connection Speed 4128 kbps 448 kbps
Line Attenuation 39 db     12.5 db
Noise Margin     8 db      24 db
[/tt]
Given that it is night time, the neighbours have turned on their Christmas lights and it's raining, this is an impressive increase. 
However, I can still see low speeds during on-line speed tests.  www.speetest.net gives me just 2317kbps.  Is this going to improve to match the link speed?
It seems that I'm gonna be busy this Christmas rewiring the telephone sockets and installing a NTE5 master socket for my modem.
I wonder what it's going to jump up to if I were to also remove the orange bell wire . . .
Thanks for your advice!

[#7]

If you can maintain that sync speed for 3 days your IP Profile set by BT (and mirrored under High-speed broadband by PlusNet) should increase to 3500 which would give you a throughput around 3000kbps.
Testing on PlusNet's mybroadbandspeed tester helps to eliminate Internet influences external to PlusNet.

[#8]

Greetings,
It might be an idea to see if you can get yourself an ADSL Filtered Faceplate (as made by ADSLNation).  This can improve the level of stability on your line from a sync speed perspective.  I wouldn't expect you to see higher than the 4.1/4.2Mbps you're currently seeing, but it might help to stabilise things.
As mentioned, you generally need to see higher sync speeds for approxcimately 3 days before you see an improvement in your throughput speeds.

[#9]

I can vouch for James said about the faceplate. I bought myself one, forgot where fromt hough, and it works a treat.
One thing I have found though, which I will sort out at a later date, is that my stable rate is set to 3500 where as my sync is 5056....
IP profile for your line is - 3500 kbps
    DSL connection rate: 832 kbps(UP-STREAM)  5056 kbps(DOWN-STREAM)
    Actual IP throughput achieved during the test was - 3111 kbps
Ill sort it out later and have it refreshed as it should be 4500 in reality as I have been synced at 5056 for about 4 days now.
But yer, and ADSL Filtered faceplate is definately worth the investment.

[#10]

Quote from: Jameseh

[snip...] I wouldn't expect you to see higher than the 4.1/4.2Mbps you're currently seeing, but it might help to stabilise things.

I resynced early this morning and got in excess of 4.9Mbps which is as high as I ever remember it to be.  There is a pattern here which I have noticed.  Although the modem is connected to a quality filter (dongle) the telephones (x2) are connected to the cheaper 'T' shaped snapon type filters.  These seam to either gradually degrade (as it happened now) or to fail completely and bring down the connection with them (as it happened about a year ago).  The latter is a giveaway as to why things are wrong, but the former failure mode can catch you out.
Are the face plate intergrated filters fit & forget, or are they also expected to fail with time?
Meanwhile, thank you for all your help.  Hopefully I'll be browsing again at higher speeds soon.
@HSNetwork:  How will you sort out the difference between your IP profile (3500 kbps) and your DSL connection rate (5056 kbps)?  Is it stuck?
--
Regards,
Mick

[#11]

Quote

Are the face plate intergrated filters fit & forget, or are they also expected to fail with time?

Well, it's electronic equipment so over time it will deteriorate but this certainly shouldn't happen any time soon - the nte-2005 faceplate can be bought here though unfortunately I couldn't find any guarantee period specified.
Hope that helps,

[#12]

Quote from: MickKi

@HSNetwork:  How will you sort out the difference between your IP profile (3500 kbps) and your DSL connection rate (5056 kbps)?

Given Tom's history (he used to moderate these forums), I expect one of the Comms guys will spot it here and sort it for him - if not, its simply a case of raising a ticket asking for it to be actioned.

[#13]

This should be done by BT and will be picked up by our system as soon as it's actioned. If our profile doesn't match BTs line profile we can change that pretty rapidly, but unfortunately there's no easy way for us to update a profile on BTs systems.

[#14]

Still seeing rather low throughput speeds I decided to disconnect the bell wire.  Furthermore I bought a new ADSLNation filter and resynced.  I am now sitting comfortably at a stable link speed of 4690kbps for more than four days (115 hours).  Within a day or so my IP Profile increased from 2500-3000 to 4000 as shown in the test below.  Unfortunately, my download speeds continue to be low!
[tt]=========================
IP Profile: 4000
Connection rate: 448/4960
Actual IP throughput: 2252
=========================[/tt]
The above speedtest was run at 6 in the morning just to make sure that high contention was not the cause of the low speeds.  I have of course run speed tests at all times of the day and the throughput was always between 2200-2390.  I raised a ticket hoping that there's something that can be done to improve the actual IP throughput and I am told by Plusnet (Metronet) support that BT will just bounce the ticket back because 2252kbps is higher than what they will consider to constitute a fault on their infrastructure.  With the above IP profile and link rate I would expect a throughput of 3500+.  Less than 6 months ago I was getting 4700+ throughput speeds, so I am convinced that something is definitely wrong with the line.
Is there anything I can do about this?
--
Regards,
Mick

[#15]

Perhaps this is a good candidate for MTU/RWIN tweaking?
I'm certainly not the expert in that respect (peers over at spraxyt) but if exchange contention can be ruled out (and a 6am test is usually a good indicator) then that would be the next step that I'd try.
B.