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Old chesnut-speed

Soddinghell
Newbie
Posts: 4
Registered: ‎26-08-2007

Old chesnut-speed

Hello
I was wondering if anyone had any ideas about this;

ADSL Link Downstream Upstream
Connection Speed 352 kbps 448 kbps
Line Attenuation 54 db 15.5 db
Noise Margin 0 db 18 db
This has been my regular speed since I moved house some 8 weeks ago.
For you PN guys I have a current ticket open (22676670) but you seem to be running out of ideas!
Recently there was a blip when I was about to start checking as directed and this happened;
done nothing, about to start testing
System Up Time 12:44:09
Port Status TxPkts RxPkts Collisions Tx B/s Rx B/s Up Time
WAN PPPoA 15556 23086 0 43 557 12:43:41
LAN 10M/100M 19971 12239 0 506 31 12:44:04
WLAN 11M/54M 5680 5066 0 76 22 12:43:53
ADSL Link Downstream Upstream
Connection Speed 960 kbps 448 kbps
Line Attenuation 55 db 15.5 db
Noise Margin 8 db 19 db
29/8/07

Test1 comprises of Best Effort Test:  -provides background information.
    IP profile for your line is - 1000 kbps
    DSL connection rate: 448 kbps(UP-STREAM)  3200 kbps(DOWN-STREAM)
    Actual IP throughput achieved during the test was - 909 kbps

-----------------------------------------------------------------------------------------
unpluged every thing, different filter
Port  Status  TxPkts  RxPkts  Collisions  Tx B/s  Rx B/s  Up Time
WAN PPPoA 431608 648200 0 249 10697 23:58:54
LAN 10M/100M 630261 333763 0 10651 275 24:00:14
WLAN 11M/54M 887857 966594 0 10114 9867 24:00:03
ADSL Link Downstream Upstream
Connection Speed 928 kbps 448 kbps
Line Attenuation 55 db 15.5 db
Noise Margin 0 db 18 db
--------------------------------------------------------------------------------------------
2 days later
Test1 comprises of Best Effort Test:  -provides background information.
    IP profile for your line is - 750 kbps
    DSL connection rate: 448 kbps(UP-STREAM)  544 kbps(DOWN-STREAM)
    Actual IP throughput achieved during the test was - 433 kbps
So rebooted,
Port  Status  TxPkts  RxPkts  Collisions  Tx B/s  Rx B/s  Up Time
WAN PPPoA 16 15 0 4 11 00:03:49
LAN 10M/100M 817 567 0 790 170 00:07:16
WLAN 11M/54M 97 98 0 62 32 00:07:05
ADSL Link Downstream Upstream
Connection Speed 352 kbps 448 kbps
Line Attenuation 54 db 15.5 db
Noise Margin 6 db 18 db
I have run TCPoptimiser several times and and followed the link in another topic to achieve this ( if the link works);
http://www.dslreports.com/tweakr/block:1233bf0?service=dsl&speed=8000&os=winXP&via=pppoA
I have tried so many things advised by PN and in different topics that I think I am going in circles. (At least I have had a chukkle at the complaints of a lack an 8 meg connection speed.)
Oh and before I moved I had a stable 5.5-6 meg connection so this is a really big step backwards for me.
I know you must be fed up with speed questions but any help would be appreciated.
Cheers.
Ps. I'm a bit noobish to this so please use understandable language Grin
8 REPLIES
Community Veteran
Posts: 1,576
Thanks: 3
Registered: ‎13-04-2007

Re: Old chesnut-speed

You dont tell us what you are using ie a modem, router and what the model is.
Messing with setting can be dangerous if you dont know what you are doing. If you have a router the settings arnt the problem as the connections isnt there with the exchange so it wont help.
Have you done the standard things like plug into the master socket test socket with nothing else connected, tried other filters etc.
Could you beg borrow or steal a router to see if a new device makes any difference? 
Superuser
Superuser
Posts: 9,925
Thanks: 1,265
Fixes: 71
Registered: ‎06-04-2007

Re: Old chesnut-speed

The problem seems related to downstream line noise which affects noise margin.  Noise margins below 6dB are bad news and zero is very bad news.  Until whatever is causing that is identified and eliminated there is no point in tweaking settings.  Doing those will not cure this problem.
With attenuation of 54dB syncs at around 3000kbps should be achievable, as one of the BT speedtester results you posted confirms.  Clearly something is reducing noise margin so that mostly you don't get near that.  The questions mentioned by samuria are the first steps in trying to identify the cause of that.
David
Soddinghell
Newbie
Posts: 4
Registered: ‎26-08-2007

Re: Old chesnut-speed

hello
I'm using a netgear DG834G router and I havent changed anything, just run the checks.
The 2nd set of readings was before I did the "unplug, new filter" etc checks(althuogh the speed then was 3 times the norm) and the 3rd set of readings is with everything unpluged, a new filter etc and they are basicly the same.
I'm plugged into the master socket.
I appreciate what you say about noise but I dont know what causes it.I will try another router as PN are arranging a visit from BT next week and I want to check everything first.
Thanks for your help.
Community Veteran
Posts: 1,576
Thanks: 3
Registered: ‎13-04-2007

Re: Old chesnut-speed

The noise seems to go from 6 db which should just about work down to 0 can you keep checking and see if this is time related which may give a clue to the cause.
The old get a small portable radio tune it off any station so there is a faint hiss and walk about near the router, phone pc and see if you get any noise. This often shows up the problem. It could be TV, games console, DEC phone, microwave, SKY wiring near the line.
You say you are plugged into the master socket but have you removed the 2 screws and plugged in to the test socket which disconnects all extensions?  Make sure you have no phones on while you test then watch to see if anything happens when you put the phone back in
Soddinghell
Newbie
Posts: 4
Registered: ‎26-08-2007

Re: Old chesnut-speed

Hello,
BT came today and before he did anything my connection speed was  3552kbps, which is 10 times normal and 3 times faster than  its ever been.
He did some speed tests at PN, bt and speedtest.net and all showed a throuhput speed of 340 kbps. He said it was a server problem, fitted a filtered face plate and left.
Over the last half hour the router is showing from this
ADSL Link Downstream Upstream
Connection Speed 3552 kbps 448 kbps
Line Attenuation 56 db 15.5 db
Noise Margin 0 db 19 db
to this
ADSL Link Downstream Upstream
Connection Speed 3552 kbps 448 kbps
Line Attenuation 56 db 15.5 db
Noise Margin 2147483646 db 19 db
but seems to be around 2-3 db the most.
Now assuming the servers are not at fault, any ideas on the slow throughput speed.
And can you explain why 0db noise is bad.
Thanks
Superuser
Superuser
Posts: 9,925
Thanks: 1,265
Fixes: 71
Registered: ‎06-04-2007

Re: Old chesnut-speed

I expect the low throughput speed would be due to your IP profile (mirrored within High-speed Broadband on the PlusNet portal) being 500kbps because of syncs below 1152kbps in the last 3 days.
0dB noise margin (and the huge number is actually -2dB but mis-reported because negative numbers shouldn't happen) is bad because it is noise *margin* and not *noise*.  That means line noise is at the same level as the useful signal, like trying to hold a conversation in a very noisy environment.  There would be a lot of "pardons" and "can you repeat thats", so transferring a message (data) takes longer (reduced throughput).
In fact modems generally give up trying (lose sync) when noise margin falls much below 6dB, with sync regained at a lower speed to reestablish an adequate noise margin.  Analogy - speaking more slowly in a noisy environment can improve first-time understanding.
When BT were there with the modem synced at 3552kbps what noise margins did you have then?
David
dougrice
Rising Star
Posts: 217
Thanks: 1
Fixes: 2
Registered: ‎06-08-2007

Re: Old chesnut-speed

When I had the  Bell wire ( pins 3 or 4 )  connected at my master socket It trashed my MaxDSL connection.
I disconnected it at the Master socket and my MaxDSL is MUCH MUCH MUCH better!.
My master socket as wired on my 1991 houseconnected the B wire to the bell wire via the 1u8F capacitor. This is in the removable bit of the NTE5 master socket. All six wires were being sent to the extensions in the house. Now only the Blue White wires are connected to pins 2 & 5.
My Line used to get 1M before MaxDSL.
I was MaxDSL'd and the Down Stream speed was about 3600K, but the speed tests have been 400K and down to 136K and really bad after getting back off holiday.
After I disconnected the bell wire at the master socket, my speed went up. Last night I got 5M download!!!!!!!
After 2 years of Support desk questions, I spent a few hours testing every filter in my house direct to the NTE5 master socket measuring with my Solwise 715 ADSL router. It allows you to do a command ADSL SHOW CHANNELS.
My ADSL Modem is normally at the other end of the phone extension wiring in my Computer den bedroom, with three phones spured off with filters at their sockets. This configuration must be typical but is not an option in Help pages.
Last Sunday, I established that the old Solwise microfilters only used two pins on the BT plug. They use pin 2& 5. I thought, Why do I need to connect the bell wire on Pin 3 ( or 4 )? When I disconnected it my download speed went up to what I got when directly plugged into the master socket.

So at the Master socket the house extension wire only connects the blueWhite & WhiteBlue wires to pins 2&5.
You MUST have micro filters with the bell capacitor in them, ( otherwise the phone will not ring ) for each Telephone.
I now have all my extensions connected with filtered phones using Solwise filters purchased back in 2003.
The effects are dramatic. All my phones are now crystal clear transmission.
Now I get unbelievable train up and download speeds.
I spoke to a plus net customer at work and he tried it tuesday night and his download speed went from 100K to 800K!
I brought a CE marked ADSL from the local Hardware store and it would only allow my ADSL modem to train up at 2800. The bell wire ( pins 3 or 4 ) were direct connected through.
After a reboot and a wait for my BRAS profile to re sync, My broad band may be broad band instead of hairline band!
My BRAS profile has been 4500 for three days now, instead of 500
Soddinghell
Newbie
Posts: 4
Registered: ‎26-08-2007

Re: Old chesnut-speed

Thanks for the info guys.
BT fitted a filtered face plate so I dont need filters on my extensions (or so he said)
When BT was here the margin was mostly 0db. He didnt seem to make much of it!
I assume this is the noise between the router and the exchange and not the pc. I am also assuming that a filtered faceplate and the router pluged into this as done by BT is the best possible solution.
As I write this the connection is as follows
ADSL Link  Downstream  Upstream
Connection Speed 3616 kbps 448 kbps
Line Attenuation 56 db 15.5 db
Noise Margin 2147483647 db 19 db
and has not altered in the last half hour I have been watching it.
Should I still do the "disconnect everything" checks.
As I was writing this I had a call from PN support staff who noticed the negative noise margin and said something about a split line.They are passing it back to BT.
We'll have to wait and see!