Broadband Related > ADSL Issues
Slow connection
Russcos:
Hi folks, I am a first user to Kitz and find it very informative.
I have an issue which i hope i can find some answers from this site, after reading some posts about ADSL i was amazed about how much i didnt know about connection speeds.Here's my dilemna... I have BT 8mb broadband and after upgrading from i think 2mb last year,i didnt have any problems until as of late. When my line was going live last year with the 8mb service i was advised to leave the router on for 10 days until the line stabilised and i noticed a speed of 8128 d/l and 448 u/l speeds straight away, what i didnt know until i found this great site was the speeds were just a sync withe the local exchange,as i just thought i was getting 8mb downstream and 448 upstream,happy days i thought until now. Since last year i have been switching off my pc and router as i thought since my line was at 8128 i wouldnt have any problems. A few weeks ago i noticed noise on my phone when the router was switched on and no noise when switched off, I have a ADSL faceplate splitter and i even removed it and plugged in a filter to the test socket but the noise was still there. My speeds slowed down aswell and i was getting at best 4700 d/s and 448 u/s. After numerous calls to BT they finally came out and traced the fault to the exchange, and the engineer said he rewired 6 points of my line in there. After a reconnect, with a quiet line,i checked the stats of the router and i was getting 6700ish d/s and 448 u/s, i switched the router on and off and it kept connecting at different speeds. I now know not to keep switching the router off and on but i now have a d/s speed of 7022 and upstream of 448, i have done speed tests as per the instructions from this site and i was shocked to see a speed of 2879kbps d/s and 398 u/s as i thought i would have speeds of 7022 kbps. I am sorry to go on but how do i get my line back up to the 8128 d/s or sync, and a decent download speed. Many thanks for a great site in which i have had my eyes opened about ADSL.
soms:
--- Quote ---fter numerous calls to BT they finally came out and traced the fault to the exchange, and the engineer said he rewired 6 points of my line in there.
--- End quote ---
As you can appreciate, a line is a pair of wires and this would suggest that your line might have been put onto a different pair between your home and the exchange - six points being at the various DPs, joints and cabs inbetween.
The sync speed suggests that any "new" pairs in use are loosing more of the ADSL signal through noise than your original line did when you first had ADSL. This could be because your line might now have a different, and longer route through the network cables to the exchange. It might also suggest resistance on the line which does not affect speech but is reducing ADSL performance or otherwise perhaps radio interference which is affecting ADSL performance.
No doubt the others here will add some comments of their own ;)
soms.
Russcos:
Hi Soms,
thanks for your reply, maybe i've worded it wrong but i'm sure the engineer said the wires were cut and rejoined or rewired so i just assumed it was to the original points where he cut them or words to that effect. To be honest i was just glad to have my phone service resumed and my 8mb broadband back or so i thought.
kitz:
Hi and welcome. :)
>> but i now have a d/s speed of 7022 and upstream of 448,
I also suspect that the problems on the "old wires" may have caused the DLM to make a few changes to the way your adsl connection may now behave.
1) Interleaving may have been turned on which means that the theoretical maximum speed that you line will sync at is 7616.
2) Increased your target SNR. This will stablise problem lines but means that you wont be able to sync at the speeds that you previously were able. The default is 6dB, but it can be increased to 9, 12 or even 15dB. Each increase will lower the attainable sync speed.
Which router do you have? If you provide us with your line stats then we may be able to have a look and see if we can see anything obvious.
The best way of finding out what your Target SNR is set at, is by looking at your SNR Margin immediately after a reboot.
>> I now know not to keep switching the router off and on
Indeed because this can fool the DLM into thinking that your line is still problematic and it will respond to this by lowering something called your IP profile. Your IP profile wont limit your sync speeds... but it will limit your throughput speeds which may be why you are only seeing speeds of around 3Mb now.
If you do a BTw performance test it should tell you what your IP profile is set at.
If you can get back to us with all of the above info - then we may be able to advise you further on how to get your speeds back up a bit nearer to what they were.
Russcos:
Hi Kitz, thanks for your reply,
I have done a speed test and heres the results
Test1 comprises of Best Effort Test: -provides background information.
IP profile for your line is - 5500 kbps
DSL connection rate: 448 kbps(UP-STREAM) 7008 kbps(DOWN-STREAM)
Actual IP throughput achieved during the test was - 5069 kbps
I also am using a Voyager 2091 router
line stats
Line mode.. G.DMT
Latency Type.. Interleave
Line coding ..trellis on
STATISTICS Downstream Upstream
Line Rate 7008kbps 448kbps
Noise margin 14.9 db 24 db
Line attenuation 21.0 db 9.0 db
Output power 198. dbm 12.4 dbm
K 220 15
R 16 16
S 1 8
D 32 4
Super Frames 19055 19053
Super Frame Errors 0 0
RS Words 1783638 212942
RS correctible errors 0 0
RS uncorrectable errors 0 0
HEC Errors 0 0
OCD errors 0 0
LCD errors 0 0
ES errors 0 0
Hope these figures help in trying to resolve my issues Kitz.... Thank you.
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