Help ADSL2+ issues

Firstly apologies to anyone who may have seen my long running issues on other forums. However I feel that as I seem to have a number of multiple issues, the more I air them, the more likely someone might be able to come up with an answer that might eliminate one or more of them.

I upgraded to ADSL2+ at the end of last year. My line stats are

noise margin downstream: 9 db
output power upstream: 11 db
attenuation downstream: 19 db
noise margin upstream: 5 db
output power downstream: 19 db
attenuation upstream: 12 db

IP Profile 13000
Synch rate 15439 kbps

Essentialy therefore I should be getting throughput speeds of 10 meg. However that has not been happening and I am not acheiving any greater throughput than when I was on ADSL2 - around 7 meg when connected to the modem by cable. Time of day makes no difference so network traffic can be discounted.

I was experiencing some line drops and after persistance with BT (using their community forums) I have had a home engineer visit and a faulty circuit has been identified at the exchange and I am now on a different circuit. The Engineer also replaced my master socket.

Since the engineer visit I have noticed my noise margin and error count increase. The noise margin was fluctuating between 7dB and 9dB - now it fluctuates between 9dB and 10 dB accrding to Routerstats.

This was the position on 9 January

near-end FEC error fast: 263
near-end FEC error interleaved: 0
near-end CRC error fast: 169
near-end CRC error interleaved: 0
near-end HEC error fast: 857
near-end HEC error interleaved: 0
far-end FEC error fast: 0
far-end FEC error interleaved: 0
far-end CRC error fast: 1701
far-end CRC error interleaved: 0
far-end HEC error fast: 0
far-end HEC error interleaved: 0
ADSL uptime 18:18:56

This is the position now

near-end FEC error fast: 0
near-end FEC error interleaved: 44125
near-end CRC error fast: 0
near-end CRC error interleaved: 376
near-end HEC error fast: 0
near-end HEC error interleaved: 1694
far-end FEC error fast: 0
far-end FEC error interleaved: 304
far-end CRC error fast: 0
far-end CRC error interleaved: 664
far-end HEC error fast: 0
far-end HEC error interleaved: 0
ADSL uptime 12:21:38

The exchange is set to auto and interleaving was turned on before the engineer visit.

I have a Zyxel P660HW T1 V2 and have confirmed the firmware is correct with Zyxel support.

My modem has had to put up with a lot of powering off since the upgrade through movement to the master socket from an extension, reboots and complete removal during the engineer visit. It has also had to cope with two power cuts!

Throughout the period I have noticed that wireless speedtests have been consistantly lower than wired ones returning speeds of around 3.5 meg. This applies equally to my PC with Avira anti virus two rooms away from the modem and my laptop with Norton Anti Virus in the same room as the modem (within touching distance).

I seem to have one issue with the line and another one with wireless speeds. Whilst the line issue is something that I can try to persuade BT to check (high number of errors and noise pointing to something being not quite as it should), they won't obviously address the wireless speed issue. I have run inssider and I am happy that I am not getting any interference and I have down the REIN test by radio - the router was emmiting noises like an old VW Beetle whilst my dongle was making a high pitched shrill. No other electrical devices were emmitting noises.

I have been thinking about upgrading my modem to an N standard and am considering either the Billion 7300N or Billion 7800N or possibly the Linksys WAG 320N as the duel band capability might address any external noisei nterference that I cannot identify. However I am loathed to invest in something that will not make any difference immediately either by increasing the wireless speeds or improving the line stability.

I have a few months to sort this out. Currently I have just the PC and laptop but before the analogue TV signal is switched off I want to upgrade the TV. I would like to get one with Wi-Fi capability giving the options of media streaming but untill I can get my actual throughput speeds to a higher level and address my wireless speeds, I feel that the investment in a Wi-Fi TV cannot be justified.

The specific questions are:-

Could my modem be the cause of these errors because of what it has had to put up with?

Could the New master socket be the cause of the sudden increase in errors and noise margin?

Could either of my antivirus and Firewall solutions be affecting my wireless speeds?

Given what I want to acheive eventually assuming the line issues can be sorted, which would be the best modem to go for? I want to be future proof. I brought the Zyxel when I was still on ADSL1.

I know that there are a lot of issues, but all suggestions in addressing any one of them or all of them would be welcome.

the error levels aren't high. If you do an extended ping test to a reputable site what packet loss do you see ?

What operating system do you have, have you checked the MTU and RWIN values on a tweak testing site.

Booting windows into safe mode and running a speedtest would reduce the impact of security products, or remove them completely for testing and then replace.

In reply to a post by yarwell:

the error levels aren't high. If you do an extended ping test to a reputable site what packet loss do you see ?

But they have gone up. Why have they gone up? Pointers on how to do an extended ping test please.

In reply to a post by yarwell:

What operating system do you have, have you checked the MTU and RWIN values on a tweak testing site.

PC is Windows XP, Laptop Windows 7. You have lost me on the rest.

In reply to a post by yarwell:

Booting windows into safe mode and running a speedtest would reduce the impact of security products, or remove them completely for testing and then replace.

Would a wireless test to BT Speedtester work in safemode? I know that the other Speedtesting sites can produce very strange results with my set up. I had a result of over 30 meg on one which is obviously not right. BT Speedtester is the only one that BT seem to take notice of.

Hello,

Something doesnt seem right, are you able to plug your router directly in the test socket under the faceplate on the master socket and leave it like that for a day or so whilst monitoring the downstream snr fluctuation.

If the 2db fluctuation has reduced, then it means there could be something bad in your internal telephone wiring in your house after the bt master socket.

Yes your antivirus software can cause slow speeds, if it running updates or running systems scans.

Something you need to be aware of, is with the big isp's like BT Broadband, they tend to over subscribe, and the speeds suffer like a traffic jam on the M25. If you do a speedtest at 2am in the morning and its really fast, then your answer is congestion/traffic jam.

As for your dream of making everything wifi by switching to wireless N, your going to be dissapointed. The specificatons what the manufactures put on the their products, are based on having a clear line of view, like standing in afield. This is an example.

If you have a little aeroplane which carries 6 people and flys at 400mph, but cant fly through a brick wall, buying concord which carries more passengers and has super sonic speeds, still cant fly through a brick wall.

ping www.bbc.co.uk -t then Ctrl/c to stop it after 5 minutes and get the numbers.

wireless probably works in safe mode, try it and see

http://www.dslreports.com/tweaks/ - run the test and post the tiny url from the bottom of the page.

You've gone from fastpath to interleaved, has the sync speed stayed the same ? You see more FEC errors with interleaving 'cos it has more data to correct them.

Edited by yarwell (Sun 27-Feb-11 16:12:20)

tweak test herewith I hope I have done it right.

I should add that I have finally managed to get my Home Hub 2.00 going but obviously still have a G rated dongle.

I am going to see whether the Home hub stabilises things a bit. I will do other tests if required.

Receive Window (RWIN): 17160

this is too small for a fast connection, it will limit the maximum speed you can get.
http://www.dslreports.com/faq/578 shows how to increase it, suggestions were on the tweak test report page - try 64,000 and 128,000 and compare speed test results at each.

This only applies to XP, later versions of windows are supposed to manage this better.

Interleaving usually reduces the maximum line sync usually, doesn't it? Like on 20CN Fast path peaks at 8128kbps, while interleaved is 7616kbps.

7616 is only the limit if the hardware doesn't do S=1/2 mode otherwise you get full speed. If it was 7616 to start with, interleaving wouldn't reduce it.

I have now resolved this issue. I replaced my Zyxel with a BT Hub that I thought was dead but with assistance from India call centre I have got it going.

Now acheiving 12 meg Speeds.

I can only conclude that my Zyxel circuitry was damaged due to a couple of Power cuts and line drops caused by faulty exchange circuitry.

VPI/VCI 0/38
Type PPPoA
Modulation ITU-T G.992.5
Latency type Interleaved
Noise margin (Down/Up) 6.9 dB / 5.7 dB
Line attenuation (Down/Up) 22.5 dB / 11.5 dB
Output power (Down/Up) 21.0 dBm / 12.4 dBm
Loss of Framing (Local) 0
Loss of Signal (Local) 0
Loss of Power (Local) 0
FEC Errors (Down/Up) 0 / 972
CRC Errors (Down/Up) 466 / 2147480000
HEC Errors (Down/Up) nil / 31957
Error Seconds (Local) 300

The errors are higher than what they were when I first upgraded to ADSL2+ - do they increase with higher speeds?

Would these speeds be OK for a Wi-Fi capable TV? I am not planning to go down the route of BT Vision but I would like BBC iplayer (and other services) capability on my next TV. I don't think that Infinity is going to reach these parts anytime soon so unless I can tweak things with a better modem/router this is probably as good as it gets.

In reply to a post by yarwell:

ping www.bbc.co.uk -t then Ctrl/c to stop it after 5 minutes and get the numbers.

wireless probably works in safe mode, try it and see

http://www.dslreports.com/tweaks/ - run the test and post the tiny url from the bottom of the page.

You've gone from fastpath to interleaved, has the sync speed stayed the same ? You see more FEC errors with interleaving 'cos it has more data to correct them.

The highest the connection rate acheived on fast was 13936 kpbs now on 14974 kpbs interleaved, but errors notably higher. It did reach 15942 kpbs but I had to reset the router thanks to BT FON playing havoc with my wireless connection. Whilst my rate might increase again, I am not expecting any major changes to throughput speeds.

I am not expecting any major changes to throughput speeds.

you won't on XP unless you increase the RWIN value.

before it was:

IP Profile 13000
Synch rate 15439 kbps

what now ?

Useless posting router stats w/out Connection Speeds

In reply to a post by yarwell:

before it was:

IP Profile 13000
Synch rate 15439 kbps

what now ?

As stated above and unchanged

Line state Connected
Connection time 2 days, 2:17:20
Downstream 14,974 Kbps
Upstream 1,064 Kbps


ADSL settings
VPI/VCI 0/38
Type PPPoA
Modulation ITU-T G.992.5
Latency type Interleaved
Noise margin (Down/Up) 6.2 dB / 5.6 dB
Line attenuation (Down/Up) 22.5 dB / 11.5 dB
Output power (Down/Up) 21.0 dBm / 12.4 dBm
Loss of Framing (Local) 0
Loss of Signal (Local) 0
Loss of Power (Local) 0
FEC Errors (Down/Up) 0 / 1646
CRC Errors (Down/Up) 890 / 2147480000
HEC Errors (Down/Up) nil / 32423
Error Seconds (Local) 548

In reply to a post by yarwell:

I am not expecting any major changes to throughput speeds.

you won't on XP unless you increase the RWIN value.

I have run the DSL Tweak tester again and it seems that Windows Dynamic management is working
http://www.dslreports.com/tweakr/block:491357?servic...
I note that BT run on PPPoA Enscapulation so just in case I have done a second test

http://www.dslreports.com/tweakr/block:491357?servic...
So basically my MTU should be 1470 and RWIN 256960?

As not stated above and the following appended:

In reply to a post by Tuliptownman:

Line state Connected
Connection time 2 days, 2:17:20
Downstream 14,974 Kbps
Upstream 1,064 Kbps

1500 MTU - easiest to stick at the default.

Was that the same PC as last time on the same network connection ? XP doesn't resize RWIN AFAIK and it's adapter specific.

To be honest, if I saw those stats from your router, I would say replace it. Upstream errors are almost always faulty wiring or equipment, and if those stats are accurate, you are sending a lot of upstream errors, which isn't going to help anything. It may also explain the poor wireless performance, but it is a bit of a tenuous link, but may be indicative of a router on its way out.

If you have a spare router, try that, easiest way to find out

To be certain, phone your ISP, and ask them to run a diagnostic. If they are vaguely competent, they'll be able to see the errors themselves, and can advise you accordingly.

In reply to a post by XRaySpeX:

As not stated above and the following appended:

In reply to a post by Tuliptownman:

Line state Connected
Connection time 2 days, 2:17:20
Downstream 14,974 Kbps
Upstream 1,064 Kbps

It is

The highest the connection rate acheived on fast was 13936 kpbs now on 14974 kpbs interleaved, but errors notably higher. It did reach 15942 kpbs but I had to reset the router thanks to BT FON playing havoc with my wireless connection. Whilst my rate might increase again, I am not expecting any major changes to throughput speeds.

Ok I'll grant that the upstream speeds aren't but no one has upstream speeds to write home about due to the physical limits. Sometimes I wish they could be quicker when sending emails with large attachments.

In reply to a post by yarwell:

1500 MTU - easiest to stick at the default.

Was that the same PC as last time on the same network connection ? XP doesn't resize RWIN AFAIK and it's adapter specific.

Thanks.

Same PC and connection. The only thing that changed was that I replaced a Zyxel G202 56kbps adaptor with a TP Link WN821N 300kpbs adaptor - I know T P Link are nothing to write home about but as the Home Hub 2 is N rated I needed something to test it out and there is not much choice in a provincial market town. T P Link is returning 130 kpbs but I have no idea whether that is due to router range or adaptor range or (perish the thought) manufacturer optimism.

If I decide to replace BT's freebie, I will get an adaptor from the same manufacturer - personally I am thinking either Billion or Linksys due to generally good reviews. I just wish Billion did a dual band one.

In reply to a post by b_bliss:

To be honest, if I saw those stats from your router, I would say replace it. Upstream errors are almost always faulty wiring or equipment, and if those stats are accurate, you are sending a lot of upstream errors, which isn't going to help anything. It may also explain the poor wireless performance, but it is a bit of a tenuous link, but may be indicative of a router on its way out.

If you have a spare router, try that, easiest way to find out

To be certain, phone your ISP, and ask them to run a diagnostic. If they are vaguely competent, they'll be able to see the errors themselves, and can advise you accordingly.

Thank you for your comments.

It's a BT Home Hub 2 and is newly supplied. The CRC upstream errors are a bug - now they have a Home Hub 3 its unlikely that they will fix it especially given the period that the Home Hub 2 has been available.

As I indicated earlier in this thread i was on a fast connection with my Zyxel but I was getting line drops and a lot more noise and slow throughput (both wired & wireless). Eventually a BT Openreach Engineer came out and diagnosed a faulty circuit at the exchange. He also replaced the master socket. The line went to interleaved prior to the switch (so I can't say its the circuit that they swapped it to). We did get a power cut before hand and I think it was this and the line drops that fried my Zyxel. As soon as I plugged the Home hub in the noise dropped instantly and the throughput increased immediately to what I am now getting.

I therefore have no idea what is the cause of the errors. I suppose I am going to have to put up with them - I am still getting higher throughput speeds than BT's average on ADSL2+. BT have indicated that they don't think the errors are an issue and given the speeds I am getting I don't think I will get them to do anything further. Of course the hub hides the real upstream CRC errors. Given that you can't get much more than 1 meg upstream its not worth the hassle.

I have been thinking about buying a decent modem router as the diagnostic capability on the Home Hub 2 is limited (and it hides the real upstream errors). I am thinking of either a Billion 7300N or 7800N or a Linksys WAG 320N. The dual band capability of the latter has its attractions, but the very high approval ratings of both Billion's and their error handling also is attractive. I think that Zyxel have lost their way on the domestic market and their support was not the best when I was trying to eliminate potential causes of low speeds and high noise during the last couple of months.

looks like the new adaptor inherited a better RWIN value, such are the vagaries of Windows!

I did not notice your subsequent post with the speed, but, for the removal of doubt, it is best to post all the relevant stats together contemporaneous so that they correspond to each other.