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Unsure what my ADSL is doing...

spader
Grafter
Posts: 41
Registered: 20-12-2014

Unsure what my ADSL is doing...

Hi,
Got back from my holidays to find my service nice and stable; IP profile 20.9Mb, modem reporting "max bandwidth" ~23000kbps, ping good and low, no packet loss (local LoS and error seconds while I was away, but I think they must have come in a bundle or something, as the count has barely moved in the four days since my return), no FEC errors (meaning no interleaving aka fastpath, as I understand it). The last checks I did on the 5th showed pings to Sheffield of 17ms, and downstream SNR dropped from 6 to 2.4 over the Christmas period.
However, speed test results were consistently topping out just over 18Mb (speedtest & plusnet) and not getting near 21Mb (before and after my holiday break).
Today though, I see my IP has changed (speedtest now thinks I'm in London), my ip Profile has dropped to 19.4, my ping has increased (~10ms), and I have FEC errors. But(!), my modem is reporting max bandwidth of 25000kbps, and the speed I'm getting is still the same (~18.25 consistently).
So I'm wondering a few things.
1) Why turn on interleaving? The error counts don't seem to have changed since I looked on Monday, and when I played some games Mon/Tuesday evening everything was fine.
2) Why am I not getting near the IP profile? (I understand why one can't hit "max bandwidth", but I seem to be capped at 18 for some reason.)
3) Why has the max bandwidth downstream increased anyway? More juice from the exchange for the 4dB SNR?
4) My upstream attenuation is stupidly low, and I've seen other people talking about having their upstream uncapped, but I'm stuck on 1Mb - what is the definitive word on this? 1.5Mb doesn't seem like much to ask!
Sorry to spam the queries, but I obviously want to have optimal performance and some of this stuff is confusing. Any info appreciated  Wink
23 REPLIES
spader
Grafter
Posts: 41
Registered: 20-12-2014

Re: Unsure what my ADSL is doing...

No ideas?
Superuser
Superuser
Posts: 12,605
Thanks: 3,878
Fixes: 25
Registered: 22-08-2007

Re: Unsure what my ADSL is doing...

Hi,
First to all intents and purposes, the Maximum Bandwidth is meaningless and does not "inform" the situation.  The relevant figure is the "Bandwidth".  On 21CN services, the IP Profile will e 88.2% of the synch (bandwidth) value.
Looking back at your pre-Christmas stats - here http://community.plus.net/forum/index.php/topic,135121.msg1183726.html#msg1183726 - would deliver a profile of 19.3Mbps.  I'm therefore a bit surprised that you report having had a 21Mbps PROFILE - that would imply a synch speed in excess of 23.8Mbps.  Have you seen a synch speed that high?
spader
Grafter
Posts: 41
Registered: 20-12-2014

Re: Unsure what my ADSL is doing...

I'll have to check what it is now, but I think it's over 22000kbps anyway - can't remember what it was last Monday or while I was away (but certain the IP profile was 20.9).
Looking back at my pre-Christmas stats I can maybe see why I was only getting 18.2Mb last week - I hadn't rebooted the router since the IP profile went up to 21. Plausible, or should I still have had 19Mb?
If you say max bandwidth is practically meaningless I'll believe you, but I'm still wondering why it would go up!
Any idea about the interleaving or my IP location?
Superuser
Superuser
Posts: 12,605
Thanks: 3,878
Fixes: 25
Registered: 22-08-2007

Re: Unsure what my ADSL is doing...

Quote
Max Rate
The sync rate you could attain if any line card or DSLAM restrictions were removed
Read more: http://www.kitz.co.uk/adsl/linestats_explanation.htm#ixzz3OcQDQ7Lq

As I say nearly meaningless as it requires limitations set to provide optimal performance of your line and others in your cable bundle.  For what you need to consider, current synch rate is the one that matters and is the one upon which the IP profile is calculated.
Interleaving in effect moves a degree of error correction out to the router thereby avoiding the need to retransmit error packets.  There is a slight trade off in latency for the benefit of improved stability and clean data transmission.
Looking at your stats here - http://community.plus.net/forum/index.php/topic,135121.msg1183726.html#msg1183726 - as a point of reference, for a 14dB line, you are darned close to the expected 22.4Mbps synch rate @6dB.
That DS synch rate 21.924Mbps will deliver a BT profile of 19.34Mbps and a PlusNet profile of 19.3Mbps.  The US rate is pretty hot too.
Frankly your line is doing well.
spader
Grafter
Posts: 41
Registered: 20-12-2014

Re: Unsure what my ADSL is doing...

Yes, I know  Wink
But, I think it was doing pretty well without interleaving too!
spader
Grafter
Posts: 41
Registered: 20-12-2014

Re: Unsure what my ADSL is doing...

Hi,
So it's been another wee while without any problems (LOS error count doesn't seem to have changed at all) and as I'm not sure was required anyway, can I have interleaving taken off, please? Unless there's some pressing not to. Bear in mind that gaming is my primary net-related activity!
Thanks Smiley

*edit
Just read something about throughput. Suggests with a sync of 22Mb and IP profile of 19.5 you should expect 19Mb or just over. I'm still (extremely consistently) at 18.2/18.3Mb. Is this normal?
Also I'm still confused about the upload speed. This thread:
http://community.plus.net/forum/index.php/topic,126012.0.html
and others seem to suggest mine could be uncapped. Unless it's already uncapped... I've certainly heard of more than 1Mb upstream though, and my line is surely good enough for it. Or no? Eerp  Undecided
Community Gaffer
Community Gaffer
Posts: 17,665
Thanks: 658
Fixes: 162
Registered: 05-04-2007

Re: Unsure what my ADSL is doing...

Quote
can I have interleaving taken off, please?

Your line looks stable enough to cope with this, so I'll go and place an order to remove interleaving. These complete the next working day.
Quote
suggest mine could be uncapped. Unless it's already uncapped.

Your upload is uncapped, it's synced at 1175. If it was capped it'd be around 448.
If this post resolved your issue please click the 'This fixed my problem' button
 Chris Parr
 Plusnet Staff
spader
Grafter
Posts: 41
Registered: 20-12-2014

Re: Unsure what my ADSL is doing...

Thanks, Chris.
I take it that's the maximum I can expect it to sync at then... Well, s'pose I don't need much upstream bandwidth for gaming anyway so it's all good!
Will report back whatever changes I see regarding latency or stats on the router. (Will I need to power it down at some point?)
Smiley
Community Gaffer
Community Gaffer
Posts: 17,665
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Registered: 05-04-2007

Re: Unsure what my ADSL is doing...

You shouldn't do, when the order completes it normally triggers a disconnection.
If this post resolved your issue please click the 'This fixed my problem' button
 Chris Parr
 Plusnet Staff
spader
Grafter
Posts: 41
Registered: 20-12-2014

Re: Unsure what my ADSL is doing...

Hi!
Interleaving off, ping down, sync rate up! (Will my IP profile rise to catch up with it?) I see the SN has decreased a little too... My primary concern is stability so I can live with 18Mb and a touch higher SN margin, I suppose. And it knows I'm in the Sheffield area again, yay! Pinging 10ms quicker to London and Sheffield, 15ms to Peterborough, and a steady 13/14ms to my favourite gaming server.
Uptime: 0 days, 14:55:48
DSL Type: G.992.5 annex A
Maximum Bandwidth (Up/Down) [kbps/kbps]: 1,136 / 23,288
Bandwidth (Up/Down) [kbps/kbps]: 1,131 / 23,928
Data Transferred (Sent/Received) [MB/MB]: 8.82 / 107.27
Output Power (Up/Down) [dBm]: 10.5 / 16.5
Line Attenuation (Up/Down) [dB]: 8.0 / 14.0
SN Margin (Up/Down) [dB]: 7.0 / 2.0
Vendor ID (Local/Remote): TMMB / IFTN
Loss of Framing (Local/Remote): 0 / 0
Loss of Signal (Local/Remote): 131,074 / 0
Loss of Power (Local/Remote): 0 / 0
Loss of Link (Remote): 0
Error Seconds (Local/Remote): 196,607 / 0
FEC Errors (Up/Down): 29,883 / 0
CRC Errors (Up/Down): 1,280 / 56,707
HEC Errors (Up/Down): 0 / 46,580

How come there are still upstream FEC errors though? I had none before (pre Tuesday 6th). The error seconds and LoS presumably all came in a bunch when interleaving was being modified, because they are no longer rising.
Thanks  Cheesy
Community Gaffer
Community Gaffer
Posts: 17,665
Thanks: 658
Fixes: 162
Registered: 05-04-2007

Re: Unsure what my ADSL is doing...

Interleaving can be on for the upstream but off for the downstream, I wouldn't worry too much about that though.
Quote
sync rate up! (Will my IP profile rise to catch up with it?

It should do straight away, I've bumped our profile to 20500 so if you try a single disconnect/reconnect from within the router and see if that helps.
The rest of the stats are looking really good!
If this post resolved your issue please click the 'This fixed my problem' button
 Chris Parr
 Plusnet Staff
spader
Grafter
Posts: 41
Registered: 20-12-2014

Re: Unsure what my ADSL is doing...

Thanks!

Nice!
Bt thinks this:
Download speedachieved during the test was - 19.24 Mbps
For your connection, the acceptable range of speeds is 4 Mbps-21 Mbps.
IP Profile for your line is - 21.11 Mbps

After so long living miles from telephone exchanges I never thought I could be this pleased with good old ADSL!
Do I need the upstream interleaving though? If anything, the speedtests I've just done seemed a little less fluid on the uploads. My pings are now a couple of ms even lower Wink
Plusnet Help Team
Plusnet Help Team
Posts: 5,642
Thanks: 533
Fixes: 205
Registered: 01-01-2012

Re: Unsure what my ADSL is doing...

That's a bit bizarre.
Our system is showing interleaving as being completely off and when I view error data for your line I can't see any FEC errors recorded on the upstream at all.
Has the count increased since your last post?
If this post resolved your issue please click the 'This fixed my problem' button
 Matthew Wheeler
 Plusnet Help Team
spader
Grafter
Posts: 41
Registered: 20-12-2014

Re: Unsure what my ADSL is doing...

Hmm, will check when I get home.
When the IP profile was modified I didn't actually restart the router. Shall I disconnect and then power it down? That will clear all the counts, correct?
Not that I feel it matters much, but what determines the IP address you get? Some sites seem to recognise me as being in the London area!