More Line Stats

[zappaDPJ]

I've decided to have one last attempt at resolving my connection problems before a MAC request. I've pulled together a few stats for my own information and to see if there's any indication of what the problem might be.

Two modem stats (different modems) from when I first connected to the 8Mb/s service:

Bandwidth (Up/Down) [kbps/kbps]: 448 / 7.072
Output Power (Up/Down) [dBm]: 11,0 / 19,0
Line Attenuation (Up/Down) [dB]: 13,0 / 26,0
SN Margin (Up/Down) [dB]: 25,0 / 6,0

ADSL Link Downstream Upstream
Connection Speed 7808 kbps 448 kbps
Line Attenuation 26.0 db 12.5 db
Noise Margin 6.4 db 22.0 db

Modem Stats and a speed test on first connecting to 24Mb/s:

ADSL Link Downstream Upstream
Connection Speed 13191 kbps 1191 kbps
Line Attenuation 28.5 db 13.0 db
Noise Margin 6.2 db 5.9 db



Two speed tests including a BT test a week later:

Test1 comprises of Best Effort Test:  -provides background information.
   Your DSL connection rate: 285 kbps(DOWN-STREAM),  1221 kbps(UP-STREAM)
   IP profile for your line is - 135 kbps
   Actual IP throughput achieved during the test was - 102 kbps



Modem stats and a BT speedtest two weeks later after BT intervention:

ADSL Link Downstream Upstream
Connection Speed 9210 kbps 1223 kbps
Line Attenuation 35.5 db 17.5 db
Noise Margin 6.10 db 6.5 db

Test1 comprises of Best Effort Test:  -provides background information.
   Your DSL connection rate: 9210 kbps(DOWN-STREAM),  1223 kbps(UP-STREAM)
   IP profile for your line is - 4000 kbps
   Actual IP throughput achieved during the test was - 3468 kbps

The current situation:

ADSL Link Downstream Upstream
Connection Speed 7060 kbps 1200 kbps
Line Attenuation 35.5 db 17.5 db
Noise Margin 11.75 db 7.0 db

Test1 comprises of Best Effort Test:  -provides background information.
   Your DSL connection rate: 6950 kbps(DOWN-STREAM),  1169 kbps(UP-STREAM)
   IP profile for your line is - 6000 kbps
   Actual IP throughput achieved during the test was - 2112 kbps

At the moment it appears from IDNet records that I had a nearly a week within the last fortnight of stability with no reconnects. However in the last few days there have been quite a few, one being a total loss of service for about an hour. The continual disconnects don't in my view really explain the throttling on the downstream and this does seem to be a recent phenomena.

I've noticed that at some point my attenuation on the downstream has jumped by 10 db. Does anyone know what would cause this?

I've decided not to revert back to 8 Mb/s because I can't find anyone that has had any real success with that option so my choices are to try and see if there's any that can be done with my current connection or take a gamble and switch ISPs.

[Rik]

In your position, Zap, I'd be sorely tempted to try AAISP or Zen. Whatever you decide, don't be a stranger, custom is not a pre-requirement of membership.

[Steve]

But will he end up on ADSL2+ with Zen automatically or are we not worried about that? Is the relatively low through put due to errors or congestion?

Edit AAISP will put you adsl2+ if its available and Zen are still in trial period.

[Rik]

He will, Steve, and we don't know.

[Steve]

Presumably Zappa has been informed by idnet why throughput is low?

[Rik]

I'm not sure, Steve, there seem to have been mixed messages.

[zappaDPJ]

To answer a few questions; I would migrate to AAISP, I've spoken to them at length and based on the stats I've given them they have offered a couple of suggestions that sound hopeful including a line bonding option if my currently line really is as bad as it appears which is something that is still in question. My next door neighbour has a line profile of 14 Mb/s so I don't see why I can't get something similar. AAISP are also now rolling out FTTC trials which is ultimately what I'm aiming for regardless of what happens in the short term.

The low throughput is a recent phenomena and it's gone hand in hand with my latency going up by 150%. It could be congestion I guess, I do know a lot of people in my street have switched to ADLS2+ in the last couple of weeks but my gut feeling says it's a problem elsewhere. I've checked a couple of their connections and they are pinging what I was getting when I first connected. There was a suggestion earlier in the week that someone was leaching off my connection but I've taken steps to prevent that if it was happening at all.

To be honest the whole thing is a mystery to me, I'm by no means an expert on communications infrastructure but I have worked in the IT industry for nearly 25 years and I'm at a loss to understand any of this, particularly the change in line attenuation.

Whatever I do I won't be a stranger, it's rare these days to find a forum where the members speak a language I can understand, 0N3 D4y w3 m19h7 4lL H4v3 70 k0mMuN1C473 l1k3 7h12  

[zappaDPJ]

I didn't realise that speedtest.net stored all the tests done from your location regardless of ISP. I've just taken a look through my line history and it certainly puts thing in perspective. I conducted a number of tests when I was with Be at peak times to prove the congestion on their network was pretty dire. Here are the accumulated results for the 3 months I was with them:

Average Download Speed along with a best test result:

Average Download Speed
9.06 Mb/s
Average Upload Speed
0.88 Mb/s



Here is the same data for IDNet since upgrading to ADLS2+:

Average Download Speed
2.11 Mb/s
Average Upload Speed
0.90 Mb/s



I've been told that ISPs on LLU equipment have more control and therefore can adjust s/n to give better throughput but would it really allow things to be that much better? This clearly shows that my line can sustain a high throughput and shows it has done so in the past so what could have changed to bring it down to speeds more representative of a fire and damp blanket?

[Sebby]

The thing with someone like Be is they don't have a DLM that automatically adjusts your target SNRM. In fact, you can adjust it yourself (3, 6 or 9dB) in the control panel.

[Rik]

None of which will help if the problem is in 'the last mile, of course.

[zappaDPJ]

I've been trawling the net today to see if I can find an explanation that would explain why my line attenuation has increased by 10 db. The only explanations I can find are a) faulty internal wiring, b) a faulty modem/modem reporting incorrectly or c) a line fault.

As I have no internal wiring at all and I currently have 4 modems to try I can only assume that there is a line fault which seems to have coincided with the visit from the BT engineer. Does anyone know of any other reasons why this may occur?

[Rik]

Relative to what, Zap. My attenuation went up by 6db on moving to WBC due to the higher frequencies used.

[Gary]

When i went at my old home on to O2's LLU my attenuation went up from 46 top 52db its a characteristic of adsl2+ it appears. Although at my new home I am not likely to see that for years yet, with no sign of WBC, which now seems a bit of a god send 

[zappaDPJ]

My line has always had a 26 db attenuation. It did go up slightly when I was connected to WBC (28db) but around the time I had the BT engineer call, it jumped to 36 db.

I'm probably clutching at straws, trying to diagnose my line problem myself, but there has to be a reason why my connection is so abysmal compaired to other BB users in my street.

[Rik]

It certainly sounds like it's engineer induced, then Zap, but knowing what and where is going to be harder to work out. Do IDNet know what was put on the engineer's report?

[zappaDPJ]

They do and unfortunately it's totally at odds with what the engineer told me. He tested my line at intervals back from the exchange and found no fault in the line. However he did say that the line had a joint that he could bypass by putting me on another pair which would bring me slightly closer to the exchange. Once he had done that he tested the line back again said for the distance, 1 km, I should get a very good service but there was a problem at the exchange and he would report that I needed a lift and shift which was the next step in the fault finding procedure.

Unfortunately all that was reported to IDNet was that my line had been demonstrated as working or words to that effect. IDNet were going to pursue it with Openreach but I guess that came to nothing.

[Rik]

It depends what the engineer put on paper, sadly.

[Simon]

Why would the engineer say something different to the customer, to what he puts in his report to the ISP? 

[Rik]

It's easier to get out the door.

[zappaDPJ]

I wish I knew what the real situation is. The engineer went to some lengths to assure me that he would submit a detailed report. It's this that has left me in a state of limbo and baring an administrative error, it implies that someone is being economical with the truth. There's a fault somewhere, there has to be, it just seems it's one of those faults that can't be fixed which is more than annoying considering I moved to this property specifically because it had a sound BB connection.

[Rik]

Some engineers are good, some are bad. I've come across those that tell the customer what they want to hear, then post a fault cleared report when they go back. The problem is that BT answer only to themselves.

[zappaDPJ]

This is not something to dwell on but I had a few connection problems during the night although I can't see any evidence of it in my router log. Today my daughter was the first to notice that we are not getting any video buffering and sure enough a cheap and cheerful speedtest shows why.



Would the outage on the central have anything to do with this (the positive effect)?

[Rik]

It shouldn't, as you are on the Hostlink, not a central (you haven't switched back to Max and I've forgotten, have you?)

[zappaDPJ]

Still on ADSL2+ Rik and totally undecided what to do, especially now. I'm only 1 Mb/s away from what I was getting on Max which is all I really need. I've noticed my latency has increased, it was 10ms so perhaps someone has been playing around with interleaving?

[Rik]

It sounds like it, Zap, mine was certainly kicked in quite early. That said, then, last night didn't affect you or me.