Underwhelming ADSL2+ Service

[didahdit]

IDNet recently upgraded me to ADSL2+.  I was told I could expect speeds up to 15 meg from the 20 meg service.  This seemed reasonable as I was getting 6 meg from the existing 8 meg service. Since the upgrade a month ago my speed has dropped from 6 meg initially to 3 meg now.  See speed test below.  (speed test taken from test jack - ie face plate removed from BT box) It seems ADSL2|+ should carry a health warning.  Beware:  You speed may go down instead of up.  The test claims I am configured for 3000 kbs.  This appears to change because it has been variously 8000, 6000 and 4000 in the month since I upgraded!   Who, what, or how does this configuration get set?   Is ADSL2+ suffering from its own success or is it just smoke and mirrors marketing hype?

quote
Test1 comprises of two tests

1. Best Effort Test: -provides background information.

   Download Speed
   2873 Kbps
   
0 Kbps   4000 Kbps
Max Achievable Speed

Download speedachieved during the test was - 2873 Kbps
For your connection, the acceptable range of speedsis 1200-4000 Kbps.
Additional Information:
Your DSL Connection Rate :3544 Kbps(DOWN-STREAM), 828 Kbps(UP-STREAM)
IP Profile for your line is - 3000 Kbps
The throughput of Best Efforts (BE) classes achieved during the test is - 15.21:19.64:65.15 (SBE:NBE:PBE)
These figures represent the ratio while sententiously passing Sub BE, Normal BE and Priority BE marked traffic.

The results of this test will vary depending on the way your ISP has decided to use these traffic classes.

2. Upstream Test: -provides background information.

   Upload Speed
   659 Kbps
   
0 Kbps   828 Kbps
Max Achievable Speed

>Upload speed achieved during the test was - 659 Kbps
Additional Information:
Upstream Rate IP profile on your line is - 828 Kbps
unquote

Any help or info gratefully received.

Bob

[Rik]

You may have a router which is not ideally matched to your line, trying a different make/model would be a worthwhile check. If it's not that, we have seen several cases where lines, for some reason, just don't support ADSL2+ as well as they did ADSL. If this is the case, IDNet can have your line set to modulate as ADSL, you keep the higher download allowances but obviously lose some upload speed unless you were on a Pro package.

[Lance]

Your profile is determined from your sync speed.

Could you post your router stats please?

Also, who told you to expect 15mb? That's an unrealistic figure given that you weere previously only at 6mb.

[esh]

You may have a router which is not ideally matched to your line, trying a different make/model would be a worthwhile check.

Does anyone else realise how ridiculous it is that this is actually sane advice?

It's like going back to the bad old days of mysterious init commands for your dial up modem. You try and understand things and it all looks like some mysterious black art in the end. If there were options to tweak and examine the end results, fine. But it's entirely unreasonable that general home end-users should have a stack of DSL modems on hand to swap and match - these things do cost money after all. You'd think ADSL2 specifications are just that, specifications. If a device follows them, then it should work, and not particularly much different from any other. Okay, I'm rambling. I have a headache this morning. That's my excuse.

I do know that ADSL2 is super picky when it comes to noise, and BT's profile system is on a hair trigger. When on ADSL2 in rented accommodation in the Coventry area, the DSL2 line varied between 1 and 3 Mbit every day. That wasn't IDNet of course, but I think you should expect the speed to vary somewhat unless you have a very good line. Perhaps others have more direct experience than me.

I assume this is probably a downside of pushing DSL technology to its max, or is BT really configured that badly? (Yes, that is a serious question )

[Rik]

If only we knew, esh.

[pctech]

ADSL/2 is a technology that was designed to allow telecom companies to offer affordable high speed connectivity using existing assets such as the local copper loop.

The trouble is that as its RF based the further you are away the poorer speed you will get and some transceivers that handle some line lengths and types better than others.

I really don't think ADSL should hsve got off the International Telecoms Union (ITU's) drawing board and there should have been effort put in to develop something better.

[didahdit]

Stats from my Netgear 834N router.

System Up Time 213:58:49
Port    Status    TxPkts    RxPkts    Collisions    Tx B/s    Rx B/s    Up Time
WAN    PPPoA    104009    137362    0    3067    13312    02:33:40
LAN    10M/100M    5068052    4766050    0    3939    1424    213:58:40
WLAN    11M/54M/270M    0    0    0    0    0    03:57:09

ADSL Link    Downstream    Upstream
Connection Speed    3547 kbps    828 kbps
Line Attenuation    27.0 db    12.3 db
Noise Margin    29.9 db    8.6 db

I can't recall where I read the 15 meg speed but it stuck in my head.  .  However IDNet did say in their Broadband Order completed e-mail that my connection speed to the exchange is now 12mb with 11mb profile.  Speed may vary.  It's never been that high - 8 meg is the highest I've noticed.  (I don't check every day)  Recently it's dropped significantly though.

I only have one ADSL2+ router so can't change it.  My other one is just an old ADSL type.

Regards
Bob

[Rik]

That noise margin is at the heart of your problem. Can you plug the router into the test socket if you have one?

[MisterW]

If only we knew, esh

If only BT knew

[Rik]

 

[didahdit]

That noise margin is at the heart of your problem. Can you plug the router into the test socket if you have one?

It is currently plugged into the test socket - (the one behind the faceplate) via the filter.  I assume you don't mean I should remove the filter?

Bob

Bob

[esh]

Maybe it's time for a new filter?

[Rik]

What else is connected to the line, Bob?

[didahdit]

What else is connected to the line, Bob?

A BT Response 120 Telephone via the filter

Bob.

[Rik]

What happens if you disconnect that and power it down?

[pctech]

Thats quite an old phone now as we used to have one about 13 years ago, maybe the adapter is starting to create some noise?

[john]

I don't know whether this is true or not but someone was telling me recently that they were experiencing performance problems with their broadband and when they contacted their ISP regarding this (don't know which ISP) they advised him to change his filters as they claimed they degrade over time. Although sceptical that there was a problem with the filters he did change them and his connection did significantly improve.

[pctech]

That is correct john they do.

[didahdit]

Also, who told you to expect 15mb? That's an unrealistic figure given that you weere previously only at 6mb.

I've just remembered where I got that figure from - and it's still saying the same.
IDNet Broadband Availability Checker.  Enter your phone number.

TBH I'd be happy with the 12 meg IDnet said I would get in their Order Completion e-mail but 3 meg is a bit of a downer.


Bob

[didahdit]

What happens if you disconnect that and power it down?

Phone dissed and unplugged (got to redo the recording now!)  No significant difference - seee here - first  without tele.  The second is one taken some time earlier today with phones
System Up Time 215:10:10
Port    Status    TxPkts    RxPkts    Collisions    Tx B/s    Rx B/s    Up Time
WAN    PPPoA    1142    1209    0    1479    2281    00:03:17
LAN    10M/100M    5095139    4793755    0    3932    1426    215:10:01
WLAN    11M/54M/270M    0    0    0    0    0    05:08:30

ADSL Link    Downstream    Upstream
Connection Speed    3547 kbps    828 kbps
Line Attenuation    27.0 db    12.3 db
Noise Margin    30.1 db    7.4 db

System Up Time 213:58:49
Port    Status    TxPkts    RxPkts    Collisions    Tx B/s    Rx B/s    Up Time
WAN    PPPoA    104009    137362    0    3067    13312    02:33:40
LAN    10M/100M    5068052    4766050    0    3939    1424    213:58:40
WLAN    11M/54M/270M    0    0    0    0    0    03:57:09

ADSL Link    Downstream    Upstream
Connection Speed    3547 kbps    828 kbps
Line Attenuation    27.0 db    12.3 db
Noise Margin    29.9 db    8.6 db

Bob

[MisterW]

With that high a downstream SNR I would normally suggest it had been 'banded' BUT I didn't think 3547 was at the top of any band. IIRC the relevant bands are :- 1472Kbps - 3072Kbps & 2272Kbps - 4544Kbps.

[john]

That is correct john they do.

Thanks pctech.

Do you know if they only degrade if they are used or do they degrade over time anyway. Also why do they degrade and is it not possible for them to make ones that don't degrade ?

[Steve]

I agree it's not a banding I'm aware of,however something is limiting the sync an allowing the 'excess' SNR what do support say about this and your router stats?

[didahdit]

I just swapped the filter for the one on my plan 1a/extension  (which has been disconnected all morning cos I'm using the test jack)  Results are similar.

I haven't raised it with support yet - I suppose I'll have to.  Don't like to bother them with niggling problems. 

Bob 

[Lance]

I think an email to support is going to be best, providing them the router stats and BT speedtest, or just point them at this thread.