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[simon3030]

Hi, new to ADSL fiddling...I am on a copper connection to my ADSL only (rural) exchange, 3.1 km away, and regularly get 2.5 max Mbs, via my TalkTalk LLU connection. My exchange is ADSL Max enabled, but not yet ADSL2+ - and no date for that.
Can I improve my speed?
Router stats:
ADSL Statistics

Mode:   ADSL2
Type:   ANNEX_A
Status:   Showtime
 
                                       Downstream          Upstream
Rate (Kbps):                       2938 kbps          787 kbps
 
SNR Margin (dB):                 11.1                   8.8
Attenuation (dB):                  54.0                   32.6
Output Power (dBm):             0.0                   12.3
 
Super Frames:                  34423575          34423575
RS Correctable Errors:       15353                65528
RS Uncorrectable Errors:   2372                  65513
 
HEC Errors:                      18653                0
Total Cells:                       55893               60497
Data Cells:                       110390451        58649681
Bit Errors:                                0                    0
It's a DLink DSL-2740R, as supplied by TalkTalk, and seems pretty reliable, but occasionally I have real issues with download speed, and just wondered....

Pls advise if more info needed, thanks.

[HPsauce]

My exchange is ADSL Max enabled, but not yet ADSL2+

Mode:   ADSL2

Are you sure?
(not that it makes much difference at your line length)

[Oranged]

Are you sure?
(not that it makes much difference at your line length)

Think simon3030 meant BT's WBC......his connection is TT LLU.

First off the router is only connected at ADSL2 and not ADSL2+
Second the SNRM is causing the low sync speed and this together with the ADSL2 connection may indicate an exchange fault.

If you have a NTE5 main socket then unscrew the lower half and plug the router into the test socket which you'll find inside then post back with those stats.

On a 54dB attenuation the router should sync at around 4000kbps on ADSL2+. But as HPsauce says there will be little difference on ADSL2. So there is a line problem of some sort.

[HPsauce]

A line problem or internal wiring problem; but the stats from the Test Socket will illuminate.

The above-average SNRM suggests errors have been detected and are possibly being "managed" but I'm not familiar with how TT LLU does that compared to say BT's DLM.

I don't think ADSL2+ would perform noticeably better than ADSL2 anyway, if at all, on this line.
Also, I seem to recall that initially TT LLU was "restricted" to ADSL2 anyway and that the higher speeds were optional (at a cost?) or awaited equipment upgrades.

A brief description of the internal wiring, sockets, extensions etc. would be useful too.
The type (e.g. plug-in or "proper" BT cabling) of extension wiring is significant. 

[burakkucat]

As one with TalkTalk as his CP via a fully LLU'd line, I can add some detail regarding the TT DLM.

The default target SNRM is 6 dB but if the modem/router is not left on 24/7, the SNRM will rise to about 12 dB for those cases where the modem is powered on in the morning and powered off overnight.

In the four and a bit years that I have been with TT, I have used three different modem/routers, each successive one a better performer than its predecessor.

(1) A Huawei SmartAX MT880, supplied by TT in 2007.
(2) A Netgear DG834Gv5, purchased new via Amazon.
(3) A 2Wire 2700HGV (a.k.a. a BT Business Hub, Version 2.0), purchased new via eBay.

(For completeness I also have a 2Wire 2701HGV-C (a.k.a. a BT Business Hub, Version 3.0), purchased new via eBay, tucked away in my grotto.)

The original TT equipment in my exchange, EABSE, was 20CN ADSL. Eventually it was upgraded to 21CN and ADSL2+. The first I knew of that upgrade was when I noticed my downstream throughput had dropped, whilst the upstream had increased. At that point I replaced modem/router (1) with (2). Eventually I set the DG834G to "ADSL" mode (i.e. G.Dmt) rather than its default "auto" and I managed to get back my downstream throughput. Unfortunately, the v5 DG834G has a Conexant chipset whilst the DSLAM (manufactured by Hauwei) uses a different chipset. Eventually, after months of suffering from "hours of darkness" RFI, a BT80B-RF3 was fitted and I replaced modem/router (2) with (3). This 2Wire 2700HGV is left on continuously. That is the background information finished -- so those at the back can now wake-up!

From Kitz' ADSL Line and Exchange Checker --

Line Check Results
For Telephone No:    01284nnnnnn
Postcode:    IP32 XXX
Phone & Postcode search OK
   
Exchange Information
Exchange: Bury St Edmunds    BT Code: EABSE
Location: Whiting St,    IP33 1NS
Distance:-    Direct:          1.8 km
     (appx)*    By Road:    2.41 km

Status    
ADSL enabled:    June 30, 2001
DSL Max enabled:    March 31, 2006
SDSL enabled :    Enabled
21CN due : (PSTN)    N/A
21CN WBC (Broadband)    Enabled
Broadband Access†    Market 3

From the 2Wire 2700HGV --

Current DSL Connection:
   Down    Up
Rate:    5446 kbs    1021 kbs
Max Rate:    5446 kbs    1048 kbs
Noise Margin:    1.5 dB    6.4 dB
Attenuation:    50.2 dB    27.7 dB
Output Power:    19.6 dBm    12.4 dBm

Protocol:    G.DMT2+ Annex A
Channel:    Interleaved
DSLAM Vendor Information    Country: {46336} Vendor: {IFTN} Specific: {50801 }
ATM PVC:    0/38

Rate Cap:    5446 kbs
Attenuation @ 300kHz:    50.2 dB
Uncanceled Echo:    -18.1 dB    Ok
VCXO Frequency Offset:    -11.3 ppm    Ok
Final Receive Gain:    25.5 dB    Ok
Impulse Noise Comp. Tones:    0    Ok
Excessive Impulse Noise:    0    Ok

Downstream Rate Cap:    8192 kbps
Downstream Atten. at 300kHz:    43.7 dB
Uncancelled Echo:    -18.1 dB    Ok
VCXO Frequency Offset:    -11.3 ppm    Ok
Final Rx Gain:    25.5 dB    Ok
Impulse Noise Comp. Tones:    0    Ok
Excessive Impulse Noise:    0    Ok
Impulse noise protection:    0.90
Delay of latency path:    11.49 ms

Note how low my downstream SNRM has dropped due to hours of darkness RFI. The 2Wire holds sync well and the connection is perfectly usable. In twelve hours time the D/S SNRM will be back to about 5.8 - 6.1 dB.

I think I've typed quite enough, so please make use of the above statistics for a typical middle length, not long, TT fully LLU'd line.

[HPsauce]

The default target SNRM is 6 dB but if the modem/router is not left on 24/7, the SNRM will rise to about 12 dB for those cases where the modem is powered on in the morning and powered off overnight.

Very interesting, so another piece of information is required, i.e. what power on-off pattern is the router used in?

[burakkucat]

To complete the picture of my connection (for those who may wish to use the details as an example), here are my statistics during daylight hours. Note that the D/S SNRM has risen back to 6.0 dB and the U/S SNRM has dropped to 6.1 dB.

Current DSL Connection:
   Down    Up
Rate:    5446 kbs    1021 kbs
Max Rate:    5446 kbs    1032 kbs
Noise Margin:    6.0 dB    6.1 dB
Attenuation:    50.2 dB    27.7 dB
Output Power:    19.7 dBm    12.4 dBm

Protocol:    G.DMT2+ Annex A
Channel:    Interleaved
DSLAM Vendor Information    Country: {46336} Vendor: {IFTN} Specific: {50801 }
ATM PVC:    0/38

Rate Cap:    5446 kbs
Attenuation @ 300kHz:    50.2 dB
Uncanceled Echo:    -18.1 dB    Ok
VCXO Frequency Offset:    -11.3 ppm    Ok
Final Receive Gain:    25.5 dB    Ok
Impulse Noise Comp. Tones:    0    Ok
Excessive Impulse Noise:    0    Ok

[roseway]

@BK:

I think your upstream connection is uncapped rate adaptive in the same way as the downstream, with a target noise margin of 6 dB. So after a re-sync it will connect with a noise margin of 6 dB at the highest speed it can achieve for that noise margin.

[burakkucat]

Thank you for confirming my suspicions, Eric. I was wondering if that was the case, having a Rate 1021 kbps and a Max Rate 1032 kbps under the Up column of my statistics.

As both the OP (Simon) and myself are users of a TT LLU'd service, it is worth bearing that in mind.