2700HGV not offering the performance over long line

[shpub]

I live a long way from the exchange - 6km- and while switching to IDNET from Tiscali has helped a lot with speed - 750kb from 288kb - I am trying to get as much as possible. I was part of the long reach BT trial in 2003/2004 because of the length!

I've removed the internal telephone connections, used the ADSL face plate etc but the problem seems to be with ADSL2+ vs ADSL.
If I force ADSL with a 834G v5 I can get 890/608 connections. If I use a 2700 v6 it connects at ADSL2+ but only gives 596/500 which is slower.

I can't find a way of forcing the 2700 into a ADSL connection which I think will give a better performance over the long lines as with all my modems, using ADSL2+ decreases the connections speed.

Any ideas/solutions/tips?

[Steve]

 

I'm not a 2700 user . I'm sure you'll get an authoritative answer before too long.

[Simon]

 

And, what Steve said. 

[Ray]

 

[Rik]

Hi and welcome to the forum.

I'd suggest you have a word with support and get them to switch you to Max modulation, it's the easiest way.

[MisterW]

I can't find a way of forcing the 2700 into a ADSL connection which I think will give a better performance over the long lines as with all my modems,

Nope, AFAIK there is no way to force the ADSL modulation mode on a 2700. They usually give very good performance when left to their own devices
but are NOT very configurable. 

[shpub]

Thanks for the replies. I've contacted support re the modulation.

Interestingly enough I found that the ADSLNation face plate knocked about 150kbs off the sync rate compared to the standard BT one. This was on both the 834G with ADSL and the 2700 with ADSL2+.

The 2700 is the only router that connects with ADSL2+.

I'll do some MW radio noise checks and see if that explains the difference. 

[Tacitus]

Interestingly enough I found that the ADSLNation face plate knocked about 150kbs off the sync rate compared to the standard BT one. This was on both the 834G with ADSL and the 2700 with ADSL2+. 

TBH that doesn't surprise me since they contain more electronics than the BT (or Clarity) versions.  Technically I believe they are an 'active' filter rather than a 'passive' one, although someone more knowledgeable will probably correct me.

I've never really understood why people are so enamoured with the ADSLNation version over the BT (or Clarity since they are most likely both made by Pressac) model.  I'm not saying they are no good, but I'm not convinced that in practice they are 'better' in any significant way.  Each to their own I suppose 

[Den]

What time of day are you trying to re-sync? It's better to do it during the week and early in the morning IMO. If I tried at a weekend or later in the day I will always sync at a lower speed. I am about two mile from my exchange and sync at about 7349 at the moment (using a 2700hgv). By the way welcome to Idnetters    

[shpub]

As with a lot of things ADSL, there seems to be a bit of  black art to everything. I had seen good reports about the ADSLnation and thought it was worth a try. The fact that it doesn't work for me in this case doesn't mean that it is an awful product.

I usually resync early in the morning and the 834G seems to be solid at that time. I resynced a couple of times yesterday and it came up with 898/608 constantly.

I do cry a bit when I see comments of "I only synced at 7536" - as I am currently thinking that 750kbs is absolute luxury. To be honest as the 2700 was measuring 78db attenuation, I have to be thankful that it works at all!

I'll keep you updated.

[Rik]

Please do.

[Polchraine]

ADSL2+ will normally give slower speeds only longer (higher attenuation) lines - it is a known characteristic of the modulation.

As suggested, get Tech Support to sort it out and then see what you get from the line.  At a guess it will be better than the DG834 once sorted.

Out of interest, what are the full line stats from the 2700?   Can you post the data from:   http://192.168.1.254/xslt?PAGE=C_1_0

and the last line from Training History on:  http://192.168.1.254/xslt?PAGE=C_5_3

[shpub]

I've just been switched over and the 2700 is connecting in G.DMT mode and my sync speed has gone up. I'm just waiting for the training period/IP Profile to come up but it looks like I could be in the 1 Mbps range which I would have not believed!

There is no Radio MW noise at the master socket but quite a bit by the Mac where the modem is sitting next to several NAS drives. I'll move the 2700 to the master socket and either link wirelessly or by Ethernet cable.

The only other thing I am thinking of trying is a using a non switch mode PSU on the 2700 as I have seen that this can help things as well.

Current DSL Connection:
                     Down          Up
Rate:               1152 kbs   288 kbs
Max Rate:       1272 kbs   788 kbs
Noise Margin:   4.0 dB   19.0 dB
Attenuation:   63.0 dB   31.5 dB
Output Power:   15.9 dBm   12.2 dBm


Protocol:   G.DMT Annex A
Channel:   Fast
DSLAM Vendor Information   Country: {46336} Vendor: {TSTC} Specific: {4101 }
ATM PVC:   0/38

Rate Cap:   1272 kbs
Attenuation @ 300kHz:   63.0 dB
Uncanceled Echo:   -10.4 dB   Ok
VCXO Frequency Offset:   -6.0 ppm   Ok
Final Receive Gain:   34.5 dB   Ok
Impulse Noise Comp. Tones:   0   Ok
Excessive Impulse Noise:   0   Ok




Training data:

Time   Line      Rate   Max1   Max2   Max3   Mgn1   Mgn2   Attn   Pwr   CRCs   FECs   INP   DLY         
BST   1      1152   1280   1276   1276   4.4   4.0   73.0   16.0   1040   0   0.00   0.25   

Rate   Max   Mgn   Attn   Pwr  CRCs   FECs   
288   788   19.0   31.5   12.2   0        0

   Mode                 Vendor   State          Exit Code   Echo   VCXO    Rx Gain   INC Tones
   G.DMT Annex A   TI   236/104   N/A          -10.4   -6.0    34.5           0

[Rik]

My stats on ADSL2+ are 63db attenuation, 6.1db noise margin and 4269 sync, that's also from a 2700. The attenuation increased, inevitably, when I moved to ADSL2+ due to the higher frequencies used. Previously it was 56db. I think your line is clearly only going to support ADSL for the time being, so it might be worth trying a different router if you can to try and improve the sync speed - though the 2700 is particularly good on long lines. Other than that, if you use a DECT phone, it might be interesting to turn that off and see if speeds improve, similarly, disconnect any Sky box etc.

Sadly, I fear, your ultimate fate lays with BT.

[shpub]

I think you are right about my fate being with BT.

However Tiscali/TalkTalk/Opal were adamant that I could only get 288 which is one of the reasons I switched. On a more positive note, I now have several times the speed I had before and it is just about fast enough to watch iPlayer so I am very pleased.

I'll try the Dect phone idea.

Any other router you would suggest? Bear in mind the 2700 was only 99p + postage!

[Rik]

Draytek or Speedtouch, but the former, in particular, is not cheap. However, ask around your friends and see if they would let you try their routers - just don't change more than once a day.

[MisterW]

Rate:               1152 kbs   288 kbs

That looks like a fixed 1Mb connection to me, the 288 upstream is the giveaway!
But then again with only a 4db downstream SNR that's probably just as well, as a ADSL1 MAX may well synch slower.

[jameshurrell]

Yep, i'd agree MisterW... it's a fixed 1Mbps connection....

Also, although I love Drayteks (had several 2600s over the years), they are not fond of long lines (in my experience).

[Polchraine]

Sadly, I fear, your ultimate fate lays with BT.

A bit unfair - even the amount BT invests in R&D is not enough to change the laws of Physics!

[Polchraine]

shpub ...

Now you have an improved speed you should try to minimise resyncs whilst getting a reasonably high speed to ensure the system does not force a higher margin at sync.

I am purely on BT - but at present if I resync at around 20:30 to 21:00 I get 6350 (ish) which translates to a 5500 profile on BT.   That is with a 3dB margin.   As the evening goes on the margin drops to 0dB and occasionally to -0.5 but the line holds up.   During the day it will climb back up past 3 to 6, 7 or even 8dB but if I resync then it will drop out during the night and my sync speed will be under 6000  and a profile of 4500/5000.   

Try a late evening resync - say 20:00 / 20:30 and use RouterStats lite to monitor the connection and see if the line stays synced for 24 hours and what the lowest margin is.

[Rik]

Sound advice. 

[MisterW]

Now you have an improved speed you should try to minimise resyncs whilst getting a reasonably high speed to ensure the system does not force a higher margin at sync.

Hang on chaps... If its a fixed 1Mb connection its either going to synch at 1Mb or not at all! If it synchs then you will get whatever SNR margin the line is capable of at the time, higher in the morning and lower at night.

[Rik]

Good point. 

[Polchraine]

Hang on chaps... If its a fixed 1Mb connection its either going to synch at 1Mb or not at all! If it synchs then you will get whatever SNR margin the line is capable of at the time, higher in the morning and lower at night.

Is it?    In the original post it states:   

I've removed the internal telephone connections, used the ADSL face plate etc but the problem seems to be with ADSL2+ vs ADSL.
If I force ADSL with a 834G v5 I can get 890/608 connections. If I use a 2700 v6 it connects at ADSL2+ but only gives 596/500 which is slower.

That is not a fixed 1Mb  -   so unless the OP has now been put on a fixed connection rather than an ADSL2 he should be able to sync at the best possible rate.

[Rik]

I know, but at:

http://www.idnetters.co.uk/forums/index.php?topic=22013.msg530968#msg530968

the OP quotes 1152/288 as his sync speed, which would appear to be a fixed rate 1M service.