A little advice please

[zappaDPJ]

One of the people I've brought to IDNet is now connected but the line speed seems a little low. I'm not the world's best at interpreting modem stats so I'd be grateful for opinions. The modem is a little long in the tooth so the stats had to be retrieved via Telnet.

Modem State        : UP
Operation Mode    : G.DMT AnnexA [POTS overlay mode]
Channel mode      : Interleaved
Number of resets  : 1

Vendor                :            LOCAL                        REMOTE
Country                :              0f                                   b5
Vendor                :             ALCB                            TSTC
Vendor specific    :              0000                             0400
Standard revision    :             01                                 01

                                       Downstream                Upstream
Margin (dB)                            15                               17
Attenuation (dB)                     46                                27
Output power (dBm)               19                                12

Available bandwidth               Cells/s                        Kbits/s
Downstream                           8226                          3488
Upstream                               1056                           448

Transfer statistics                  Cells                           Kbit
Total since power on 
Downstream                         1224426                    519156
Upstream                             247184                     104806
Current connection
    Downstream                     1224408                   00519148
    Upstream                          247184                      104806

Errors received        FEC : 1055
                             CRC : 44
                             HEC : 37

No near end or far end failures.

[kinmel]

It is syncd with an SNR of 15, we expect a line to sync with a SNR of 6 in normal circumstances.

Using Mr Saffron's (of Thinkbroad fame ) calculator your figures suggest a sync rate of 5888 is expected which equates to a 5meg connection.

It is likely that BT have set the SNR to 15 because of line problems, but tell us about the phone sockets and extensions at the house and we may be able to improve it.

Idnet may be able to get BT to reduce the SNR back to 6 once we know the conditions at the house are correct

[Rik]

The noise margin upstream seems a little low for the attenuation too, so my immediate thought is that it's a noisy line.

[zappaDPJ]

Cheers. I've gone through all the obvious things like ensuring the router is close to the BT socket and not running from an extension (which made no difference) and the wiring is being checked for a ring wire. The infrastructure is quite old as there is no test socket on the face plate but it's likely to be quite sound with extensions properly wired and filtered.

My immediate thoughts were line quality as well but I have to say it sounds pretty clear to me and the distance from the exchange in terms of walking distance is certainly under two miles.

[Rik]

You can often double the 'crow flies' distance when it comes to cable runs, though. The attenuation suggests about 4.5km.

[zappaDPJ]

In a straight line the property is listed as 1.65 km from the exchange.

[Rik]

Possibly it's aluminium cable then, or just in poor condition.

[sparky]

I'm no expert, but I did improve mine.............

You obviously have extensions. Properly wired or not, these can add noise. I also found that adding splitters also decresed my SNR.

You need to plug the router into a splitter, directly into the master socket, with NO extension wiring at all connected. Then see what you get. If it improves, you can try reducing extensions to an absolute minimum and connecting them to the master with NO bell wire. That acts as an aerial for noise. The bell signal is generated by a splitter, so your extensions need only be 2-wire.

I did all that and increased my speed my 1Mb.

Sparky.

[zappaDPJ]

Thanks, the next time I'm there I'll take a look myself and see if there any improvements to be made.

[Rik]

You are, of course, somewhat hampered by the lack of an NTE5, in theory.  

[zappaDPJ]

Indeed and if I was to go to the trouble of theoretically putting one in, I'd probably do it in my own home first... in theory 

[Rik]

Precisely.

[sparky]

There are ways.

I have a single master socket in the hallway. Into the front of that socket is plugged an extension cable that runs through a stud wall and is about 20cm long into a junction box. The bell wire stops there.
Then using round twisted pair cable, I have run a two wire extension to the study into an extension socket. I have plugged in 1 splitter there. The ADSL modem plugs in there, so does the Telephone.

That was the minimum I could get down to. Even had to pay full price for Sky + as I refuesd to have an additional extension socket in the lounge.

Haven't had to remove the master socket from the wall at all. Unplug the connector from the  front of the master socket and everything is disconnected.

Sparky.

[Rik]

You can 'buy out' the telephone clause from Sky for £25, Sparky.

[sparky]

Yes, but you can't get the box for £99 !!

or at least, I couldn't   

[Rik]

That's rough, I thought you just had to pay £25 to waive the phone clause.