What speed should I be getting?

[#1]

Hi all,
I've been on PlusNet's premier service for two years, which offers speeds of 'up to 2Mb/s'.
Now I've never got more than about 960kb/s (based on a number of speed test utils), and I'm wondering if this is down to the quality of the line itself, or if there's a setting somewhere which BT or PlusNet need to apply.
Also, there was talk a while ago about PlusNet upgrading everyone to 8Mb/s - is there something I need to do to get this applied to me, or is it already done and the line just won't support it?
For reference, I've included some stats from my router:
Us Rate (Kbps) 288
Ds Rate (Kbps) 1152
US Margin 19
DS Margin 7
Trained Modulation GDMT
LOS Errors 0
DS Line Attenuation 61
US Line Attenuation 31
Peak Cell Rate 679 cells per sec
CRC Rx Fast 1397
CRC Tx Fast 829
CRC Rx Interleaved 0
CRC Tx Interleaved 0
Path Mode Fast Path
Also the MTU is set to 1500.
Thanks,
Paul

[#2]

You are on a Fixed 1Mbs connection - IPStream Home 100 most likely - which will limit your speeds to the figure you have quoted.
Given your figures, DS Margin (SNR) of 7dB, line attenuation of DS 61dB, you are a long way from the exchange and unlikely to get anything faster even if you did upgrade to an ADSL Max up to 8Mbs connection. This is because ADSL Max works on a min DS SNR of 6dB and you are at that level already so no speed increase will be possible.

[#3]

Thanks for your reply Peter.
According to this site, http://www.samknows.com/broadband/exchange.php?ecode=LWHAT
my local exchange is approximately 1 mile away.
It doesn't strike me as being a particularly great distance - do you think there could be an issue with the line?
Thanks,
Paul

[#4]

Although your exchange may only be a mile away, it is possible that your line does take a more circuitous route.
However, the figures you have would suggest a line length at the limits of 1MB broadband, so at a rough guess would be around 5km long.  This certainly doesn't fit with the location of your exchange!
Standard troubleshooting would start with trying the router in the master socket, with all extension wiring unplugged to see if your SNR and attenuation improve.
Barry

[#5]

I was in a similar posistion to you Paul.  I was told all the usual stuff about line quality, line length etc.. and it didn't make any difference that all my neighbours could have faster broadband than me.  I  live about half a mile from my exchange.  The problem was a BT RF filter on my line which was killing my broadband, I also had an attenuation of 61db.  Do you live near any type of transmitter, if so you may have one on your line somewhere. Since this was removed last year I nearly always have connection speeds around 6meg.  Here is my original post.  http://portal.plus.net/central/forums/viewtopic.php?t=49830&highlight=

[#6]

Certainly worth a check, I've seen a few cases of RF filters over the years. Often they were put in years (sometimes decades) ago to enable the voice service to work and whatever they were filtering against no longer exists or is no longer an issue.

[#7]

How would one go about checking for RF filters? I'm also in a position where I get very low speeds (my IP profile is set to a disappointing 1000kps). My router stats seem to imply that a faster speed should be possible:
Downstream / Upstream
SNR Margin (dB):  4.7  21.0
Attenuation (dB): 31.5  27.0
Output Power (dBm): 11.9  16.4
Attainable Rate (Kbps): 1376  1060
Rate (Kbps) 1216  448
-- Frank.

[#8]

Given those stats you have major noise margin problem on your line not an RF filter problem which would affect the attenuation
Have you tried using the master socket - the connection behind the lower removable faceplate.
Are you sure that you don't have an unfiltered phone/Sky box etc. connected.

[#9]

I've only got 2 phone sockets in the house (it's an old house) and while I have Sky, the box isn't attached to a phone line. Where might I go looking for the master socket?

[#10]

It should be the first socket where the wire enters the house and if it is a modern master socket it looks like this http://www.wppltd.demon.co.uk/WPP/Wiring/UK_telephone/uk_telephone.htm

[#11]

Found it. The only other socket in the house (the one to which the modem is connected) is an extension originating from the master socket. Unfortunately my cables aren't long enough to connection directly to the master socket. Both have a splitter on. Would it be worthwhile getting an extension cable and running it to the master socket?
How should I read the values in my modem - am I looking for low or high?
Thanks for the help btw!
-- Frank.

[#12]

I know it will be a pain but can you temporarily move your computer closer to the master socket and check the results.
With respect to your numbers

Quote

Downstream / Upstream SNR Margin (dB):    4.7      21.0 Attenuation (dB):    31.5    27.0 Output Power (dBm):    11.9    16.4 Attainable Rate (Kbps):    1376    1060 Rate (Kbps)    1216    448

The thing to look at is the synch rate relative to the SNR margin.
Basically given your attenuation figure of 31.5dB with a noise margin of 4.7dB you should be seeing much higher speeds.
For a comparison these are my figures

Quote

Bandwidth (Up/Down) [kbps/kbps]: 448 / 3,776 Line Attenuation (Up/Down) [dB]: 25.0 / 51.0 SN Margin (Up/Down) [dB]: 19.0 / 9.5

I am getting much higher speeds but with a high attenuation as I am a long way from the exchange.
By way of explanation.
Attenuation is how much the signal loses power from the exchange to you - the higher the number the further you are from the exchange and is normally constant regardless of the synchronisation speed.
Noise margin or SNR is a measure of the amount of noise or interference on the line in relation to the signal and reduces as the synch speed increases (actually with DSLMax it is the other way round as the noise margin dictates the synch speed so improving the line noise will increase the synch speed)

[#13]

Thanks kryten1st , that looks promising.
I don't know of any transmitters nearby but I have identified a couple of suspicious boxes on my line.
One is where the cable comes in at the side of the box-room window.  This is a small box (3" x 2" x 1") without any markings or sockets - the cable just goes in one end and out the other.
The other is an unused Cable & Wireless box right next to the wall socket where my router is plugged in - I'm not sure if that could be affecting things.
I'll have a go with my screwdriver to see what these things are up to.
Paul

[#14]

Quote from: Oldjim

I know it will be a pain but can you temporarily move your computer closer to the master socket and check the results.

Right, that took a lot of cable juggling but I managed to make it reach in the end. Here are the values as connected through the master socket:
  Downstream  Upstream
SNR Margin (dB): 5.1  21.0
Attenuation (dB): 32.0  27.0
Output Power (dBm): 11.9  16.3
Attainable Rate (Kbps): 1152  1064
Rate (Kbps) 1024  448
They don't look massively different from before.

[#15]

Hi Paul
If you look at my original post, on page 2 smudgpop was having the same problem, he has a couple of pics of the nasty filter have a look to see if it looks like the box next to your socket.  It sounds like one to me but without seeing it coudn't say for sure.  Mine had BT80B-RF2 44/99 printed on the back.