Low speeds but large SNR margin?
Hi all,
I'm a long time (7+ years) Plusnet member, and for the vast majority of that time I've had a stable line at around 2Mb - Not great, but about the best I can expect as I'm on a relatively long line.
Recently, though I found my speed had dropped to sub 1Mb, which is obviously not great. I thought that this was due to an old internal telephone extension, which I've removed. I've now been plugged into my BT test socket for the past 3-4 days and I'm still only getting 1376Kbps downstream, which only seems to translate to a 750Kbps IP profile
The odd thing is, my upstream is synchronising at a solid 832Kbps - I would have expected that to be much lower, given that the downstream is so slow?
My line stats also seem to indicate that I could achieve a higher speed - I have a SnR margin of 14db and a line attenuation of 44db, which seems to have been fairly stable over the past 3 or 4 days that I've been monitoring.
I'm just wondering if anyone has any ideas before I raise a support ticket? In the past while I was enjoying a huge(!) 2Mb connection my SnR margin was hovering around 6db, so I wonder if this is the key to my current slow speeds? Can the target margin be dropped by Plusnet / BT?
I'm a long time (7+ years) Plusnet member, and for the vast majority of that time I've had a stable line at around 2Mb - Not great, but about the best I can expect as I'm on a relatively long line.
Recently, though I found my speed had dropped to sub 1Mb, which is obviously not great. I thought that this was due to an old internal telephone extension, which I've removed. I've now been plugged into my BT test socket for the past 3-4 days and I'm still only getting 1376Kbps downstream, which only seems to translate to a 750Kbps IP profile
The odd thing is, my upstream is synchronising at a solid 832Kbps - I would have expected that to be much lower, given that the downstream is so slow?
My line stats also seem to indicate that I could achieve a higher speed - I have a SnR margin of 14db and a line attenuation of 44db, which seems to have been fairly stable over the past 3 or 4 days that I've been monitoring.
I'm just wondering if anyone has any ideas before I raise a support ticket? In the past while I was enjoying a huge(!) 2Mb connection my SnR margin was hovering around 6db, so I wonder if this is the key to my current slow speeds? Can the target margin be dropped by Plusnet / BT?
Thanks for the reply,
My router is currently plugged into the test socket - I plugged it in there 3 or 4 days ago. The stats mentioned above were taken while it was plugged in there (just this evening). The complete line stats are:
noise margin upstream: 10 db
output power downstream: 16 db
attenuation upstream: 30 db
noise margin downstream: 14 db
output power upstream: 12 db
attenuation downstream: 44 db
The odd thing is that I seem to be getting a good upstream connection ( syncing at 832kbps, actual throughput 650kbps ish), which I've confirmed via the BT Speedtester - It just seems to be that the download has dropped way off and is only just higher than the upstream at about 720kbps ish.
I suspect that the issue is related to the 14db noise margin - I'm pretty sure that when I was getting consistent 2Mb+ speeds the noise margin was much lower.
The other consideration is that I'm on the 21CN network apparently - Not sure if that has any bearing?
Any help or suggestion would be greatly appreciated
My router is currently plugged into the test socket - I plugged it in there 3 or 4 days ago. The stats mentioned above were taken while it was plugged in there (just this evening). The complete line stats are:
noise margin upstream: 10 db
output power downstream: 16 db
attenuation upstream: 30 db
noise margin downstream: 14 db
output power upstream: 12 db
attenuation downstream: 44 db
The odd thing is that I seem to be getting a good upstream connection ( syncing at 832kbps, actual throughput 650kbps ish), which I've confirmed via the BT Speedtester - It just seems to be that the download has dropped way off and is only just higher than the upstream at about 720kbps ish.
I suspect that the issue is related to the 14db noise margin - I'm pretty sure that when I was getting consistent 2Mb+ speeds the noise margin was much lower.
The other consideration is that I'm on the 21CN network apparently - Not sure if that has any bearing?
Any help or suggestion would be greatly appreciated
Are you talking about poor sync speeds or the results you get on speed tests?
Apologies if I wasn't clear in my initial posts
The problem is that after 7 years of getting a relatively stable 2Mb downstream, I'm now finding that I'm only getting a 1372Kbps downstream sync, which gives me an IP Profile of 750Kbps and a throughput via the BT speedtester of about 730Kbps. My upstream sync however is at 832Kbps, with a throughput (tested via the BT speedtester) of about 650kbps-ish.
It seems really odd that my downstream sync would be so slow when my upstream is so good. Also my line stats (posted above) seem to suggest that the attenuation is OK and there is some noise margin still "available".
I'm just wondering if there's anything else I can do at my end, before raising a ticket, as I believe that currently tickets are taking a long time to be looked at / actioned. I've already removed all internal extension wiring and I'm plugged directly into the BT test socket.
Any ideas?
The problem is that after 7 years of getting a relatively stable 2Mb downstream, I'm now finding that I'm only getting a 1372Kbps downstream sync, which gives me an IP Profile of 750Kbps and a throughput via the BT speedtester of about 730Kbps. My upstream sync however is at 832Kbps, with a throughput (tested via the BT speedtester) of about 650kbps-ish.
It seems really odd that my downstream sync would be so slow when my upstream is so good. Also my line stats (posted above) seem to suggest that the attenuation is OK and there is some noise margin still "available".
I'm just wondering if there's anything else I can do at my end, before raising a ticket, as I believe that currently tickets are taking a long time to be looked at / actioned. I've already removed all internal extension wiring and I'm plugged directly into the BT test socket.
Any ideas?
I was wondering if he was still on 20CN but with Max Premium which gives the 832kbps sync
Hi Alphaseven,
Your profile is WBC 8M/Uncapped/15dB/Interleaved (ADSL) on 21cn. I would expect to see better speeds for your attenuation. Have you tried a different filter or router? Is the filter directly into the test socket and not via an extension?
Jojo
Your profile is WBC 8M/Uncapped/15dB/Interleaved (ADSL) on 21cn. I would expect to see better speeds for your attenuation. Have you tried a different filter or router? Is the filter directly into the test socket and not via an extension?
Jojo
Many thanks for looking into this Joanne.
The router is plugged directly into the BT test socket, and has been for about 5 days now in an effort to rule out any internal wiring issues. I also tried a different filter, but it didnt make a difference to the line stats - They were almost identical with either filter.
The 15db figure in my profile that you mention in your post above - Does that refer to the signal to noise target? I was just wondering, because when I've checked my line stats in the past (while my connection was good) the signal to noise margin was around 6 - 8db, but now its 14-15db.
Could it be that the signal to noise target has changed for some reason, resulting in the slow speeds I'm seeing? Is there anything that can be done to get the signal to noise ratio back to where it was?
Any help is much appreciated
The router is plugged directly into the BT test socket, and has been for about 5 days now in an effort to rule out any internal wiring issues. I also tried a different filter, but it didnt make a difference to the line stats - They were almost identical with either filter.
Quote from: Joanne Hi Alphaseven,
Your profile is WBC 8M/Uncapped/15dB/Interleaved (ADSL) on 21cn. I would expect to see better speeds for your attenuation. Have you tried a different filter or router? Is the filter directly into the test socket and not via an extension?
Jojo
The 15db figure in my profile that you mention in your post above - Does that refer to the signal to noise target? I was just wondering, because when I've checked my line stats in the past (while my connection was good) the signal to noise margin was around 6 - 8db, but now its 14-15db.
Could it be that the signal to noise target has changed for some reason, resulting in the slow speeds I'm seeing? Is there anything that can be done to get the signal to noise ratio back to where it was?
Any help is much appreciated