SNR drop from 6PM onwards ?

deadl0ck

Hi all,
I'm having trouble with my Ericom DSL speeds. I'm on a 7MB package and I get around 5 - 5.5 Meg during the day pretty steady.
At night from about 6PM onward it drops to 0.5 Meg or even below (see some of my test results here)
I've tested this speed on the master socket with nothing else connected to my network to verify the speeds.

Eircom are looking into it for a month now and they are going to try me on a new port on the exchange next but basically my line checks out fine and I'm just less than 3 miles form the exchange (my Exhange is Moyvore and is not NGB enabled but it's connection to the main fibre line as the fiber network runs to it between Mullingar and Athlone so I'm guessing the backhaul isn't an issue)

Anyhow - on to my point - I've been monitoring the connection myself and looking at my SNR to see if it's related.
My SNR is around 6db but if I reboot the modem in the morning it goes to about 10 or 11db.
It gets a bit worse during the day but really drops from 6PM onwards and seems to stay low around 6db from then on (unless I reboot the next morning - see pics below)

My questions are :
(1) Could this increase in SNR have a bearing on the speed (bear in mind I've seen 6db during the day and still had good speeds) ?

(2) Any idea as to why I'm experiencing the drop in SNR like this in the evenings ? (Could it be the router - I've just rebooted it and SNR is gone from 6 to 7 and my speed is gone up to 1.5MB - but sometimes a reboot makes no difference)

Here's a look at my speeds this morning and this evening (the jump in SNR is after a modem reboot):


and

kaizersoze

You could try another router just to rule it out if nothing else. It would be my first port of call.

Any household activity begin around that time? eg. people arriving home and using the phone? Neighbours with workshops?

ED E

Yes, there is a reason. Its called crosstalk. Most connections will read a dB or two lower at peak times.

deadl0ck

kaizersoze wrote: »

You could try another router just to rule it out if nothing else. It would be my first port of call.

Any household activity begin around that time? eg. people arriving home and using the phone? Neighbours with workshops?

Not in my house anyhow. Could be neighbours, but it's a very sparsely populated area - my daughter starts school next year and there are going to be 6 kids in the class - that gives you an idea of how rural it is...

Yes, there is a reason. Its called crosstalk. Most connections will read a dB or two lower at peak times.

Maybe that's' it then but it doesn't really pick back up again and hand down around 6 or 7db unless I restart the router - I might try another router - I have a Netgear I could try (currently on a TP-Link W8960)

I guess it could be congestion but 10% of my normal speed and even lower - is congestion normally that bad (he asked hoping it's something else that's solvable....) ?

deadl0ck

Hmmm.....I rebooted the modem again this morning and SNR went from 8 up to 11 and it's stayed like that since ( Should the modem detect that SNR is less and retune itself ??) :



Incidentally my full stats are as follows - I'm new to all this so can anyone tell me if these are good / bad ?:

ED E

SNR is an estimation. Its also done over an interval so often you'll see X just after a sync and then it'll bed down as it takes more readings and averages out.

First step would definitely be to try another modem. What it sounds like is happening is your SNR is dropping at night due to increased crosstalk and error rate is spiking meaning the effective throughput drops sharply as half the data sent is being corrupted and needs to be error corrected. Actually no, I just re-read the OP. If you're on a 7Mb package and not an 8 thats an old exchange. It could well be a backhaul problem then, but isnt necessarily.

If you're testing at 5.5Mb down its likely a 6Mb profile. Call eircom tech support and ask them to profile you down 1Mb to 5Mb(itll test at 4.x). If the connection maintains its speed that night, then its crosstalk. If not its likely backhaul. All assuming the modem is working ok. Speaking off, what is it? If its graphing SNR I suspect its decent.

deadl0ck

I'll try a different modem and see how it fares - I'd even consider getting a new one as the one I have is a few years old anyhow (looking at this one as it supposed to be good for low SNR and you can manually tweak it also...)

Well I know the Moyvore exchange is connected to the ericom fibre network (can't find the map right now but there was one where it shows the fibre network - also the engineer confirmed it) but the exchange itself has not been NGB enabled so I'm guessing it's the equipment in the exchange thaqt may be overloladed as opposed to the internet connection to the exchange (if that makes sense).

The modem is a TP-Link W-8960 and I'm using the "RouterStats Lite" program (here) to get the graph

Freddy Smelly

call tech support and ask if your line is on an NGN exchange or the older type exchange.

if it is on NGN then it should not be affected by contention
if it is on an older exchange then it might explain why you get poor speeds.

also is the power adapter for your modem plugged into a gang lead or directly into wall socket?

crappy gang leads can increase noise levels

also if you have it in a gang lead is there an iphone charger plugged into the same gang lead? if yes unplug the iphone charger.

iphone chargers are poorly made and add tremendous electrical noise which can travel to the power adapter of the modem and into the modem resulting in crappy snr margins.

deadl0ck

call tech support and ask if your line is on an NGN exchange or the older type exchange.

if it is on NGN then it should not be affected by contention
if it is on an older exchange then it might explain why you get poor speeds.

Will do when I get a chance - is this different from NGB ?

also is the power adapter for your modem plugged into a gang lead or directly into wall socket?

Directly into wall socket

crappy gang leads can increase noise levels

also if you have it in a gang lead is there an iphone charger plugged into the same gang lead? if yes unplug the iphone charger.


iphone chargers are poorly made and add tremendous electrical noise which can travel to the power adapter of the modem and into the modem resulting in crappy snr margins.

OK - but the same sockets are plugged in and turned on all day and don't get these problems during the day - consistently it starts to go downhill around 6 (see graph above).
I tested with the router directly into the master socket and all other plugs / sockets turned off in the room with the laptop running on battery and connected with an ethernet cable to the router and get the same results

Actually - here are the results from this evening - the drop outs were when I rebooted to test some things:

deadl0ck

Ah - here's the map - exchanges is on the line but it's not been upgraded

Freddy Smelly

nga = efibre
ngb = adsl2+
dslam = older exchange adsl

deadl0ck

Freddy Smelly wrote: »

nga = efibre
ngb = adsl2+
dslam = older exchange adsl

It must be dslam so.

deadl0ck

Actually my main concern is my speed drop in the evenings.
(I'm following the SNR as a potential casue)
My speeds go from a steady 4.5 / 5 Meg during the day down to about .5 meg (or sometimes slower) in the evenings.

Is this congestion ? I didn't think it would get that bad...

ED E

deadl0ck wrote: »

Actually my main concern is my speed drop in the evenings.
(I'm following the SNR as a potential casue)
My speeds go from a steady 4.5 / 5 Meg during the day down to about .5 meg (or sometimes slower) in the evenings.

Is this congestion ? I didn't think it would get that bad...

Its possible, very possible.

deadl0ck

ED E wrote: »

Its possible, very possible.

Ah sh1te...hopefully I might get a better result when they change me to a different port next week (supposedly)....