High SNR

duggy · Feb 19, 2014, 18:56:23

Hi All,

I wonder if someone may be able to assist.
My connection is stuck at an SNR downstream of 15dB, and is perfectly stable 14.5-15.5. I contacted support a week ago, and they said they would request a profile reset, and asked me to keep my router switched on.
However the SNR has been at 15dB every day since, except for about one hour on the evening of the reset request when it increased to 16dB.
If the profile reset has occurred successfully what change in SNR should I be seeing?
I am on an ADSL connection if that affects anything.

Regards,
Duggy

Gary · Feb 19, 2014, 19:03:58

A line reset would put you back on 6dB. Normally they occur very fast (mine when on adsl were almost immediate or within 30mins but they can take 24 hours) If its back to 16dB you are having issues, a noisy line electrically can cause that as well as other faults. Have you checked your wiring, and tried swapping the router over and tried another filter? Also have you plugged directly into the test socket to see if that helps?

lozcart · Feb 19, 2014, 19:07:02

I'm sure you will need to force the router to reconnect before you see a drop in the target SNR, when you first reconnect the SNR you see is what has been set by the line management.

Gary · Feb 19, 2014, 19:09:49

Quote from: lozcart on Feb 19, 2014, 19:07:02
I'm sure you will need to force the router to reconnect before you see a drop in the target SNR, when you first reconnect the SNR you see is what has been set by the line management.

A profile reset does not need the router to be rebooted, it would drop out and come back up on its own. Rebooting it is not needed. unless you lost connection normally.

duggy · Feb 19, 2014, 19:12:37

Hi Gary

No I have not tried plugging in the test socket.
Yes I have tried a different filter and it does not seem to make any difference.
Sorry what do you mean 'swapping the router over'?
If it was a noisy line would I not see a large variation in the SNR when monitoring it with routerstats?

Thanks for your assistance.

Gary · Feb 19, 2014, 19:27:36

Quote from: duggy on Feb 19, 2014, 19:12:37
Hi Gary

No I have not tried plugging in the test socket.
Yes I have tried a different filter and it does not seem to make any difference.
Sorry what do you mean 'swapping the router over'?
If it was a noisy line would I not see a large variation in the SNR when monitoring it with routerstats?

Thanks for your assistance.

If you can, plug into the test socket there is a help section on the forum that will show you how to do that as log as you have a NTE5 and see what router stats say. If you can borrow another router to test that would help rule out your equipment as the cause, because if an engineer has to be called out and they find fault with your equipment you will get charged. Avoid the flat RJ11 cable that comes with routers if you can as well and use something more robust, twisted pair cables offer better protection from interference and you can get shielded cables too. Try and route cables away from power sources as well.

duggy · Feb 19, 2014, 20:20:44

I have just tried swapping the router from a Netgear DG834PN to an old Netgear DG834v2 and the SNR has gone from 14.5-15.5dB to 11-15dB, so is actually less stable. I have used the test socket in the past and will give that a try at the weekend.
I think I have other problems as well, as before swapping the router I tried running some speed tests and although the IP profile was 4.5Mbps I could only get a speed of 1.5-2.0Mbps.

Steve · Feb 19, 2014, 21:00:28

What is the downstream sync and attenuation and are you in adslmax or adsl2+?

duggy · Feb 19, 2014, 21:08:47

Hi Steve

I think it is just ADSl.
Sync is currently 5056Kbps, and attenuation is 38.
I have swapped back to the 834PN router.

Steve · Feb 19, 2014, 21:17:17

So if your on adsl you've lost a bit of downstream speed as it should be around 7000 kbps which fits with the elevated margin. It's likely to be interference somewhere and think the test socket worth a try, you need to check your router stats on re connection to the test socket. If the noise is your side of the master socket I'd expect to see a rise in sync or the same sync with an increase in SNR, if it's the other side of the master socket ie external I'm not sure what you can do as BTw may take little interest if the line is stable.

Not a criticism but both routers you've tried are getting a bit long in the tooth but there is sadly absolutely no guarantee a newer one would perform any better!

Gary · Feb 19, 2014, 21:30:51

at 11db though your line would run faster surely, Steve? The higher dB slows you down, hence a snr of 6dB is ideal and means you would run faster, unless you have a maximum sync on adsl and a lot of headroom. I would be inclined to reboot in the morning when adsl gibes you better speeds. You should really be able to get a maximum sync with that attenuation I would have thought almost.

Steve · Feb 19, 2014, 21:50:05

I assumed that at 11db the sync was the same so the connection was worse however I agree if the margin falls to 11 and the sync has a corresponding rise then that is obviously better. In the old days with adslmax if your margin was set to 15db you were stuck with it BT would not repeatedly reset your profile.

Gary · Feb 19, 2014, 22:10:28

I had a max adsl sync at I think 8128Mbos with an snr of nearly 12db and was on fast path. IDNet seem to be able to reset profiles quite often. Hopefully the test socket will help. Thanks for clarifying Steve.

duggy · Feb 19, 2014, 22:36:02

I am currently connected via a phone extension, so will try the test socket at the weekend.
I have also ordered a faceplate splitter and round RJ11 cable to see if they make any difference.
I live in a rural about 2 miles from the exchange, and have never had a sync above 6000kbps, but I am hoping that if I can get the SNR reduced them my speed may get to 6000-7000kbps.
I have heard that you can get alternative firmware for the 834PN that allows you to adjust the SNR at the router, have either any experience or views on this?

Steve and Gary your time and assistance is greatly appreciated, I will report back after trying the test socket.

Duggy

Gary · Feb 19, 2014, 22:51:47

Quote from: duggy on Feb 19, 2014, 22:36:02
I am currently connected via a phone extension, so will try the test socket at the weekend.
I have also ordered a faceplate splitter and round RJ11 cable to see if they make any difference.
I live in a rural about 2 miles from the exchange, and have never had a sync above 6000kbps, but I am hoping that if I can get the SNR reduced them my speed may get to 6000-7000kbps.
I have heard that you can get alternative firmware for the 834PN that allows you to adjust the SNR at the router, have either any experience or views on this?

Steve and Gary your time and assistance is greatly appreciated, I will report back after trying the test socket.

Duggy

Extension cord is never good for a router or for the line, it will act like an aerial and pick up all kinds of noise adn could be well adding to if not the problem maybe. The router ideally should be at the master socket. I had the 834PN. tbh it an old router now, you could try other firmware but I would suggest a Billion 7800N for your line, you can pick them up second hand, great routers and Steve had one and sang its praises. It is broadcom chipset based so good for longer noisier lines and it comes with the tools to adjust the snr etc from within the router as is. At this time I would try and see what can be done without 'fiddling' so everything is stable. Sometimes tweaking can cause more issue. Let us know how you get on.

Lance · Feb 19, 2014, 23:05:57

Sorry if I've missed it above, but have you disconnected the bell/ring wire in the telephone sockets?

Gary · Feb 19, 2014, 23:45:31

Quote from: Lance on Feb 19, 2014, 23:05:57
Sorry if I've missed it above, but have you disconnected the bell/ring wire in the telephone sockets?

Completely forgot that one, Lance

nowster · Feb 19, 2014, 23:57:46

A BT-supplied I-Plate will do the ring wire disconnection too. (That's all it does.)

duggy · Feb 20, 2014, 18:46:11

Hi Lance
The ring wire was disconnected at the master socket but was connected to the extension socket.
I have now disconnected it from the extension socket, but the SNR, attenuation ans sync speed are unchanged.

Gary · Feb 20, 2014, 19:40:17

Quote from: duggy on Feb 20, 2014, 18:46:11
Hi Lance
The ring wire was disconnected at the master socket but was connected to the extension socket.
I have now disconnected it from the extension socket, but the SNR, attenuation ans sync speed are unchanged.

extensions are not a good way to run a connection unless its wired in with either Cat 5E or cat 6 or BT cable. Flat wire is a no no.

duggy · Feb 20, 2014, 20:23:41

Hi Gary
I am going to try the test socket at the weekend to see if that makes any difference.
I do have 5m of Cat 5E that I can use, but would prefer if possible not to have the router in the living room, so wondered if this is what you mean by BT cable http://www.amazon.co.uk/dp/B004RONEXA/ref=pe_385721_37986871_TE_item. If not can you give me more information on BT cable please.

Duggy

Gary · Feb 20, 2014, 23:55:37

Quote from: duggy on Feb 20, 2014, 20:23:41
Hi Gary
I am going to try the test socket at the weekend to see if that makes any difference.
I do have 5m of Cat 5E that I can use, but would prefer if possible not to have the router in the living room, so wondered if this is what you mean by BT cable http://www.amazon.co.uk/dp/B004RONEXA/ref=pe_385721_37986871_TE_item. If not can you give me more information on BT cable please.

Duggy

You want something like this really http://www.run-it-direct.co.uk/adslcw1308patchlead2m.html CW1308 is the cable BT use to run though your house its easily tacked to the skirting board too.

duggy · Feb 22, 2014, 22:58:59

Today I have tried connecting to the test socket, but unfortunately the sync, attenuation and snr were just the same (sync ~5000, atten 38 and snr 15).
So I decided to install a different firmware on the router, that allows some adjustment of the snr. I have set the snr to the minimum possible, which is 9.5dB and this has resulted in a sync speed of 6848Kbps

Hopefully the ip profile will now increase to match the new sync speed.
I will see how this goes for now but I am definitely considering getting the Billion router suggested by Gary.