It's because if the SNR is high, it means the line could be running faster.
Think of noise margin (or SNR) as being headroom to ride out interference or reduction in signal.
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Think of noise margin (or SNR) as being headroom to ride out interference or reduction in signal.
Guineafowl
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About an hour before the engineer turned up, another Openreach van came in - apparently they're scoping the area for fibre to the property. Won't be for a while, though, as it's just in the planning stage.
What we have is this:
I wasn't in the master socket. The phone line comes in somewhere unknown, there's a buried junction box we can't find, which tees to the master upstairs and the downstairs slave one, which isn't ideal. The master should be the first connection.
Apparently the connection was ok, but there was an unusual number of errors coming through the downstairs one. Less upstairs, presumably due to the filter (?) cap.
He's fitted a proper master socket downstairs as a trial, and disabled the upstairs one. (Bad place for the router, at the far end of the house).
Its a 21CN cabinet using ADSL1 (8 meg), which could be switched to ADSL2(24 meg) quite easily, if that's relevant.
Also gave me a big handful of gel crimps, which was nice...
What we have is this:
I wasn't in the master socket. The phone line comes in somewhere unknown, there's a buried junction box we can't find, which tees to the master upstairs and the downstairs slave one, which isn't ideal. The master should be the first connection.
Apparently the connection was ok, but there was an unusual number of errors coming through the downstairs one. Less upstairs, presumably due to the filter (?) cap.
He's fitted a proper master socket downstairs as a trial, and disabled the upstairs one. (Bad place for the router, at the far end of the house).
Its a 21CN cabinet using ADSL1 (8 meg), which could be switched to ADSL2(24 meg) quite easily, if that's relevant.
Also gave me a big handful of gel crimps, which was nice...
Guineafowl
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Always ‘nice’ to find a Fast Show fan
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Nope - the connection went down last night again.
I'll call the engineer back, but I'm not sure what he can do, short of starting with a new line in. He was really good - spent about 2.5 hours here investigating and trying things.
I'll call the engineer back, but I'm not sure what he can do, short of starting with a new line in. He was really good - spent about 2.5 hours here investigating and trying things.
Guineafowl
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That was the one they sent two weeks ago! Maybe trying to get rid of old stock.
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Second Openreach engineer has just been.
Agreed with @qwakers that the router they sent me was an old one.
Very few errors on the line test, but he's upped me to a 9 dB margin to give more headroom for interference, if I've understood it right.
Problem is, it always fails in the evenings, not when the engineer is here. Possibly crosstalk when everyone gets home and starts using the internet.
Also going to get a newer router sent out.
Agreed with @qwakers that the router they sent me was an old one.
Very few errors on the line test, but he's upped me to a 9 dB margin to give more headroom for interference, if I've understood it right.
Problem is, it always fails in the evenings, not when the engineer is here. Possibly crosstalk when everyone gets home and starts using the internet.
Also going to get a newer router sent out.
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That basically means it will connect a bit slower. SNR reduces overnight so setting a higher target noise margin should mean it's less likely to drop far enough to cause a problem.
Does the timing correspond with anything happening in the Home or neighbourhood? Street lights coming on, central heating etc?
Have a listen on a short wave radio to see if there are any strong signals anywhere along the line to the cabinet. If there is such a signal, it may not be near you. See if it's there when the line is "good".
If you don't have such a radio, consider one of these rtl-sdr dongles and an on-the-go cable for your phone:
Or it could just be a contention issue. Someone else that effectively shares the connection comes home from work and does a big data dump or backup. They may not even know they're doing it. It could be their smartphone syncing with cloud storage.
If you don't have such a radio, consider one of these rtl-sdr dongles and an on-the-go cable for your phone:
SDR Touch brings RTL-SDR to Android
SDR Touch is an Android app which allows the rtl-sdr dongle to be used on an Android device. A USB OTG (on-the-go) cable is required to connect the android device to the tv dongle. The blurb on the app authors website reads (SDR Touch) Turns your mobile phone or tablet into an affordable and...
www.rtl-sdr.com
Or it could just be a contention issue. Someone else that effectively shares the connection comes home from work and does a big data dump or backup. They may not even know they're doing it. It could be their smartphone syncing with cloud storage.
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Guineafowl
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Yes, speed is down to 3.2 Mb now. He also added interleaving.
Out in the sticks, so no street lights. Bit late for central heating. But yes, I'll bear that sort of thing in mind.
All I've got is a couple of valve radios that do SW. I might get a little modern battery one. Some talk online of listening at 612 kHz (490m).
On the engineer's advice, I've requested an upgrade to ADSL2, since the cabinet is 21CN and able to support that. Should help with the fault.
Had an interesting chat with BT about the 'morals' of charging me extra to meet the minimum 10Mb universal service obligation, help cure the fault and replace the aged router. Got discount.
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Could be, but not much I can do about that. It seems unlikely, as once the connection goes down, say 8pm onwards, it doesn't come back again, even at 1 or 2 am.
Interleaving adds a bit of delay but only reduces speed by a tiny amount. It's normally th first configuration change if a line starts showing errors. Essentially allows more errors to be corrected.
ADSL2 would be best for your line length/attenuation. Some say to switch off ADSL2+ on the router if you're on a long line, as the high frequencies aren't likely to work.
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They've apparently switched me to ADSL2, marketed as BT Halo 3, but nothing seems to have changed. Data rates are 448/4.06, modulation is G_992_1_ANNEX_A, which apparently is ADSL.
Connection still dropping out, but last night was 0.1 Mb rather than 0.
Am I waiting for a new hub? Not clear from the confirmation emails.
Connection still dropping out, but last night was 0.1 Mb rather than 0.
Am I waiting for a new hub? Not clear from the confirmation emails.
Are you, or any close neighbours, using ethernet over powerline adapters of one shape or another, by any chance? They generate broadband interference when they're running, particularly if passing data. It could be that they're ticking over on standby, during the day, until the TV and/or other data-requiring devices start getting used. This type of interference could be getting into the ADSL cabling. Modern "smart" TVs can continue to be active, and possibly use the internet, for some time after they've been "turned off" using the remote control.
ADSL2 is G.992.3, ADSL2+ is .5. Annex A means unit runs over a normal telephone line (Annex B runs over ISDN).
You're not going to get anywhere near the maximum speeds for 2 or 2+ as the higher frequencies won't be usable at that distance. But it should give you a higher upload of up to 800k or so.
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Thanks. it looks like I need to get back onto them, as the new, more expensive ADSL2 service is meant to have started. Do they do the switch remotely, or does there need to be fiddling in the cabinet?
I am over in Queensland Australia so my situation will be different to yours however what I have found is the the routers that the providers supply are cheap and nasty, it will cost you a bit but if you can afford it, get a decent router and by that I mean not the cheapest router available, however having said that if you are on copper at the moment and you decide to go fiber to the street you may need to change routers again, when you mentioned fiber to the street, is that fiber to the premises or fiber to the node? The latter one is copper from the node in the street (FTTN) to your house and the former is fiber all the way to the exchange (FTTP).
FTTP is the way to go provided it is affordable and or available, when I moved into my newly built house 18 months ago, only FTTN (50/10) was available which was a real pain as I had to dig up and use a very old router/modem (Netcomm NF4V) I still had, I had been on FTTP for about 7 years before so had the correct router for FTTP (Asus RT-AC87U) then two months later they upgraded the street to FTTP, so back to my last router and connected to 100mbps, then 250mbps (different supplier) and now on 1gbit (again changed to a different supplier). The 250mbps and above is pretty much superfluous but as it was available and just slightly more than the 100mbps, so I figured why not. I upgraded the ASUS RT-AC87U as it was a bit old as I bought it used to a new ASUS RT-AX89X. The NBN is now talking about upgrading to 2gbps mid next year but I won't bother, if it is at the same price I will, but I doubt that it will stay at the same price.
FTTP is the way to go provided it is affordable and or available, when I moved into my newly built house 18 months ago, only FTTN (50/10) was available which was a real pain as I had to dig up and use a very old router/modem (Netcomm NF4V) I still had, I had been on FTTP for about 7 years before so had the correct router for FTTP (Asus RT-AC87U) then two months later they upgraded the street to FTTP, so back to my last router and connected to 100mbps, then 250mbps (different supplier) and now on 1gbit (again changed to a different supplier). The 250mbps and above is pretty much superfluous but as it was available and just slightly more than the 100mbps, so I figured why not. I upgraded the ASUS RT-AC87U as it was a bit old as I bought it used to a new ASUS RT-AX89X. The NBN is now talking about upgrading to 2gbps mid next year but I won't bother, if it is at the same price I will, but I doubt that it will stay at the same price.
