SNR question

Hello

I'm having trouble logging in so posting anonymously.

I'm with Virgin Media (National) connected to the Dalkeith exchange, so using C&W LLU, as advised here before. Our router was off for a couple of weeks in July and when we came back, the SNR rose to 15, with 5 loop attn, giving us about 15Mbps synch speed. After fiddling with routers etc., I've now settled down with a Draytek 2820n, which has been synch without a dropout for 2 weeks solid (wow - never been connected without dropout for so long before). Could you advise pls whether and if so, when, SNR should drop down to 9 and then to 6? I've heard somewhere it'll have been 3 weeks before it happens - is this true?

Thanks for any help.

Nope.

Your SNR won't drop below 9db on that LLU service as that is the default/general minimum on the equipment.

Matt

Does it drop automatically at all on C & W LLU?
(I'm assuming the OP is meaning his line rental is with VM National).

Nope.

Some exchanges will see a lower profile if the port was already on it but the general standard is 9db (with 8ms interleaving).

They don't use or have a DLM system at all.

Matt

thanks.

really? we were on 6db beforehand and then it went up to 9db and now it stands at 15db. at some point, we ended up having 3db but for a very short period of time. i'm really confused about all this and why we used to get 21mbps synch speed (ca. 17 mbps actual download) and now it's 15 (13 actual download).

The target would have been much higher, but the SNR can change over time and it sounds like you may have another issue causing the massively fluctuating SNR.

Matt

yes, our line rental is with virgin national, but, as some of you advised on here, we're using c&w llu thingy.

Matt,

I didn't want to open a ticket on my uno Pro 24 75GB CPW SMPF account because it was not a serious issue but after a power cut the other day my downstream sync increased from ~13Mbps up to nearly 15Mbps (with a corresponding increase in downstream throughput) yet downstream SNRM remained at 6dB at sync time as did my downstream attenuation of 37dB, not certain of interleaving depth though.

Later on the same day there was another power cut (further repairs to a blown mains cable affecting all the properties in the street) and when power was restored the downstream sync returned to normal at ~13Mbps, interleaved, SNRM at 6dB and attenuation at 37dB.

I removed the router from the mains during the power cuts in order that any possible surges or a very short return of power (which sometimes happens after a power cut before steady power is restored around here) might cause problems.

Just out of interest have you any ideas why there should have been such an increase in downstream speeds after the first power cut - distance from the blown mains cable to the cabinet is about 10 yards and much closer to underground telephone cable if that's relevant?

Which ISP do you get the C & W from?

Any chance of posting the link to a www.speedtest.net result please?

Might be best starting a new thread for your issue as your problem will only confuse people (me!) reading this one!