After the thunder & lightning today :(

[joe pineapples]

We had a very close lightning hit, probably in the street, and noticed afterwards one of my Comtrend 902 powerline plugs has died...the one which was connected to the router. Net works ok with direct wire connection but my router stats have dropped quite a lot. Its now syncing at 2860 down, whereas was around 8670 (SNR about the same). Tried resetting the router but still the same, and the phone line sounds as clear as before.

Wondering if I should get hold of another filter to try, but if the phone sounds clear, isn't it doing its job?. Also is it worth phoning Sky support on a Sunday or leave it till Monday.

*EDIT* Just noticed my line attenuation is reading 77 . Normally 39

[DarkCerberus]

Getting another filter may not work if the thunder & lightning hit the exchange box - please get in touch with your ISP in this case BSkyB they'll then get either an engineer out or a BT engineer to check the exchange since they own nearly all of the exchange boxes...

[seawright]

If you have a test socket on your master socket it would be best to check with your router plugged directly into the test socket. It won't increase your speed but if you get a significant increase in noise margin the lightening strike may have caused a fault in your internal wiring.

When you call tech. support they will probably ask you to do this anyway so it would be better to be armed with the requisite information before making the call.

[joe pineapples]

Thanks guys. The router is always plugged directly into the master socket (older none test socket version). I have since tried another filter which made no difference, so will ring Sky in the morning. (just phoned but the better informed people are not there today).

I kept mentioning the ATT of 76, but tbh it just didn't seem to be sinking in .

[tenar]

its just they are not taught what a higher attenuation means , but they should be be able to see that your line speed has dropped and escalate that if all line tests passed and physical checks done.

[joe pineapples]

Tried everything they asked and they did line tests etc. Finally they got me to try my old router (which I didn't realize I still had - doh!). That sorted it, so new router on the way (faulty one still under one year old). She seemed quite amazed that if it was the electrical storm that caused it, that it wasn't knocked out completely.

The old Sagem actually sync'd a bit higher than the SR101, but I got the newer one for its ability to hang onto a lower SNR (which my line is prone to doing these days), so I think I''ll still use the new one when it arrives.

[joe pineapples]

New router arrived today. Its the Sky Hub v2.0 VDSL, if that's any good. My speed is lower than originally was with the temporary Sagem I was using, but that had itself resync'd at the same speed this morning anyway. Pings are down from what I've always had....35 down to 20 (pinging bbc.co.uk). SNR is sitting at 8.1db at the minute so hoping there might be a bit of margin to get the speed a bit higher, if line training has kicked in. On that subject, is there a way of telling from the router stats if it is in progress, rather than the unreliable 'mysky' method, or phoning them up.

[gymno]

There's no way to tell if DLM is training having switched routers & reset everything back to zero, but you can do from now on.

DLM usually resyncs the line between 2 & 3am although it can occasionally happen at any time between midnight & 6am.
These resyncs cause the WAN uptime in the router stats to reset to zero, so that's a good indicator.

Personally, with a downstream noise margin of 8.1db showing a potential for more speed, i'd be on the phone asking for DLM training to be run.

[Saturday]

is there a way of telling from the router stats if it is in progress

No. A noise margin of higher than ~6db immediately following a reboot tells you that either your line is good enough to max out your available sync so there's margin to spare, or that a higher noise profile has been set either manually or by DLM. The latter doesn't tell you whether this is the "final" adjustment or whether it is actively profiling your connection*.

If your router resyncs in the early hours (typically around 3am) then that may mean that DLM is actively profiling. If it resyncs two nights running then that is probably DLM.


* Sky's DLM runs continuously, monitoring the connection for issues. If it detects a problem then it goes into what might be called "active mode". If the DLM adjustments return the connection to a pre-defined set of parameters then DLM goes back into background mode. If it then subsequently detects an improvement or further deterioration in the connection characteristics then it again goes active. Sky can actively trigger it too.

DLM essentially seeks to achieve a stable connection with the highest sync speed attainable. With a great line DLM will allow a 3db noise margin with no additional error correction i.e. fastpath. Otherwise it will adjust noise margin and add interleaving (and utilise G.INP** where available apparently) to get the best compromise it can between sync speed and low error levels/stability.


** As far as I can tell, and info is scarce at the moment, G.INP seems to effectively make dynamic changes to interleaving without needing a resync. That's not as good as Seamless Rate Adaptation (SRA) would be but I guess it would be useful on a line which has say intermittent low level REIN issues. Varying latency might annoy gamers but presumably not as much as variable packet loss would.

[joe pineapples]

Thanks. Sounds like I'll be best to leave it for a few nights at least and see if anything telling, changes in the stats. If nothing does, I'll ring them and see if they'll trigger it manually. I have tended to find them reluctant to do anything when they think I'm getting a 'decent' speed. I guess they just want the quiet life, and not entertain people wanting the 'best it can be' (like myself).

On a side note to that thunderstorm.......found out both the neighbours opposite and another around the corner, had their digital phones die. Makes you think to take precautions next time.