Should I use test socket for DLM?

[Isitme]

what does DLM actually set once it's finished? The noise margin target (with the minimum being 7dB)..?

DLM sets the speed, not the noise margin, at the highest it considers stable. This can result in a noise margin from close to 7 db upwards. If the noise margin it leaves is too high, it is often possible to get the speed increased manually.

[RUNITDIRECT]

With ADSL you are much better off using the router in your Master Socket. Any extension will reduce your connection speed. The exceptions to this are some properly made leads to replace the ADSL lead.

If the extension is good quality CW1308 cable or CAT5 as in the BT Extension kit then there will be no difference from the master socket. Use a filtered faceplate to filter all other wiring and run a dedicated ADSL extension if the master socket is not where you want the router to be.

[rhombus]

So, I guess I can conclude my internal wiring isn't a good job and probably not CW1308-spec cable because I get a download drop of 1dB attenuation and rise of 2dB noise margin compared to the test socket. I always thought this was unavoidable, I never realised it shouldn't be the case with decent wiring.

As I don't like to put up with bad jobs (and for peace of mind/perfection), I am sticking with the test socket during DLM line training - when it's over, I will then filter out my internal wiring with a faceplate, and rethink where/how to connect the router.

But that's the least of my worries now to be honest. MySky says line testing began on 10th September, the router log showed a re-up at 2.30am and said "xDSL G.994 training". I thought this should mean a jump straight away to approx 16Mbps, but here are my current line stats on 11th Sep:

ADSL Link Downstream Upstream
Connection Speed 6140 kbps 796 kbps
Line Attenuation 20.5 dB 15.5 dB
Noise Margin 17.4 dB 15.0 dB

I'm sure line speed can be fixed (Do Sky have the ability to manually reset the line training to start afresh again?)

Maybe more worrying - websites are sometimes slow to load, sometimes hanging for many seconds with the browser saying "Waiting for [the site]". I do a lot of live video streaming and calling, and am getting a lot of intermittent drop outs, which shouldn't be the case. I'm not sure why this is happening Download speeds are fine,and pingtest.net returns zero packet loss, 42ms ping and 2ms jitter. I always got 16Mbps with my old ISP, 16ms ping test on the same server, and flawless performance, without a glitch ever on live video streaming.

(For background: since activation on the 8th Sep I have only been using the test socket. On the 8th and the 9th I did disconnect and swap routers a couple of times to test username/password and compare line stats, but that was before line training began. I am testing everything with hard-wire, and have tried different computers etc)

Won't rush into anything , but seriously thinking I might end up cancelling and just going back with my old ISP... please any help or advice what to do, if anything, appreciated!

[Scubbie]

As is frequently mentioned, you can call Sky to get your line reconfigured once the initial DLM process has completed.

Personally I wouldn't want someone to reinstate DLM unless you are sure that it will raise the figures.

If, in your case, DLM reduces your line to such a low figure after a manual change, then consider getting someone to look at your line quality as it is an indication that something is seriously wrong.

If DLM has already completed (check you WAN uptime & the My Sky page), then a call is in order already.

Do ask about any CRC errors on your line (i.e. is it significantly high) when it is raised. If they are high, then is is a bad sign that the line has a problem.

[Isitme]

Usually the first jump is to around 9Mb, but you should not worry. You have gained 2 Mb at the expense of less than 1 db, which augers well for your final speed. For some reason DLM seems to have a bit of difficulty with very good lines, which yours appears to be. I have seen quite a few where the line is obviously good, but the speed rises slowly. I know it can't be true but it is almost as if DLM can't believe the line is so good and is conservative about how much it puts it up. Unless you are getting very bad noise spikes during the night hours, I can't see noise being a problem and causing errors.

[rhombus]

Thanks for the replies.

In the meantime, I called Sky (after finding a freephone number, since my talk package hasnt been activated yet!).

The nice lady said she would re-profile my line. 2 minutes later, I get this :

ADSL Link Downstream Upstream
Connection Speed 16122 kbps 796 kbps
Line Attenuation 20.5 dB 14.4 dB
Noise Margin 7.3 dB 14.0 dB

She said line training would continue - hopefully figures will improve even further.

But I'm suspicious about the 16Mbps, I did mention "I thought I'd see at least 16 Mbps" before she did her stuff. I guess it's either the starting point for line training, or maybe she has set it like that for good? (I'm still going to educate myself about line profiles, training and all this!) I hope it isnt set for good, cos I'm thinking I probably underestimated with 16Mbps given my line attenuation and that now im without internal wiring....

Will see how it goes and update. The other issues are much more important to me than download speed, lets see.

[Isitme]

If you had let DLM do its stuff you would probably have got 18Mb+, I doubt if you will see much more than you have after a manual configure.

[timc]

Hi rhombus

I've just PM'd you a question.

Tim

[rhombus]

If you had let DLM do its stuff you would probably have got 18Mb+, I doubt if you will see much more than you have after a manual configure.

I can accept that (download speed isn't my priority right now, but I would still like to learn). How would DLM get a higher speed? Maybe you could first please explain what parameters are set by a manual configure by Sky? I understand ADSL2+ is fully rate adaptive, and the DSLAM sets a target SNR noise margin for syncing with the router. What else is set in a profile?

Thanks

[User05]

I can accept that (download speed isn't my priority right now, but I would still like to learn). How would DLM get a higher speed

If the person who profiled it doesn't understand how INP affects the speed, and many don't.