Slower Than Expected - The SVBN Effect?

Hey all,

Brand new to Sky, previously on cable, also took UK Online delivered over Easynet's Lucent kit way back when.

This line appears to be underperforming quite considerably.

ADSL Link Downstream Upstream
Connection Speed 16381 kbps 1101 kbps
Line Attenuation 17.0 dB 11.4 dB
Noise Margin 5.9 dB 8.9 dB

I've had a 14Mb sync on a 34dB line and 23Mb along with 2.3Mb up on a 21dB line, both with Be, and I'm a bit confused as to why the shortest line I've ever had barely beats a line twice as long and doesn't touch one 300 metres longer.

I'm also quite looking forward to seeing what happens in the winter when the RF interference levels increase. Either the line sucks or the SVBN in combination with the Sky modem sucks, any opinions and experience welcome.

Plugging into the test socket does nothing incidentally, there are no extensions anyway.

It's a jittery crapsack too.

http://www.pingtest.net/result/68200234.png

Just had my latency and jitter outperformed by someone nearly 200 miles north of me on the end of a 71dB attenuation line.

Did your line go through DLM line testing or have you had someone manually apply a line profile?

In reply to a post by Oliver341:

Did your line go through DLM line testing or have you had someone manually apply a line profile?

Both, was briefly taken off DLM then put back onto it. There's no fixed profile on there at this time, the line is rate adapting to that level with a 6dB target margin downstream and some random high figure upstream.

The line sucks and you're probably on full interleave. The best you can do is ask for a Gaming profile.

In reply to a post by BatBoy:

The line sucks and you're probably on full interleave. The best you can do is ask for a Gaming profile.

Also perhaps break the terms and swap a different router with different line chips. Just a thought.

Ignore batboy.

the line is not bad.

Its not far off being the same as mine.

Ive got a 11db attenuation and i get 18mb sync speed.

But ive tweaked my line down to 2db snr to get the full 24mb sync speed.

I do wonder what attenuation/snr combo will give the full sync speed.

I would of thought yours and my line would get the full 24mb but they dont, witch i find odd

Perhaps plugging in a router with decent ADSL stats (e.g. Technicolor or Netgear+telnet) will give more clues, e.g. power output. Don't worry about extracting user/pass and such, you don't need to auth to pull the stats.

Ignore Seansmit17.

ADSL Link Downstream Upstream
Connection Speed 16381 kbps 1101 kbps
Line Attenuation 17.0 dB 11.4 dB
Noise Margin 5.9 dB 8.9 dB

Ok. Looking at those stats there's a good attenuation. Based on that you can probably get a few more Mbps.

The noise margin, ignore it. Basically whatever speed DLM sets it reduces the power... So even though the noise margin is bang on target it doesn't mean you can't sync higher and still maintain the same noise margin.

If DLM had set your line to 14000 kbps that SNR would still be a similar value no doubt.
Here sky is different to most other ISPs who would maintain a higher noise margin.
This saves Sky money as it means their equipments not blasting unnecessary power down a line. It's part of their eco initiative

Sooooo looking at the stats you've almost certainly gone via DLM. That's because the sky profiles wouldn't give you that upload at 16Mbps

Rightio. Ring Sky up and firstly ask them to put you on an 18Mbps profile. NOT A 16 Mbps profile.
18Mbps is the first profile that maintains full upload.
See if the speed increases. If it syncs at the full 18Mbps ask for a complete uncap to 20 Mbps.

SKY nowadays can only set the following profiles manually
4Mbps, 10Mbps, 16Mbps, 18Mbps and 20Mbps.
4 - 16 Mbps has an upload around 765 and 18 & 20 have full upload.

DLM can set any sync speed. Hence why it's often the best route. Also DLM will keep a high upload even on low profiles.

So yep ask for the 18Mbps profile and then the 20 if you achieve full 18. Don't worry about interleaving for now.

To check you are in the master socket? You have disconnected the ring main on any extension sockets? You have tried in the test socket and got similar stats with similar noise margin levels?

Should add that Sky don't do a 2Mbps upload. So don't expect that to get any better. Uploads already maxxed out.

Edited by ukhardy07 (Sat 18-Aug-12 23:48:03)