Quick LLU Sync Speed Question

Hi All,

I'm about to place an order to move over to Xilo on the C&W LLU package. At the moment I'm with Zen and currently get a sync speed of 9Mbps - 10Mbps (depending on the day and if there's a following wind!). My upstream is around 1Mbps.

Will I see similar speeds on C&W LLU?

Downstream Attentuation: 33dB
Downstream SNR: 6dB

Upstream Attenuation: 13dB
Upstream SNR: 5dB

If you're on ADSL2+ modulation, that attenuation should sync at around 14Mb. I don't know why you're not seeing that now, but it may be line noise as your SNR is 6dB.

Hi Batboy,

When I moved to ADSL2+ last year I checked various checkers and they said around 14Mbps. I raised a fault with Zen but they said there was no fault on the line. Even plugged into the test socket it never synced higher than 10Mbps.

Just want to make sure I would see a similar speed on C&W LLU (ADSL2+) or higher (e.g. closer to 14Mbps).

Without trying to burst your bubble, you may see less as C&W's minimum SNR profile is 9db, not the 6db you are currently seeing.

If you can tweak this, that may be a work around but they do not support anything lower.

Matt

Hi Matt,

Thanks for the reply. To be honest, BTs DLM really doesn't like me on 6dB despite those line figures. It kept chucking me on 9dB which gave me a 8Mbps / 9Mbps profile. I asked Zen to reset the profile and have been monitoring it to see how long it will stay at 6dB. So far it's managed about a week but there have been several disconnections (the line was always more stable on 9dB).

As long as the line is stable and I can get a usable service 24 x 7 for the right price then I'm not that worried. Hell, it's only a one month contract so I could always migrate away.

Now Matt - any chance of a discount on the "migrating in" fee.

Have a read through the whole of my Troubleshooting section, apart from the "Router acting oddly" page. There's a fair chance of something in there pointing to what is holding your connection speed down.

Hi Robert,

Thanks for that. I've done most of those checks (e.g. removed the bell wire / replaced the microfilters / no sky box to worry about). Cables are not looped and power cables are separate where possible. The only think I haven't done as yet is replace the cable from the master socket to the extension as it currently runs under a fitted wardrobe. However as I stated earlier I did test in the test socket and even then the router failed to sync at anything above 11Mbps.

We do have a small box just inside the property where the external BT wire comes in and is joined to an internal wire which goes into the NTE5. I've taken the cover off and the wires are joined with some gel connectors - I don't know if they would need replacing? TBH the line is quiet and works at the moment so I don't want the hassle of trying to find out from BT if it needs replacing and if it would increas my BB connection. The box is similar to a BT80A RF2 but there is no circuit board inside, just the cables connected via gel connectors.

Do any of your immediate neighbours get better speeds?

Half of my neighbours are over 70 and don't know what broadband is, the other half know what it is, but couldn't tell me what package their on or what speed they get / should be getting.

My Speeds were much slower (1.8). In my case the BT equipment apparently has "Too many connections (BT advanced fault team + 3 months). The switch away to the C&W LLU though Vivaciti cured this and gave me better speeds (now 3.4).

I think we could all learn a lot about our broadband by visiting a few neighbours and taking them through a few speed tests, noting and circulating the results.

In reply to a post by aquilla:

Now Matt - any chance of a discount on the "migrating in" fee.

Sorry - no offers on at the moment

Matt

Ever tried a different router? Or reset yours to factory defaults, (assuming you don't have a complicated setup in which case a configuration backup first is a good idea). The first might help, the second I doubt it, but you never know.

No worries Matt. I signed up last night and got a confirmation email this morning. Should be on by 26th May.

In reply to a post by RobertoS:

Ever tried a different router? Or reset yours to factory defaults, (assuming you don't have a complicated setup in which case a configuration backup first is a good idea). The first might help, the second I doubt it, but you never know.

Hi Robert,
That's the one thing I haven't changed as yet. I have a Cisco 877 which is connected to a Draytek 120 ADSL modem. The Draytek handles the line sync (as the Cisco has trouble with ADSL2+) and the Cisco does the authentication and routing.

I *think* I have a spare ZyXel 660HW tucked away somewhere. If it's ADSL2+ compatible I might give it a shot. Otherwise I'll see if I can pinch a Draytek 2820 from work for a week or so.

Well well well. I've just found the ZyXEL 660HW-61 (bought in about 2004!) and it still works. Flashed it to the latest version so it supports ADSL2+.

I have just plugged it into the test socket and here are line stats it's reporting:

noise margin downstream: 6 db
output power upstream: 12 db
attenuation downstream: 28 db

noise margin upstream: 5 db
output power downstream: 21 db
attenuation upstream: 15 db

According to me (and from checking the line stats on the Draytek), I have just *gained* 5dB on the downstream. That's one hell of a gain if it's correct. The line is currently sync'ed at 11774kbps down and 1110kbps up. Now I just need to move the ADSL modem to its proper home (off the upstairs extension) and see how it performs.

Remember a connection made in daylight times can be 1Mbps or more higher on ADSL2+ than one made when it is dark.

Hi Robert,

I'm aware that connections made at night can be lower due to higher levels of RF interference. However what I am surprised about is that when the Draytek was plugged into the test socket it reported an attenuation of 33dB (as seen at the top of this post). When I plugged the ZyXEL in last night it registered a lower attenuation and synced at a slightly higher speed.

Anyway I moved the ZyXel to its proper place last night, plugged it all in and got a downstream attenuation of 29dB (despite the Draytek registering 33dB with the same cabling setup). It's currently synced at 11784kbps / 1136kbps.

Oh well.

Different makes of router can report 3dB or so different downstream attenuation, there doesn't seem to be a standard way of calculating it, because of course the attenuation on each frequency/bin is individual, and the single figure is some sort of average.

Unfortunately it seems that this overall figure is reported to the DSLAM and used in the sync speed setting.

The stability of Drayteks appears to me to be very much linked to this. They connect slower, so of course are more stable.

Edited by RobertoS (Wed 18-May-11 23:25:26)

I've just been connected to Xilo.

Zen connection down at 13:56. Changed the login details and Xilo up at 14:03. Nice and swift. Currently synced at just under 11Mbps with a 9dB SNR (which is the standard for C&W).

Just downloaded the 100MB test file from Zen (sorry Xilo, it's the first one that I thought of). Download of 100MB took 93 seconds at a rate of 1.07MB/sec.

It's a good start, long may it continue.

(Yes I know I need to update the signature before anyone mentions it).

Do always have a play with our speedtester if you need to..

http://speedtest.uno.net.uk/

Matt