Supermax sync speeds

[Mark_S]

Hi Guys,

Just got activated today for Supermax. 

Sync speeds seem unusual, 832 kbps UPSTREAM, yet only 768 kbps DOWNSTREAM. 
The order page promised 2.5 Mbps  but now states ADSL Max services should provide 500 kbps or more. 

Just wondered if any of you have had similar trouble and if so what you did to put it right?

Cheers,
Mark

[Rik]

Hi Mark, welcome to the forum.

Can you post your line stats, d/s attenuation, noise margin and sync speed please, and also do a BT speed test:

http://test.speedtester.bt.com:50301/

Some patience may be required there. Generally, we have found people are more likely to succeed with IE rather than Firefox, and mornings are usually easier than evenings.

With the stats, we can judge whether you  have a profile problem which will cure itself, or whether you have an issue with your line or internal wiring.

Unfortunately, I'm just off for the evening, but others will be along shortly, and we'll be here throughout the evening.

It would be useful to know what router or modem you are using, and which OS.

You might also want to read our wiring guide here:

http://www.idnetters.co.uk/forums/index.php/topic,1904.msg31528.html#msg31528

[Mark_S]

Thanks for the quick response Rik.

The problem seems to be with the downstream link. I can send data up the line at the absolute full rate, yet can only recieve at about 80% of that speed. Based on the line length and quality here, I was expecting about 1.5 - 2.5 Mbps downstream, and nothing like 832 kbps upstream.

Router:  SMC ADSL Barricade N Pro - SMC7904WBRA-N

Line Status:  SHOWTIME
Link Type:  Interleave Path
Upstream:  832 kbps <------------------------(Maximum sync.)
Downstream:  768 kbps <---------------------(Extremely low sync. considering above)
Noise Margin:  7 dB up,  9 dB down
Attenuation:  29 dB up, 63 dB down

HRC Error:  0 near end,  0 far end
CRC Error:  1 near end,  0 far end
Received Cells:  37401612
Transmitted Cells:  6070250

ADSL:  CONNECTED
WAN IP:  91.135.xx.xx
Subnet Mask:  255.255.255.255
Gateway:  212.69.63.51
Primary DNS:  212.69.36.3
Secondary DNS:  212.69.40.3

IP Address:  192.168.xx.xx
Subnet Mask:  255.255.255.0
DHCP Server:  Enabled
Firewall:  Enabled
UPnP:  Enabled
Wireless:  Enabled   

Numbers of DHCP Clients:  2
Runtime Code Version: v0.90 (Aug 14 2007 19:00:48)
Boot Code Version:  V0.06
ADSL Modem Code Version:  2.1.2.15.0.1
LAN MAC Address: 00-13-F7-96-05-0E
Wireless MAC Address: 00-13-F7-96-05-0F
WAN MAC Address: 00-13-F7-96-05-10
Hardware Version:  01
Serial Num:   J751358627

[Mark_S]

Oooops, forgot to post the speedtest results.

Test1 comprises of Best Effort Test:  -provides background information.
    IP profile for your line is - 500 kbps
    DSL connection rate: 832 kbps(UP-STREAM)  768 kbps(DOWN-STREAM)
    Actual IP throughput achieved during the test was - 457 kbps

The annoying thing is, it was doing better when first connected, as the IP profile was 2000 kbps.

[plugwash]

Does your system have a NTE5 style master socket and if so have you tried the router plugged into the test socket with all extensions disconnected?

Have you had broadband on this line before and if so what speeds did you get?

[Mark_S]

Hi plugwash,

Yes, I have an NTE5 (new Openreach branded) and all the testing has been done from the test port. The line has only been in for a couple of weeks and has never had broadband provisioned.

The IP profile has dropped from 2000 kbps to 500 kbps since this morning - and the throughput has dropped as well.

[Simon]

Speaking as a non-techie, it sounds like the line is still training, Mark, and I think you have to allow at least 5 days, possibly 10, for things to stabilise.

That said, someone more on the ball than me will analyse your stats, and may have some ideas.  In the meantime, you might like to have a look at our FAQs, which may provide some more info for you. 

[Sebby]

Hi Mark, and

Unfortunately, I'd say it's very unlikely things are going to improve in the next 10 days. The training period is just a time used by BT to establish a Maximum Stable Rate (MSR) and from that a Fault Threshold Rate (FTR). ADSL max is rate-adaptive, so unless there's something that is causing this problem at this point in time (such as a noise source) then things are not going to change.

Now, onto the problem. You have a very high attenuation (assuming it's being reported correctly), and so I wouldn't expect a great sync. Also, it's important to remember that the broadband availability checker estimates line capability, and the actual result can be higher or lower.

That said, things are looking a little low for your line; I'd certainly expect you to achieve better than that. You could give IDNet a call, but I suspect they are going to be held back by the 10 day training period. If this is the case, speak to them after this period and see if they think it's worth escalating to BT. Personally, I feel that if you're getting that sync in the test socket, something isn't quite right.

I hope this helps. Let us know if you need any further help.

[plugwash]

very high attenuation sounds like a bad connection somewhere probablly in british telecoms wiring though I might be tempted to try a different router and cables in case they are the problem.

What is the line like for voice? If voice is at all imperfect I would report a fault there as you may get a much faster response from BT that way.

[Rik]

I'm puzzled that the d/s sync is lower than the u/s, however, it does use lower frequencies which are less prone to attenuation. Most routers can't report attenuation greater than 63db, so the figure may actually be higher. I have a feeling that you are on a very long line, Mark and may struggle for much of an improvement. If you were on a fixed-rate product, Mark, BT would only give you 512k.

If the test socket results are better, look at improving your internal wiring, but I have a feeling that you're not going to get a lot more speed than you already have.

[Sebby]

very high attenuation sounds like a bad connection somewhere probablly in british telecoms wiring though I might be tempted to try a different router and cables in case they are the problem.

Not necessarily. In this case, it could indicate a fault, but usually high attenuation is just a result of being such a distance from the exchange.

[Mark_S]

Thanks again for all your input.

Echoing Rik's observation, I can't work out why the U/S sync is better than the D/S sync. After all it use far less of the frequencies for upstream. The upstream speed is also rate adaptive, so it would seem unlikely that I should ever achieve a better U/S than D/S sync.

I get the feeling that the problem lies either with a faulty modem in my router (will test another router when I get the opportunity), or with a faulty card in the DSLAM. Getting BT to investigate the latter, however, will undoubtably be an uphill battle. 

The line is, as many of you have worked out, quite some distance from the exchange, maybe 2.5 - 3 km as the crow flies and 5.07km driving distance according to multimap. Should I expect better performance from the line?

Mark

[Rik]

Your attenuation suggests an actual line length of more than 6km, Mark. That's probably about right for a 5k driving distance, as cables tend to follow slightly circuitous paths.

It's certainly worth trying a different router, and making sure your internal wiring is not adding to the noise, but I suspect that the killer is the line length. Had you not been on SuperMax, your figures would have looked quite normal.

[plugwash]

you might also want to consider a package downgrade. IIRC to get the higher upstream speed bt wholesale adsl max premium allocates more frequency bandwidth to upstream and less to downstream than BT wholesale adsl max.

[Rik]

That's certainly what I've been told, PW, I've also been contradicted when repeating it.

[Mark_S]

Hi Guys,

Well I`ve just connected a different router, a DLink something or other, and my sync has jumped to 1728kbps D/S and 768kbps U/S. The IP profile has even picked up to 1.5Mbps and the BTw linechecker states that the line should be capable of 2Mbps or more. Result. 

Looks as though the SMC will be going back to PC World for a refund. Anyone have any recommmendations for modems/routers that work well on marginal or long length lines? I'm looking to squeeze that last ounce of speed out of this woeful bellwire that BT have had in the ground for the last 100 yrs. 

Re the package downgrade, should I consider that, as I have also heard the the Supermax style services use more of the DMT 'channels' for U/S speed (stands to reason) at the expense of D/S speed (also seems a reasonable assumption). However, Dunfermline is a busy exchange and I noticed none of the other packages include prioritised traffic shaping at the exchange. Does anyone know if this makes much of a difference?

Mark

[Rik]

Hi Mark

For long lines, the 2-Wire 2700 HGV has got a big fan club on here. I gained 1000k by using one, taking me from a 2000k profile to a 3000k one. The downside is that they are primarily available only on eBay.

I've not used SuperMax, but most people don't see to notice a huge difference in priority, they tend to go for it for the upload speed. As you say, this can detract from the d/l speed, so you might want to think about dropping down to an ordinary Max package.

[Mytheroo]

am on supermax but my exchange only serves around 700 households so I havent really noticed it being much better than Nildram (pings and in-game wise)

On a side note, mom's is about 5-6km from exchange with 61db attenuation. Had syncs of up to 4mbit with SNR of 5db but was unstable. Is currently set to 12db SNR and 2mbit with rock solid sync, however next door neighbour on same ISP (talktalk lol) can only get 1.1 sync, he nearly choked on his tea when I said I had it running at 4mbit hehe.

supermax uses more of the lowend DMT channels for upload, but I'm not sure if they use the ones below channel 31 (normally unused to give cheaper voice filters more chance of attenuating the DSL signal i think) or some of the channels normally used for download