cancel
Showing results for 
Search instead for 
Did you mean: 

Speed restriction?

Neo
Grafter
Posts: 55
Registered: ‎06-07-2007

Speed restriction?

I recently (4 days ago) moved my router as close as possible to the master socket which has improved the sync. rates, SNR, attenuation etc substantially. However, the actual speeds I'm seeing with various online speed tests (including MyBroadbandSpeed) are much lower than I would expect. I am aware that it can take a while for BT to update the IP profile and have read THIS.
I have run BT's speed test and get the following results:
IP profile for your line is - 6500 kbps
DSL connection rate: 448 kbps(UP-STREAM)  8128 kbps(DOWN-STREAM)
Actual IP throughput achieved during the test was - 2717 kbps

2717 kbps matches the range of speeds I'm seeing with the other speed tests. I'm hoping that the value will increase beyond 6500 kbps if the sync. rates remain stable.
Looking at the IP profile rate on the PlusNet page I (still) see:
Your current broadband speed is 3000 Kbps
Is it possible that PlusNet have clamped my connection to 3000 Kbps? If so, can someone reset it please? Smiley
TIA
Edit: Here are some stats from my utility for completeness:
Router Stats Logger v1.0.23 report - 18 May 2008 12:07:30
DS rate: 8128 kbit/s
US rate: 448 kbit/s
Max DS rate: 8128 kbit/s
Max US rate: n/a
DS SNR: 9 dB
US SNR: 28 dB
DS Attn: 21 dB
US Attn: 9 dB
DS Power: 19 dB
US Power: 12 dB
As one can see, the SNR and attenuation levels are OK.
13 REPLIES
Plusnet Alumni (retired) orbrey
Plusnet Alumni (retired)
Posts: 10,540
Registered: ‎18-07-2007

Re: Speed restriction?

Hi Neo,
Your BT profile has indeed been lifted, not sure why we didn't pick up the change here. I've manually adjusted this now so if you powercycle the router you should get a better speed.
Sorry for the hassle there, hope that helps.
Neo
Grafter
Posts: 55
Registered: ‎06-07-2007

Re: Speed restriction?

Many thanks for your reply and for updating the profile in the member centre, Matt Smiley
It now reads: Your current broadband speed is 6500 Kbps
I power-cycled my router and the speed has improved a little (see the attached image) as it has gone over 3000 kbps for the first time since moving the router (reaching 3429 kbps). However, it's still lower than one would expect isn't it? Undecided
I'll do some more tests, but it is possible there is some other throttling or restriction going on? Huh
Plusnet Alumni (retired) orbrey
Plusnet Alumni (retired)
Posts: 10,540
Registered: ‎18-07-2007

Re: Speed restriction?

I don't think so, your usage is fine though there may be exchange contention possibly?
I'd suggest having a search through these forums (maybe also http://www.kitz.co.uk) and looking for MTR tweaks as that may well help... unfortunately it's not something I can advise on myself as I've not tried it as yet (currently on cable).
Hope that helps,
MickKi
Grafter
Posts: 543
Registered: ‎30-09-2007

Re: Speed restriction?

Yes, at 3429 kbps it is lower than what you would expect.  I'm guessing that with a profile of 6500 kbps and a fair wind you should be seeing throughputs of more than 6000 kbps.  Check your BT exchange contention (can't remember where the link for this is on the PN portal), or try running a BT speedtest really early in the morning or late at night.
The above will not resolve the problem of contention at that test server.  Therefore it may be better to try a download from a UK mirror site and see what throughput you can achieve then.  You could also try this link.
Hope this helps.
Community Veteran
Posts: 1,987
Thanks: 5
Fixes: 3
Registered: ‎01-08-2007

Re: Speed restriction?

Try this link from Kitzs site  http://www.kitz.co.uk/adsl/tweak2.htm
Scroll down to where it says dslreports have a tweaktester, and try that. Its possible you are not correctly set up for faster speeds, XPs defaults are nowhere near where you need them to be. ( I am assuming you are running XP, vista does it all differently).  Kitz has some explanations on vista MTU etc
MickKi
Grafter
Posts: 543
Registered: ‎30-09-2007

Re: Speed restriction?

[Message deleted - by mistake I answered to the wrong thread!]
Neo
Grafter
Posts: 55
Registered: ‎06-07-2007

Re: Speed restriction?

Thanks for the replies, everyone Smiley
I have tested many MTU and RWIN settings today and continued to perform speed tests on multiple websites. I'm now getting around 5500 kbps which is more reasonable but I have found that the RWIN and MTU don't make a huge difference (the speed varies more between different times of the day which can be down to contention etc as already mentioned).
Past experience has shown that MTU values can be more significant to people if certain websites become unavailable, but that doesn't apply in my case Wink
Community Veteran
Posts: 3,789
Registered: ‎08-06-2007

Re: Speed restriction?

5500 Kbps on a 6500 Kbps profile is 'about right' - the rest is likely to be due to overheads and exchange contention.
I found the biggest factor in tuning my connection to be the RWIN figure, which practically doubled my connection speed.  I'm on an 8128k BBYW Pro and I think I can (at absolute MAX!) get around 6700 Kbps download on a 7150 profile
B.
Neo
Grafter
Posts: 55
Registered: ‎06-07-2007

Re: Speed restriction?

Update:
As expected with my improved connection characteristics, my (BT) IP Profile has increased:
    IP profile for your line is - 7150 kbps
    DSL connection rate: 448 kbps(UP-STREAM)  8128 kbps(DOWN-STREAM)
    Actual IP throughput achieved during the test was - 4135 kbps

My PlusNet profile still says:
    Your current broadband speed is 7000 Kbps
So could someone give my PN profile a nudge again (to 7150 Kbps), please? Smiley
I know 150 Kbps isn't a big deal, but still, every little helps Smiley
[quote=Barry Zubel]I'm on an 8128k BBYW Pro and I think I can (at absolute MAX!) get around 6700 Kbps download on a 7150 profile
I'm disappointed to discover that despite syncing at the maximum 8128 kbps and maintaining a decent SNR margin etc that it's still not possible to achieve the maximum "8 MB" throughput. So all the "up to 8MB" advertising that people are complaining about should actually be "up to about 7MB" anyway Sad
Plusnet Alumni (retired) orbrey
Plusnet Alumni (retired)
Posts: 10,540
Registered: ‎18-07-2007

Re: Speed restriction?

Hi Neo,
The BT systems show your profile as being 7000kbps since the 23rd May so there wouldn't be anything gained from upping your profile at this end.
Sorry for the hassle,
Superuser
Superuser
Posts: 9,815
Thanks: 1,189
Fixes: 68
Registered: ‎06-04-2007

Re: Speed restriction?

Quote from: Neo
I'm disappointed to discover that despite syncing at the maximum 8128 kbps and maintaining a decent SNR margin etc that it's still not possible to achieve the maximum "8 MB" throughput. So all the "up to 8MB" advertising that people are complaining about should actually be "up to about 7MB" anyway Sad

Sorry, your interpretation of the numbers is incorrect.
8128kbps is the datagram (bit-rate) you get. Subtract approximately 10% for ATM transmission overheads and another 3% for TCP/IP overheads and you get 8128 x 0.9 x 0.97 = 7096kbps idealised throughput rate. BTW call this the IP Profile and make it 7150kbps. The actual throughput is less than that due to the effects of data integrity management.
So the throughput really is 8128kbps, it's just that not all of it can be user data.
David
MickKi
Grafter
Posts: 543
Registered: ‎30-09-2007

Re: Speed restriction?

Quote from: Neo
Update:
As expected with my improved connection characteristics, my (BT) IP Profile has increased:
    IP profile for your line is - 7150 kbps
    DSL connection rate: 448 kbps(UP-STREAM)  8128 kbps(DOWN-STREAM)
    Actual IP throughput achieved during the test was - 4135 kbps


A BT IP Profile of 7150 is the highest that you could attain under ADSLMax.  The throughput is clearly lower that what you should be seeing and this probably indicates contention at the BT exchange and, or contention at the BT Speetest server and, or high internet traffic.  What throughput speeds do you get when you run a test really early in the morning - say at 06:30?  If it's not 6000+ kbps then your computer tcp/ip settings or perhaps your router MTU, would need some tweaking no doubt.
Neo
Grafter
Posts: 55
Registered: ‎06-07-2007

Re: Speed restriction?

Quote from: orbrey
The BT systems show your profile as being 7000kbps since the 23rd May so there wouldn't be anything gained from upping your profile at this end.
Thanks for the reply, but I have been using the BT Speedtester frequently since then and it repeatedly reports:
IP profile for your line is - 7150 kbps
    DSL connection rate: 448 kbps(UP-STREAM)  8128 kbps(DOWN-STREAM)
    Actual IP throughput achieved during the test was - 4458 kbps
but the PN profile is still stuck on 7000 kbps.
Quote from: spraxyt
Sorry, your interpretation of the numbers is incorrect.
8128kbps is the datagram (bit-rate) you get. Subtract approximately 10% for ATM transmission overheads and another 3% for TCP/IP overheads and you get 8128 x 0.9 x 0.97 = 7096kbps idealised throughput rate. BTW call this the IP Profile and make it 7150kbps. The actual throughput is less than that due to the effects of data integrity management.
So the throughput really is 8128kbps, it's just that not all of it can be user data.
Thanks, I'm aware of the overheads involved, but my point is that the "up to 8MB" marketing spiel is still wrong because the maximum real data transfer speed that anyone will see will always be below 8000 kbps...
Quote from: MickKi
A BT IP Profile of 7150 is the highest that you could attain under ADSLMax.
Yep, I know Smiley
Quote from: MickKi
What throughput speeds do you get when you run a test really early in the morning - say at 06:30?
I get around the 6050 kbps mark (6500 kbps on Speedtest.net), so I think my MTU values don't need any further tweaking.