Why is throughput speed much lower than the IP Profile?

Hi,


I currently have an IP Profile of 7150kbps but the maximum I have ever managed to get out of it is 6783kbps at 3 in the morning. Is there any explanation for this?

If I tweak my router settings so I can get a lower SNR (DG834GT) then will I achieve better throughput speeds?

I'm on an exchange that serves around 1500 lines so congestion is not the problem.

Thanks

Forgot to say that my attenuation is 15dB

You will never achieve the full IP profile in terms of download speed - only approx 95% or so due to various overheads - so your speed test is spot-on for your connection speed.

You are already on the highest IP Profile for standard ADSL - so tweaking won't help.

As others are saying your actual throughput will always be slightly lower than your profile due to 'overheads'.

If you are connected wirelessly try a cable as this will give you your best results.
My IP Profile is 4500 and a speed test shows I'm getting 4360 at the moment - pretty close.

A lot is also down to your ISP and how much they are throttling users during busy times.

As others have said your download speeds are what you would expect for a profile of 7150kbps. I'd count anything over 6500kbps as very good.

I know but I always thought that the overheads were the difference between the profile and sync speed?

The profile accounts for the ADSL overheads (ATM etc.) to go from the sync rate (say 8128) to the profile (say 7150).

There are TCP overheads of approximately 5% to go from the profile (say 7150) to the maximum application data rate (say 6800).

Can anyone help? After 6 years of broadband with AOL without problem, the last few months have been terrible. Slow speeds woulld be an understatement. AOL suppport have been useless, saying only this evening that my telephone line won't support more than 0.5 meg - how has it done so for 6 years then? Yet another speedtest this evening shows -

Download speedachieved during the test was - 214 Kbps
For your connection, the acceptable range of speeds is 600-7150 Kbps.
Additional Information:
Your DSL Connection Rate :5312 Kbps(DOWN-STREAM), 448 Kbps(UP-STREAM)
IP Profile for your line is - 4500 Kbps

Any ideas what is going on and what I can do next? I would be grateful for amy help. Thanks

It may be a contention issue or VP Capacity Issue. What exchange are you on? I'll do some checks for you.

As a response to the Original post on this thread, look at my speedtest below - I have the full 7150kbps profile so I guess that 6783kbps is around the best throughput you can get

Edited by chris6273 (Mon 19-Apr-10 23:57:42)

Thanks for the response!! My exchange is Fishponds, Bristol. I am just about at the end of my tether with AOL, I can't face another call to their 'help desk' to be told there is nothing they can do and why not get cable!!!!! If I have had broadband succesfully for 6 years, how is it possible that it is not possible now? Any help would be gratefully received.

Ann