Should 1800kbps sync speed equate to 1024kbps download?

I have just been off a call with my ISP over an issue which I seem to be making no progress with.

I have a Cisco 837 ADSL router that regularly syncs at 1800kbps, then retrains to 1500kbps before settling between 1500kbps and 1800kbps.

Irrespective of the final sync speed, my throughput is always 1024kbps or less when downloading.

I have raised this to my isp as an issue, as I have a second ADSL line with a different isp that syncs a bit higher, at 2042kbps, but which I regularly get around 1800kbps throughput when downloading.

My isp advises that the sync speed of 1800kbps is the maximum the line can support, which I have no issue with, however they appear to be unwilling to discuss the throughput of the line for downloads and indicate that it's pretty much it-is-what-it-is and that potential noise/line errors could be reducing the throughput.

I believe that it should have a better throughput than 1024kbps if the sync speed is stabilising at 1.5 to 1.8Mbps and if errors were an issue, my line would sync at a much lower speed after a few days.

Can anyone offer any advice on how I can deal with this or whether my assumptions are wrong before I give up on what has been an excellent isp and ask for a MAC code to move to a new isp.

Much obliged.

Is it a BT IP Stream Max connection? If so, you'll have to think about your profile too

http://www.kitz.co.uk/adsl/IPprofile.htm

A sync of 1800 will give you an IP profile of 1500. Can you run a BT speedtest and maybe a normal one, and paste the results.

Matt

Matt,

Attached are the test results.

I have also appended the current status of my ATM0 interface on the Cisco 837 which was reset a couple of hours ago. Threshold of the line indicates 97% capacity utilisation, which after a few days reaches 100% and line speed settles between the 1568 and around 1800.


BT SpeedTest

The speed test has completed on test server speedtester1.speedtester.bt.com for user <deleted> and you have downloaded a 1.7Mb file at a speed of

806kilo bits per second (Kbps), your service bandwidth will have been quoted to you in kilo bits per second.

SpeedTest.Net
Download : 0.93Mbps / Upload : 0.33Mbps

Cisco 837

#show dsl int atm0
ATU-R (DS) ATU-C (US)
Modem Status: Showtime (DMTDSL_SHOWTIME)
DSL Mode: ITU G.992.1 (G.DMT)
ITU STD NUM: 0x01 0x01
Vendor ID: 'ALCB' 'TSTC'
Vendor Specific: 0x0000 0x0000
Vendor Country: 0x00 0xB5
Capacity Used: 97% 76%
Noise Margin: 9.0 dB 12.0 dB
Output Power: 17.5 dBm 12.0 dBm
Attenuation: 59.0 dB 31.5 dB
Defect Status: None None
Last Fail Code: None
Selftest Result: 0x00
Subfunction: 0x15
Interrupts: 653 (1 spurious)
Activations: 2
Init FW: ASW_init_3_9_221.bin
Operartion FW: ASW_R3_9_221.bin
SW Version: 3.9.221
FW Version: 0x1A04

Interleave Fast Interleave Fast
Speed (kbps): 1568 0 448 0
Reed-Solomon EC: 327 0 26 0
CRC Errors: 7 0 0 0
Header Errors: 4 0 0 0

In reply to a post by conflict67:

Speed (kbps): 1568 0 448 0

OK. So that gives an IP profile of 1250..

Those speeds are what I would say you would see on such a profile. Maybe slightly higher.. but not much.

Changing ISP won't help much, if at all*. It your line that determines your IP profile.

Edit* changing to a LLU ISP may help even if you stick on a ADSL1 profile as you are now. You remove the IP profiling that BT, IMHO, stupidly enforce.

Matt

Edited by deleted (Wed 30-Sep-09 18:13:04)

Thanks Matt, I take your point on an LLU ISP, as my other line is LLU'ed with Sky.

I have already tweaked the hell of of the Cisco 837 IOS like noise-margin and tx/rx-gain settings to get the line syncing higher.

Before I embark on finding an alternative LLU supplier to Sky, there's nothing I can can get BT to do like tweak the gain, as the line is pretty unusable for streaming BBC iPlayer?

No, BT have a very over active DLM system, which, if it THINKS/sees your line generating errors, it'll notch up your SNR margin.

However, you're only on 9db, so the line can't be that bad - just distance.

LLU is the way to go with things like this. What is your exchange name, or code? www.samknows.com will tell you.

Matt

Been on Kitz and SamKnows, so got a choice of a few, Sky (done that), O2/BeThere and TalkTalk.

O2/BeThere say that I am in luck and they can take my order, but they estimate my line to be 0Mbps

TalkTalk, personally I'd rather not.

Hmmm, might push for O2, as they do offer a 30 day satisfaction guarantee where I can exit the contract if I am unhappy or the speed is 0Mbps.

Thanks for your help Matt.

In reply to a post by conflict67:

Hmmm, might push for O2, as they do offer a 30 day satisfaction guarantee where I can exit the contract if I am unhappy or the speed is 0Mbps.

Certainly the best option! They'll also help with SNR tweaks from dealing with them in the past!

Good luck

Matt