Turn on suggestions
Auto-suggest helps you quickly narrow down your search results by suggesting possible matches as you type.
Showing results for
How is the IP Profile and actual D/L speeds determined ?
Topic Options
- Subscribe to RSS Feed
- Mark Topic as New
- Mark Topic as Read
- Float this Topic for Current User
- Bookmark
- Subscribe
- Printer Friendly Page
- Plusnet Community
- :
- Forum
- :
- Help with my Plusnet services
- :
- Broadband
- :
- Re: How is the IP Profile and actual D/L speeds de...
How is the IP Profile and actual D/L speeds determined ?
21-07-2013 10:03 AM
- Mark as New
- Bookmark
- Subscribe
- Subscribe to RSS Feed
- Highlight
- Report to Moderator
I'm just curious ....
How is the IP profile speed calculated ? Is it done based on some "theoretic" set of data ie an estimate of line length or based purely on observed values ?
Is there something in my current line stats (FTTC connection in my case) that allow me to make the same calculation ? Or is there something else you need to know ?
One you can calculate the IP profile, what is it that determines the actual line speed ?
For example on the above stats, i get a profile of 50.9Mbs but the max download i currently see is 44Mbs .... so what determines the difference between the two. Is it an effect of the line latency (c 26ms) ?
Andy
PS - i'm not sure i total trust the above numbers as it implies my line is fast pathed but PN tell me it's interleaved .....but if nothing else it's a
How is the IP profile speed calculated ? Is it done based on some "theoretic" set of data ie an estimate of line length or based purely on observed values ?
Is there something in my current line stats (FTTC connection in my case) that allow me to make the same calculation ? Or is there something else you need to know ?
> adsl status
--------------------------- ATU-R Info (hw: annex A, f/w: annex A) -----------
Running Mode : unknown State : SHOWTIME
DS Actual Rate : 52640000 bps US Actual Rate : 20000000 bps
DS Attainable Rate : 0 bps US Attainable Rate : 0 bps
DS Path Mode : Fast US Path Mode : Fast
DS Interleave Depth : 0 US Interleave Depth : 0
NE Current Attenuation : 17 dB Cur SNR Margin : 6 dB
DS actual PSD : 7. 5 dB US actual PSD : 12. 5 dB
ADSL Firmware Version : 05-04-08-00-00-06
-------------------------------- ATU-C Info ---------------------------------
Far Current Attenuation : 0 dB Far SNR Margin : 6 dB
CO ITU Version[0] : 00004d43 CO ITU Version[1] : 000015a4
DSLAM CHIPSET VENDOR : < unknown >
One you can calculate the IP profile, what is it that determines the actual line speed ?
For example on the above stats, i get a profile of 50.9Mbs but the max download i currently see is 44Mbs .... so what determines the difference between the two. Is it an effect of the line latency (c 26ms) ?
Andy
PS - i'm not sure i total trust the above numbers as it implies my line is fast pathed but PN tell me it's interleaved .....but if nothing else it's a
Message 1 of 5
(1,172 Views)
4 REPLIES 4
Re: How is the IP Profile and actual D/L speeds determined ?
21-07-2013 10:21 AM
- Mark as New
- Bookmark
- Subscribe
- Subscribe to RSS Feed
- Highlight
- Report to Moderator
IP profile on 21CN is calculated from sync speed multiplied by .882
IP Profile on fibre is calculated from sync speed divided by 1.033
IP profile on 20CN is taken from a look up table http://www.kitz.co.uk/adsl/IPprofile.htm
Sync speed is normally determined by the default noise margin at sync point
The other factor is the Plusnet value for current line speed here https://portal.plus.net/my.html?action=data_transfer_speed
IP Profile on fibre is calculated from sync speed divided by 1.033
IP profile on 20CN is taken from a look up table http://www.kitz.co.uk/adsl/IPprofile.htm
Sync speed is normally determined by the default noise margin at sync point
The other factor is the Plusnet value for current line speed here https://portal.plus.net/my.html?action=data_transfer_speed
Message 2 of 5
(572 Views)
Re: How is the IP Profile and actual D/L speeds determined ?
21-07-2013 10:31 AM
- Mark as New
- Bookmark
- Subscribe
- Subscribe to RSS Feed
- Highlight
- Report to Moderator
Ok great ... that works.
So ...
How does the sync speed get determined ? I can't believe it tries lots of different speeds each time there's a connection ... or does it ? (is the Training phase ?)
So given that's the IP profile value .... what determines the difference between the that and the actual achieved DS speed ?
So ...
How does the sync speed get determined ? I can't believe it tries lots of different speeds each time there's a connection ... or does it ? (is the Training phase ?)
So given that's the IP profile value .... what determines the difference between the that and the actual achieved DS speed ?
Message 3 of 5
(572 Views)
Re: How is the IP Profile and actual D/L speeds determined ?
21-07-2013 10:33 AM
- Mark as New
- Bookmark
- Subscribe
- Subscribe to RSS Feed
- Highlight
- Report to Moderator
Quote from: Oldjim Sync speed is normally determined by the default noise margin at sync point
The other factor is the Plusnet value for current line speed here https://portal.plus.net/my.html?action=data_transfer_speed
Isn't by 6db SNR value pretty good ?
But the value reported there is my ip profile speed.
Estimated line speed:
There's no speed estimate currently held on your account.
Current line speed:
50.8 Mb
Message 4 of 5
(572 Views)
Re: How is the IP Profile and actual D/L speeds determined ?
21-07-2013 10:37 AM
- Mark as New
- Bookmark
- Subscribe
- Subscribe to RSS Feed
- Highlight
- Report to Moderator
The Plusnet current line speed is the IP profile rounded down BUT it doesn't autromatically update when the sync speed changes. It waits for a Delta report whicch sometimes doesn't arrive
The default noise margin starts off at 6dB then either increases in 3dB steps until the line is stable or on a good line reduces to 3dB - this is on 21CN but I haven't seen any definitive answer with respect to fibre as that is all handled at the Cab not the exchange
The default noise margin starts off at 6dB then either increases in 3dB steps until the line is stable or on a good line reduces to 3dB - this is on 21CN but I haven't seen any definitive answer with respect to fibre as that is all handled at the Cab not the exchange
Message 5 of 5
(572 Views)
Topic Options
- Subscribe to RSS Feed
- Mark Topic as New
- Mark Topic as Read
- Float this Topic for Current User
- Bookmark
- Subscribe
- Printer Friendly Page
- Plusnet Community
- :
- Forum
- :
- Help with my Plusnet services
- :
- Broadband
- :
- Re: How is the IP Profile and actual D/L speeds de...