ADSL2+ upload/download sync speed ratio ??

Connection issues, drop outs or speed related faults for ADSL and ADSL2+ services
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DirtDevil
Posts: 10
Joined: Sat Sep 15, 2012 11:20 am
Location: Warranwood

ADSL2+ upload/download sync speed ratio ??

Post by DirtDevil » Wed Sep 19, 2012 8:31 am

Hi All,

I am approximately 1.1km from my exchange and get a sync speed generally of 12600kb/sec download and 1020kb/sec upload(basically at the theoretical maximum). The upload speed is where I would expect it to be based on distance (damn fast !! :D ), the download side I would expect to sync somewhere around the 20mb+/sec. I have one cordless phone base station plugged into the line with a filter (not to sure if it is an ADSL2+ or just ADSL filter, but it is the filter that came with the Dlink) and I have a DLink DSL-502T (Gen II) modem in full bridge mode with my Asus RT-N66U router do all the auth.

There are numerous phone points around the house that are not in use and the wiring for the phones is..........interesting !!

Is it normal for me to connect at this speed from the exchange and can I do anything to make it faster ?

Is the ratio of upload/download speeds to be expected ??

Thanks,

Matt.

Dazzled
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Posts: 6003
Joined: Mon Nov 13, 2006 1:16 pm
Location: Sydney

Re: ADSL2+ upload/download sync speed ratio ??

Post by Dazzled » Wed Sep 19, 2012 9:36 am

It doesn't seem too bad to me (I can't get that rate for a similar distance), but to answer the second question first, ratio at your computer doesn't mean much, as (1) upload is capped at the exchange, and (2) upload is at lower frequencies and less affected by line conditions.

Obviously optimum speed depends on an optimal line, but the first question can get very technical indeed, particularly as you have "interesting" domestic wiring. Most people will let support look at their line for obvious faults which Telstra can/will rectify.

For your case, if you want to press on, you might read up on how an analogue line signal composed of many added frequencies is converted to digital in the modem, and the line tests performed. Say, http://en.wikipedia.org/wiki/G.992.1, and http://www.kitz.co.uk/adsl/adsl_technology.htm.

Then you will need to obtain from the modem your own HLog, QLN, SNR, and BPT results for every frequency bin (use the telnet interface). When graphed these can indicate local and distant radio interference, bridge taps, crosstalk and so on, which may be fixable defects. It's in the text books, but unfortunately the simplest on-line explanation I know of has been withdrawn. The final tabulated BPT (bits per tone) are the data determining the line speed. A very small number of modems (eg Billion) allow the user to set a parameter ("Coding Gain") for the final calculation - it alters the noise margin, and so risks instability as a side effect.

udara
Exetel Staff
Posts: 362
Joined: Thu Dec 17, 2009 11:06 am

Re: ADSL2+ upload/download sync speed ratio ??

Post by udara » Wed Sep 19, 2012 9:42 am

DirtDevil wrote:Hi All,

I am approximately 1.1km from my exchange and get a sync speed generally of 12600kb/sec download and 1020kb/sec upload(basically at the theoretical maximum). The upload speed is where I would expect it to be based on distance (damn fast !! :D ), the download side I would expect to sync somewhere around the 20mb+/sec. I have one cordless phone base station plugged into the line with a filter (not to sure if it is an ADSL2+ or just ADSL filter, but it is the filter that came with the Dlink) and I have a DLink DSL-502T (Gen II) modem in full bridge mode with my Asus RT-N66U router do all the auth.

There are numerous phone points around the house that are not in use and the wiring for the phones is..........interesting !!

Is it normal for me to connect at this speed from the exchange and can I do anything to make it faster ?

Is the ratio of upload/download speeds to be expected ??

Thanks,

Matt.
If your modem is connecting through a ADSL1 filter it could affect the speed that you sync with , therefore try connecting only the modem directly to the first main wall socket and see if there is any improvement to the downstream sync speed.

I cannot say if it is normal for you to connect at this speed from the exchange because it is not only the distance that you are from the exchange but also other factors such as quality of the copper and electrical interference etc. that will affect the maximum speed that you are able to sync with.
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DirtDevil
Posts: 10
Joined: Sat Sep 15, 2012 11:20 am
Location: Warranwood

Re: ADSL2+ upload/download sync speed ratio ??

Post by DirtDevil » Thu Sep 20, 2012 9:30 am

These are the sync details from the modem:-

Downstream Rate: 12020 kbps
Upstream Rate: 1019 kbps
Channel: Interleaved
Current Noise Margin: 5.9db (Downstream) 5.8db (Upstream)
Current Attenuation: 38.3 db (Downstream) 15.8 db (Upstream)
Current Output Power: 20.6 dBm (Downstream) 12.1 dBm (Upstream)
PVC Info: 8/35

The only figure IMO that seems out is the downstream attenuation.

I am reputably informed that the filter that came with the DLink modem is a very good one, but changing filters made no difference anyways.

shoner
Posts: 756
Joined: Mon Apr 20, 2009 2:50 pm

Re: ADSL2+ upload/download sync speed ratio ??

Post by shoner » Thu Sep 20, 2012 9:46 am

DirtDevil wrote:These are the sync details from the modem:-

Downstream Rate: 12020 kbps
Upstream Rate: 1019 kbps
Channel: Interleaved
Current Noise Margin: 5.9db (Downstream) 5.8db (Upstream)
Current Attenuation: 38.3 db (Downstream) 15.8 db (Upstream)
Current Output Power: 20.6 dBm (Downstream) 12.1 dBm (Upstream)
PVC Info: 8/35

The only figure IMO that seems out is the downstream attenuation.

I am reputably informed that the filter that came with the DLink modem is a very good one, but changing filters made no difference anyways.
It appears that the line attenuation is a bit off. I have done a port reset, can you plug your modem directly to the first wall socket with out any other devices being connected and let us know if there is a change.
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DirtDevil
Posts: 10
Joined: Sat Sep 15, 2012 11:20 am
Location: Warranwood

Re: ADSL2+ upload/download sync speed ratio ??

Post by DirtDevil » Thu Sep 20, 2012 9:54 am

shoner wrote:
DirtDevil wrote:These are the sync details from the modem:-

Downstream Rate: 12020 kbps
Upstream Rate: 1019 kbps
Channel: Interleaved
Current Noise Margin: 5.9db (Downstream) 5.8db (Upstream)
Current Attenuation: 38.3 db (Downstream) 15.8 db (Upstream)
Current Output Power: 20.6 dBm (Downstream) 12.1 dBm (Upstream)
PVC Info: 8/35

The only figure IMO that seems out is the downstream attenuation.

I am reputably informed that the filter that came with the DLink modem is a very good one, but changing filters made no difference anyways.
It appears that the line attenuation is a bit off. I have done a port reset, can you plug your modem directly to the first wall socket with out any other devices being connected and let us know if there is a change.
I will try and find which one is first when I get home tonight. I would assume its the one at the front of the house in the master bedroom, but one never knows in this rental !!

CoreyPlover
Volunteer Site Admin
Posts: 5922
Joined: Sat Nov 04, 2006 2:24 pm
Location: Melbourne, VIC

Re: ADSL2+ upload/download sync speed ratio ??

Post by CoreyPlover » Wed Sep 26, 2012 11:12 am

Some simple answers:
DirtDevil wrote:Is it normal for me to connect at this speed from the exchange and can I do anything to make it faster ?
Yes, that is quite normal. Your sync speeds are above average already, but as shoner pointed out there is some further potential to improve your downstream speeds, so the 12Mbps might increase somewhat.
DirtDevil wrote:Is the ratio of upload/download speeds to be expected ??
Yes, completely. Upstream has less noise because it operates at a lower freuquency, therefore it is easier to get a "full" upstream sync (of 1Mbps) than it is to get a "full" or "high" downstream sync.
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