DSL service [was Re:TLUG Mail list archives?]

[Lennart Sorensen]

On Fri, Jun 08, 2007 at 02:00:36AM -0400, D. Hugh Redelmeier wrote:
> The "last mile" of all DSL providers is the same: Bell Nexia.

I have seen some ISPs support running on sprint phone lines too, so no
not quite everyone has to use bell for the last mile.  Just most.

> Do you know if the bottleneck is within Bell's network or Pathcom's?
> If it is within Bell's then you need to switch to Rogers :-(

It is almost certainly with the ISP.  The bandwidth in the DSLAM going
to the ISP access is very high.  I have certainly seen cases where one
DSL user was getting terrible speed and another using the same CO was
getting amazing speed on a different ISP.

> For example, my DSL connection is bad.  The problem appears to be that
> my wire to the Central Office is 5km, about the limit.

Well the distance certainly affect speed.  Some DSL models will tell you
their current connection speed, which can give an idea as to what the
speed is.  When I had DSL at an appartment a few years ago, the internal
wiring in the building was crap, and I was on the 21th floor.  I often
had the DSL connection drop out, and the speed was never great, but I
knew it was due to the crappy wiring.

> It is pretty hard to figure out where the problem is: nobody knows or
> if they do they don't want to tell you.
> 
> Usually you can ask your DSL modem about line quality and bandwidth
> limitations.  I don't know enough to know how to interpret them.

Well here is some values from one ADSL modem here:

        -------------------------------------------
                w3adsl: SIGNAL TO NOISE RATIO
        -------------------------------------------

        Local SNR Ratio :  31 dB
        Remote SNR Ratio:  5 dB

        ---------------------------------
                w3adsl: ATTENUATION
        ---------------------------------

        Attenuation:  20 dB

        ------------------------------------
                w3adsl: ADSL BAUD RATE
        ------------------------------------

        Down Rate: 3008 kbps : Interleave Buf
        Up   Rate: 800 kbps : Interleave Buf

        -----------------------------------
                w3adsl: REMOTE VENDOR
        -----------------------------------

        Remote Vendor (hex): 0f0042434c41

        ---------------------------------------
                w3adsl: XMIT POWER STATUS
        ---------------------------------------

        Local Attenuation :  6 dB
        Local Num of Bins :  23
        Remote Num of bins:  210

And much more too.  I don't really know how to make sense of a lot of
it either.

--
Len Sorensen
--
The Toronto Linux Users Group.      Meetings: http://gtalug.org/
TLUG requests: Linux topics, No HTML, wrap text below 80 columns
How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists