Re: Impact of hardware with bad SNR & Attenuation

In article <43177a20$0$17463$ed2e19e4@xxxxxxxxxxxxxxxxxxxxxxxxxx>,
kraftee@xxxxxxxxxxxxxxxxxxxxxxx says...

> >
> > If the problems are with CPE (other than the mode/wiring/etc), what
> > are the best solutions? Eg if the problem is a washing machine or
> > scanner, is it proximity to the device that matters, or is it
> > electrical noise? Some hardware better than others at coping with the
> > noise? Do things like surge protectors or UPSs help?
>
> Nope none of the above will help, what may (repeat may) help is fitting
> a RF3 filter in line before the master socket, but even that isn't
> guaranteed, depending on high big the RF spike is...

Of course, the best way of helping this is identifying the offending
piece of equipment and promptly taking it to the local tip :)

This may become a point of tension if said piece of equipment is your
next door neighbour's 42" plasma screen TV...


> >
> > If I have sync but no IP, what does this mean? For that matter, what
> > does sync actually mean? What do all the "ACTIVATION" to "SHOWTIME"
> > actually statuses mean?
>
> Showtime is when the circuit is synch'd up, Activation I must be honest
> I cannot recall ever seeing (but it could mean that the monem/router is
> attempting to negotiate a connection with the exchange)..

Some modems (my old connexant being one) have different labels for the
different parts of the handshake sequence. I believe it goes Activation,
Training, Channel Analysis, Showtime or there abouts on the connexant.
Most will just tell you whether it's in synch or not.

For when you're in synch but can't obtain an IP address, this probably
means you're not getting connected to the username you've put in, or if
you have there are so many line errors your modem can't decypher what
the RADIUS server is trying to tell it. When the ADSL signal is fine and
there's no connectivity (no IP address) this can be caused by many
things - most likely settings in the router (VPI, VCI, username, realm
etc).

>
> Hopefully they would also test the line (from the exchange), for
> capacitance balance as well as the normal battery, earth, loop & low
> resistance test. Also they would check the exchange equipment under
> load, using artifical line extenders (plug in dongles), personally I
> always check with 80dB but some only use 60dB, which is no matter as
> either way it is putting a loading onto the DSLAM which could prove a
> problem into the DSLAM card you are connected to.

Yeah, the initial testing BT do will vary on what indicators are given
by the woosh test - if the copper line test indicates an obvious line
flaw on BT's side, it's unlikely an exchange frames check would be
performed to start with and an appointment might be booked directly.
However, what BT do once the ISP raises a fault to them is sometimes
quite mysterious (nay plain wrong in some cases but I won't dwell on
it).

>

>
> DO NOT call BT for any ADSL problems. >

I second this - unless there's significant noise on the voice line, or
the voice line isn't functional at all, any ADSL fault should be
reported to the ISP. Reporting to BT retail first will just delay the
ISP, who won't be able to raise a fault to BT wholesale until the PSTN
fault is cleared down, which sometimes doesn't happen correctly,
introducing more delays... *rolls eyes*

To the OP - you're very welcome to collate anything you find useful in
my posts and reproduce/paraphrase it as necessary.

--
Alex Crosby
.

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