[Gllug] (OT) Demonic dropping out

Jason Clifford jason at ukfsn.org
Tue Jul 27 15:08:17 UTC 2010

On Sat, 2010-07-24 at 17:28 +0100, Don Williams wrote:
> MY ISP is Demon, I have a service coming through a BT line which we also
> use for telephony (without interruption).

You have an ADSL broadband service. It is delivered over a BT phone
line. It is perfectly possible for the BT phone line to be working but
for the broadband to have problems as ADSL requires a better quality of
signal to work at all than a phone line does.

> Some hours of talking over the helpline with a VERY difficult to
> understand Chinese lady brought her statement that the failure was at
> the BT Thamesmead telephone exchange, with mention of "O2". After much
> furious re-jugging of my router's software and something at Demon's end,
> a re-connection was made on Wednesday of this week. One of the "helpers"
> said, during all this, that the trouble affected "some 200-plus people".

Unfortunately failures of equipment at the exchange or network beyond
the exchange can and do happen. They tend to be treated as a priority
however they always take time to fix.

> This afternoon, without warning (after a session on Ubuntu's forum I did
> some printing, then went back to check for e-mail) I was without service
> even though the indicator light on my Belkin N (wireless model
> F5D7630-4A, wired) was solid blue and indicated connection!

I presume that means you had line sync but nothing else.

When this happens you should run through some basic checks to determine
exactly what the problem is. In order they are:

1. Check that you actually have line sync. The best check for this is to
login to your router and view the connection or WAN status page. If it
is showing a rate for download and upload speeds then you have line
sync. If you do not have line sync you should try replacing the
microfilter(s), disconnecting all other devices from the phone line,
ensure that the router is connected to the BT master socket directly
(not via an extension) and try replacing the router. If none of this
resolves the problem call your ISP and explain that you do not have line

2. Check whether your router has an WAN (public) IP address (assuming
dynamic allocation by your ISP). This will usually be on the routers
status page for the WAN/ADSL connection. If you have an IP address the
router is connected to the internet. If you do not have an IP address it
means there is no PPP session. Reboot the router - this will often reset
the session. If it does not connect call your ISP and explain that you
have line sync but no PPP session.

3. If you have an IP address but cannot connect to web sites, etc try
the following:

 a: use ping and/or traceroute (or mtr) to verify whether you can get 
    any throughput. Test against several public IP addresses that you 
    can reasonably expect will be working (,
    and are the UKFSN router, news.bbc.co.uk and 
    www.google.co.uk respectively) If you can get to these you have a 
    working internet connection. 
    If you cannot there is a routing problem either at your router or
    your ISP.

 b: If ping/traceroute works but you cannot get to web pages etc you 
    should check the name resolver settings on your system (on Linux/
    *BSD this is in /etc/resolv.conf) and try alternatives. Usually
    this will fix things. If not you might have a local firewall

> She warned that I might have a £200-plus charge to pay to have the line 
> checked if problems recurred. By BT, the people who
> were responsible for the failure in the first place, according to Demon!

Alas this is true with all xDSL services. The charge (usually about £144
+VAT) is what ISPs are charged by BT Wholesale for an engineer call out
where it is determined that there was no fault at the BT end. It is
something all ISPs will try to avoid as nobody wants to try explaining
why it is acceptable to a consumer.

I hope the above is helpful to you.

If you want to avoid dealing with overseas call centres you could follow
the advise given by others and switch to an ISP with UK call centres
such as UKFSN ;)

Jason Clifford		- Yes I run UKFSN
UK Free Software Network

Gllug mailing list  -  Gllug at gllug.org.uk

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