----- Original Message -----

From: "Paul Lettington" <paul@plett.co.uk>

On Fri, Oct 21 2011 08:10:02 -0500, Frank Bulk wrote:

...

Why did a 15-minute outage cause subtended customers to be out for much longer than that?

Because BT's RADIUS servers which look at the realm of the login and route the session to the correct ISP are unable to cope with the load of all the ADSL users in the country continually reconnecting during an outage like this.

So when BT can't connect the end user to the ISP they accept the end user's session themselves with a RFC1918 IP address for exactly an hour and not connected to the internet, to stop them trying to log in.

Sounds to me like they need to change that to "15 minutes + 1 minute * rand(10) Cheers, -- jra -- Jay R. Ashworth Baylink jra@baylink.com Designer The Things I Think RFC 2100 Ashworth & Associates http://baylink.pitas.com 2000 Land Rover DII St Petersburg FL USA http://photo.imageinc.us +1 727 647 1274