I recently had to get an external dial-up modem working again when Adam Internet changed their dialup modem number, so while I was at it, I upgrade the laptop to 9.04. Of course the laptop has a built in modem and of course it's a Connexant model and of course the modem doesn't work, even with the paid for Linuxant driver (Linuxant have completely useless support), so the laptop is using an old external modem connected with a USB to serial adapter which works surprisingly well.

gnome-ppp

As the laptop is running Ubuntu, I installed gnome-ppp, which is really just a front-end for wvdial.

sudo apt-get install ppp-gnome

pppd permissions

By default the logged in user has no access to ppd which is launched by wvdial after a connection is established. The correct way to fix this is to give yourself "Connect to Internet using a modem" rights in "Users and Groups" (System->Administration), then reboot. This makes you a member of the dip group, providing access to pppd. The fast way to fix this simply to grant yourself permission to execute pppd. You don't need to do this if you've already done it the correct way.

sudo chmod +x /usr/sbin/pppd

chap-secrets and pap-secrets

These files are read-only by default, but the dialing process involves writing to them, so you'll need to grant yourself access rights.

sudo chmod a+rw /etc/ppp/pap-secrets
sudo chmod a+rw /etc/ppp/chap-secrets

User name

You need to use your full Adam Internet email address as the user name: {account name}@adam.com.au

Stupid mode

There is an option in gnome-ppp on the Setup dialog, options tab, called "Ignore Terminal Strings (stupid mode)". Tick this on so that pppd is started immediately after a connection is established. The Internet, as viewed through the glory that is Adam Internet dial-up, is a sight to behold!