Under PPP settings, there are options for fast and slow. Fast actually makes things worse, I can no longer connect reliably. Slow, on the other hand, results in a good connection. I was able to surf the web, but with the patience of a typical web page loading in 10 minutes.
The IBM dialer probably lacks the versatility of Injoy dialer, but on a better phone line, perhaps it would work.
The next question is how to switch from a failing Ethernet connection to the dialer? I expect to have to remove everything to do with Ethernet networking before activating the dialer. Is that right?
net stop messenger /y
net stop req /y
dhcpmon -t
ifconfig lan0 down
ifconfig lan0 delete
route -fh
arp -f