isdn-config fails to spot that an external agent has dialled
under the following scenario

I have two ISPs configured. Starting isdn-config and
connecting to the first works as expected.

If I now hang up using "isdnctrl hangup ippp0" from a
terminal window the fact that the link has gone down is
correctly spotted and the state goes to "offline". Re-dialling
ippp0 from the terminal is correctly tracked with the state
going to "online"

If I now manually dial my second ISP (with "isdnctrl dial ippp1")
the fact that there is an active connection is missed - the
state remains at offline.

As an aside it would be useful if isdn-config could indicate
which provider (or providers as there's no reason not to be
connected twice) are currently connected rather than just
"online" which could be any provider.