In our requirements we should treat whether a notification method works
across a firewire or not as a propertiy of the method, rather than something
that the requester specifies. This strategy is the same as we finally
evolved for the URL for Printers for secure vs. non-secure.
So the scenarios in the requirements document should indicate parenthetically
the property of across firewire vs non-firewall, rather than an input
from the requester.
Also some methods may be usuable for both across firewall and not, such as
e-mail and pagers, while other methods may only be used when they don't
cross firewalls.
Tom