[asterisk-users] Authentication best practice

[Roger Burton West]

I am working with a simple "follow-me"-style service: rather than have
something that rings several phones in turn, the user dials a number (in
the present implementation, unique to that user) to register his
presence at a particular extension.

What's the standard way to protect this from unauthorised use?
Voicemail()-style, where the user has to enter a PIN once the connection
is made? With a very long number, so that number and PIN can be
integrated in the phone's contact list? With a single central number,
where the each user has to enter his own unique identifier _and_ PIN?

Roger