ticket_lifetime param in krb5.conf - what's it used for?

[Peter McFarlane]

Hi,

Please excuse my ignorance, but what is the ticket_lifetime parameter in 
krb5.conf (in [libdefaults] section) used for? The documentation for 
krb5.conf doesn't say anything about it, and I can't find any references 
to it when I search the source code (for 1.3.1).

Also, what is the default unit for it? seconds? e.g. my file has:

[libdefaults]
...
ticket_lifetime = 24000

I'm assuming that's seconds?

Any info much appreciated.

Regards,

Peter