#8 add Ending Diameter activity explicitly from SBB function

[xphudin]

hi @brainslog @deruelle
I have just finished the work discuss before on that issue.
Can you please review it?
Thanks

[deruelle]

Thanks @xphudin ! @brainslog can you please review ?

[SergeyLee]

Hi @xphudin @brainslog !
Can we realize this ending on Diameter protocol level?
What about expiration (and expiration time)?
As I read spec 8.4. Session Termination:

When a user session that required Diameter authorization terminates,
the access device that provided the service MUST issue a Session-
Termination-Request (STR) message to the Diameter server that
authorized the service, to notify it that the session is no longer
active. An STR MUST be issued when a user session terminates for any
reason, including user logoff, expiration of Session-Timeout,
administrative action, termination upon receipt of an Abort-Session-
Request (see below), orderly shutdown of the access device, etc.