[Serusers] if power failure happens in UA while call is in progress, Ser accounts wrong

[Ricardo Carvalho]

Meanwhile I was making my scripts for management of the accounting, I 
realized and after some call has been answered if the called party 
simply has a power failure or network failure, no BYE message ever gets 
returned to the other party, what results in the acc table in one ACK 
message and after that no more messages belonging to that call-id. This 
can mean erroneously that the call is still in progress eternally, 
resulting in an enormous  billing to the caller!!
This is a very serious issue! How can I protect my system from this kind 
of problems?

Thanks,
Ricardo.