[Serusers] Asterisks to ser to asterisk (voicemail)

[Juha Heinanen]

if asterisk were a sip proxy, it should accept the same request several
times as long the request uri of the request changes, i.e., the request
spirals.  if it is a sip proxy, it should act like a b2bua and terminate
each iteration of the request.  the loop detected stuff thus seems like
asterisk's problem that it hard to solve in ser.

-- juha