4.3.8  

ITSP client user IDs 
 
The client user IDs are supplied by the ITSP as soon as you apply for Internet telephony access.
The ITSP client user ID includes the following:
 •   SIP user ID and password (both needed for authorization during registration)
 •   Authorization user (needed to authorize call signaling)
An ITSP phone number can be:
 •   an MSN-type ITSP phone number (geographic or non-geographic) or
 •   a station number range (system connection).