According to the AD integration guide:
A client application initiates an SOL or IDE-R session with an Intel AMT device by calling either IMR_IDEROpenTCPSession or IMR_SOLOpenTCPSession both are functions in the redirection library. These functions have as input parameters the username and password of the client. The library opens a socket with the Intel AMT device and negotiates the protocol to be used between them. If the SOL/IDE-R authentication was enabled, then the library will attempt to contact a ticket granting server for establishing a Kerberos connection. If this fails, the library will attempt to connect using the username/password combination.
So is it correct that only kerberos authentication credentials of current windows user can be used for SOL/IDE-R? Can I specify the credential (domain, user, password) of other user for SOL/IDE-R library?