An entry in the csiSessionTable.
An entry in the session table is identified by a
virtual N-port and a session Identifier.
Each N-port is identified by the ifIndex,
Nport type and the VSAN id as described above
in the csiNportEntry.
The combination of the N-port and the sessionId
uniquely identifies a session.
Each session has the local N-port's WWN, remote
N-port's WWN and remote node's WWN as well as
remote N-port's FcId.