HI all, Im working on a storage protocol which uses SCSI commands set as the command set and also the SCSI Task Management functions for processing the Task Management. The Architectural Model is based on SAM-5. The Command set is based on SPC-4 and SBC-3. I have some doubts in trying to understanding some SCSI terms and definitions. For using the send command transport protocol service request to request a initiator the following API is defined [1]Send SCSI Command (IN (I_T_L_Q Nexus, CDB, Task Attribute, [Data-in Buffer Size], [Data- out Buffer], [Data-out Buffer Size], [CRN], [Command Priority], [First Burst Enabled])) Here I want to know what relation does the I_T_L_Q tries to convey. from what it says in SAM-5 Specification section 4.8 tries to define the Nexus as " nexus represents a relationship between a SCSI initiator port, a SCSI target port, optionally a logical unit, and optionally a command." how do we convey this information in the above [1]. Also can someone help me in how to map the initiator-target relation to host-device structure? thanks. Warm Regards, Ravi Kulkarni. Warm Regards, Ravi Kulkarni.