Compaq OSI/FTAM D43 - Manual (Page 35)

Compaq FTAM Responder Operation
OSI/FTAM Responder Manual— 425199-001
3 -3
Responder Data Flow
2. The FTAM initiator follows the OSI protocol established on the initiating system to
send the outgoing FTAM protocol data unit (PDU) over the network to the Compaq
responding system, where it is received as an indication.
3. Once on the Compaq responding system, the incoming FTAM indication is sent
through the NSP, TSP, and TAPS processes, where it is formatted and processed as
required by each OSI layer.
4. After processing the indication, the TAPS process sends the PDU through the
OSI/AS API to the protocol state machine of the responder.
5. The protocol state machine decodes and checks the validity of the indication and, if
the indication is valid, performs the requested action, communicating with the VFS
where file-system access is required.
6. .The VFS accesses the file system via standard procedure calls and informs the
protocol state machine when the requested file-system actions are completed.
7. Based on the outcome of the file-system actions, the protocol state machine encodes
and sends a response PDU to the TAPS process for transmission to the FTAM
initiator. This response contains any diagnostic messages resulting from its
checking of FTAM protocol or from VFS communication with the file system.
8. .The TAPS process formats the PDU and forwards it to the TSP process. The TSP
process, in turn, formats the PDU and sends it to the NSP process. The NSP
process, depending on the network protocol that it supports, formats the PDU and
forwards it via the appropriate controller (or adapter) over the network to the
initiating system, where it is received as a confirm.