OSI/AS Configuration and Management Manual

OSI/AS Subsystem Description
OSI/AS Configuration and Management Manual—424119-001
7-5
TAPS Process
TAPS Process
The TAPS process accepts request and response primitives from the API, communicates
with the OSI manager process to request and control subdevices, and provides Session
Layer, Presentation Layer, and ACSE services.
Downward Information Flow
Requests are received by TAPS, from the API, as request and response primitives. The
TAPS provider replies with I/O completions (sometimes called replies). The following
trace record example (generated by the SCF TRACE command and formatted by
PTrace) shows a request from the API to the Session Layer:
Trace records for presentation and ACSE services provide similar information.
The TAPS process takes the request and response primitives and formats them as
SPDUs. It then forwards the SPDUs to the TSP process in file-system calls to the TSP
subdevice. The TSP process replies to these calls with standard I/O completions. (Error
0 means successful completion; error 140 means transport disconnection received.)
In addition, the TAPS process traces the primitive calls to the TSP process. The
following PTrace records show an example in which the TAPS process has enabled the
TSP subdevice to accept a transport connect request. The primitive is the transport
T-CONNECT attach. The actual file-system call is used as a WRITEREAD with a
message control word (MCW) of %H8000:
15:45:46:890 >000.090 #47 TAPS L5 USER
L5 Request Su Name #Z000002 Session ID 2
Request Addr %H000A496A Request Tag %H0001F67C
Request Code - 32767 (Attach Req)
local^addr: zappl^name.zlen = 6 zappl^name.zc =
000: 4C4F 4341 4C58 LOCALX
zpsap.zssel.zlen = 3 zpsap.zssel.zc =
000: 5555 0100
zpsap.ztsel.zlen = 5 zpsap.ztsel.zc =
000: 4444 4444 0100
zpsap.znsap.zlen = 6 zpsap.znsap.zc =
000: 4083 3311 1101
filename = \249.TSP1 #Z000002
15:45:47:730 >000.000 #58 TAPS L5 PROV
L5 Issue Transport Attach Su Name #Z000002 Session ID 2
Request ID %H000A496A MCW %H8000
15:45:47:740 >000.010 #61 TAPS L5 PROV
L5 Issue Writeread Su Name #Z000002 File ID %H000119C0 Tag %H00000001
DCB Addr %H001AD7DA Write Count 00002 Read Count 00034 FS Error 00000