CSS adapter trace

The CSS adapter trace gathers information from the 3746 Model 900 hardware. The trace contains two types of information:

  • Component-to-component inside the 3746 Model 900
  • Information flowing from the 3746 Model 900 to your network

You can use this trace to record data from either or both of the following sources:

  • The controller bus processor:
    • Controller bus and service processor (CBSP)
    • Controller bus and token ring processor (CBTRP))
  • The target processor:
    • Token ring processor (TRP)
    • Communication line processor (CLP) which supports; SDLC, frame-relay, ISDN, and X.25 lines
    • ESCON processor (ESCP).

Activate and deactivate this trace from the VTAM® console as a SIT.

CSS adapter trace can be started for a high speed line only when CSS adapter trace is not active for any other line (high speed or low speed). 3746 Model 900 lines that are considered high speed are:

  • Logical and physical ESCON or token-ring lines
  • SDLC, frame-relay, ISDN, or X.25 lines with SPEED=1048576 or greater on the LINE definition statement
  • A logical frame-relay line that does not have the SPEED keyword coded but has an associated physical line that is coded with SPEED=1048576 or greater

You can request a trace of a logical or physical line. Physical line trace data includes commands for the physical line and for the associated logical lines. Logical line trace data includes only commands and associated data directed to logical resources for that line.

For integrated services digital network (ISDN), you can request a trace of a logical, B-channel, or physical line. Physical line trace data includes commands for the physical line, the associated B-channel lines, and the associated logical lines.

B-channel line trace data includes commands for the B-channel line and the associated logical lines. Logical line trace data includes only commands for the logical line.

The data from this trace helps you isolate a problem. You can use it with the CSS line trace data to determine if a problem is with NCP, the controller bus processor, or the target processor

When NCP enters pseudo-slowdown, it suspends the transfer of CSS SIT trace data from the CSS to NCP. As long as NCP continues to operate in pseudoslowdown, the CSS suspends all trace activity and enters a trace data lost message in the SIT trace data records. The SIT trace terminates if NCP enters slowdown, receives a deactivation request, or trace activity is suspended for more than three minutes. If NCP exits pseudo-slowdown to continue normal processing, it resumes the transfer of CSS SIT trace data from the CSS.

Figure 1 shows the relationship of the 3746 Model 900 CSS adapter trace to NCP and to the hardware. For more information, see CSS line trace.

Figure 1 also shows the MODIFY TRACE trace-point values for each of the two sources. You can request a trace of both sources by specifying TRACEPT=3 on the MODIFY TRACE command.

Figure 1. Relationship of the CSS adapter trace to NCP and to the 3746 Model 900 hardware
Relationship of the CSS adapter trace to NCP and to the 3746 Model 900 hardware

ISDN physical lines represent both the ISDN D-channel and the entire physical connection to the ISDN network. To collect only ISDN D-channel signaling information, TRACEPT=4 can be specified for an ISDN physical line.

For more information about the MODIFY TRACE command, see z/OS Communications Server: SNA Operation. For sample reports, see CSS adapter trace reports.