You can run the NCP/Token-Ring interconnection (NTRI) physical line trace and NTRI IOH trace using the same methods as the NCP line trace. The NTRI physical line trace and the NTRI IOH trace always run at the same time. To trace IOHs only (no line trace data), specify 0 for the COUNT parameter of the trace activation command.

NCP V6R2 and later

NTRI logical lines can also be traced. Only one type of NTRI line trace can be activated at a time. If an NTRI line trace is active, either physical or logical, a second activation request for NTRI physical or logical line trace is not allowed. The NTRI logical line trace can be activated on a logical line that is not active, but no data is traced until after a connection that uses the logical line has been established and link-level data is transmitted. For incoming connections, the following data is not traced:

• Test command sent by the device
• Test response sent by NCP
• First XID sent by the device

For outgoing connections, the test response from the adjacent station is not traced, but the test command sent by NCP and all other data that follows the test response from the adjacent station is traced.

The NTRI IOH trace records the IOHs dedicated to a particular TIC and the token-ring multiplexer (TRM) that controls the TIC. Only those IOHs issued by level 2 and level 3 NTRI code are traced. IOHs that are tried again by level 1 NTRI code are not traced, but because they are tried again, a box event record (BER) is produced and sent to the maintenance and operator subsystem (MOSS).

NCP V5R3 and later

For the NTRI physical line trace, the COUNT parameter of the trace activation command specifies the amount of data to be traced. If the value of COUNT is a value in the range 200 to 254, 200 bytes are traced. If the value of COUNT is 255, 38 bytes (the default) are traced. Specify 0 for COUNT to trace IOHs only (no line trace data).

NTRI line trace and NTRI IOH trace elements appear in chronological order. When the trace elements are edited, the NTRI IOH trace elements get a specific header to distinguish them from the NTRI line trace elements. For information regarding the trace element formats, see NCP and EP Reference Summary and Data Areas LY43-0030.