Library /sys$common/syshlp/tracehlp.hlb START, /SESSION  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    /NOSESSION
    /SESSION=(session-range,...)

    A list of SNA session numbers and ranges.  Only trace  records  for
    selected  sessions  will  be  displayed.  Each session range can be
    either a single value, or a range of values, or *.

    /NOSESSION will select trace records on all sessions.

    For  example  /SESSION=(1,%xA-*)  selects  session  1  and  session
    numbers greater than or equal to 10 (decimal).

    This qualifier is only valid for SNA PU trace records.