LSNA entry for local SNA record (Part 1)

This trace record is written each time data is read or written across an APPN host-to-host channel.

Byte (hex)

Contents

00–03

Record ID: C"LSNA"

04

ID is the primary address space ID (ASID). This field is 0 if the ASID is greater than X'FF'.

05

Control block ID of work element being written or read across the channel

06

Event Flags

Bit

Meaning

1... ....

The data unit being traced (FID2 data or control data) is the last data unit in the multipath channel (MPC) transmit block header just received. This bit has meaning only for inbound data.

.1.. ....

This data is control data. If off, this data is normal FID2 data traffic.

..1. ....

This trace entry contains the beginning of a new PIU/control data. If off, this data unit is the middle or end portion of a PIU. For outbound data, this bit will always be on (only the first part of PIU/Control data outbound is traced).

07

A 1-byte field that indicates the direction of the data unit flow:

• Code

  Meaning

  C"I"

  Data received inbound

  C"O"

  Data sent outbound

08–0B

TSCB address

0C–0D

Length of data being sent or received

0E–1F

This 18-byte field will map as follows:

• For control data
  • The 2-byte QLLC Header (indicating the type of the control data)
  • Up to 16 bytes of the remaining control data
• For FID2 data
  • The 6-byte FID2 TH header
  • A 3-byte RH if it exists
  • Up to 9 bytes of the remaining FID2 data (12 bytes if no RH)