found in IBM® Toolbox for Java™:
Commtrace classes
This figure illustrates in a general way
how the commtrace classes correspond to a communications trace file.
Description
The figure is composed of the
following:
- A square image in the right background labeled 'Prolog,'. This
square is divided into rows that represents a section of a communications
trace for a LAN line description. Written vertically on the left side
of the image is the word 'Frames'
- An image in the left foreground of a horizontal rectangle. This
rectangle is connected to the main square in the background by lines
on each side. The rectangle represents a frame in the trace file and
is divided into 3 sections:
- A green section labeled 24-bytes that represents the section of
data that contains general information about the contents of the frame.
- A light blue section labeled LanHeader that indicates the section
of data that contains general information about the IPacket that follows..
- A tan section labeled IPPacket that indicates the section of data
composed of one or more headers and the associated data.
- Another horizontal rectangle is below the first. A line on each
side of the rectangle connects it to the IPPacket. The rectangle represents
a detailed version of the IPPacket section and consists of 2 sections:
- A light blue section labeled Header that indicates the section
of data at the beginning of an IPPacket
- A dark blue section labeled Data that indicates the packet data
and points to the next header.
- A third horizontal rectangle appears below the dark blue Data
section. A line on each side of the rectangle connects it to the Data
section. The rectangle represents the 2 sections of the IPPacket and
states 'IPPacket information encapsulates a chain of other headers
and associated data':
- A light blue section labeled Header that indicates the section
of data at the beginning of an IPPacket
- A dark blue section labeled Data that indicates the packet data
and points to the next header.
A frame (first horizontal rectangle) in a trace file (background
image) contains 2 sections of data, the 24-byte section (green) of
data and the LanHeader (light blue), along with the packet (tan).
The
IPPacket (second horizontal rectangle) processed in the frame consists
of the Header (light blue) and Data (dark blue) which in turn point
to another header and data (third horizontal rectangle). The second
and third rectangles are joined by connecting lines on each side from
the Data section and back to the IPPacket which shows the continuous
chain for headers and associated data in a communications trace.