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 thesection 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.