Selecting the data you wish to see displayed:

Display filters determine which of the frames in the
frame buffer will be shown on the screen or written to
a printer or file.  Frames not displayed are still in
the buffer, but will be invisible until the display
filters are changed.

You select which frames to display by specifying the
station addresses that must appear, one or more
protocol levels that must be present, and a pattern
which must be matched by each frame to be displayed.

Selecting an address filter:

In the From address field you can select a filter for
the source station address of frames to be displayed. 
Pressing ENTER allows you to select "any", to select a
particular station from the current list of names and
addresses, or to enter a new station address in hex and
supply a new name.

The To address field specifies the destination address
filter in a similar manner.

Selecting an address filter (continued):

You may select a combination of Broadcast or Non-
Broadcast frames for collection by checking the menu
items with those names.

Checking "Reverse direction" permits frames in either
direction between the "To" and "From" stations to be
displayed.

Protocol filters:

You may select any number of protocol interpretation
levels for display by checking their names. Each one
corresponds to one or more of the IEEE 802.2 SAPs
(Service Access Points), MAC (Media Access Control)
frames, and higher level protcols.

A frame must contain at least one of the selected
protocols in order for any view of the frame to be
displayed.  In addition, the summary view will show
only the selected protocols when not in "highest level
only" mode.

Pattern matching in frames:

A pattern is a 1 to 4 nibble (hex digit) value that you
enter, using the hex values 0, 1, 2, .... D, E and F
for specific four bit fields, and X for "don't care".

You may choose whether to include frames WITH the
pattern (select Equals) or WITHOUT the pattern (select
Not equals).

Pattern matching in frames (continued):

The offset for the pattern match may be specified to
begin either at the first byte of the frame ("Frame
relative"), or at the beginning of the LLC information
("Data relative").  The Data relative offset starts with
zero at the first byte following the source address and
optional routing information field.

"No frames selected for display"

This message means that although there are frames in
the buffer, the display filters that you have selected
have resulting in no frames being elegible for display.

The display options menu will appear on the screen, and
you should recheck the station filters, protocol
filters, and pattern match to see why all frames have
been eliminated.  

