*** preliminary documentation for MiamiRemind BETA ***


Some users consider the automatic warning and disconnect
after 30/60 minutes in the Miami demo version a useful
feature, to save telephone/ISP costs.

MiamiRemind is a tool that introduces this kind of
functionality in the registered version of Miami, but in
addition to the simple warning/disconnect it offers
several other useful features:

 - The number of warnings, plus the interval between
   subsequent warnings can be freely configured.
   
 - It is possible to disconnect after a certain amount
   of time, to only display a finite number of warnings
   (without disconnecting) or to keep displaying warnings
   at regular intervals.

 - In addition to fixed time intervals it is possible to
   show warnings after a certain amount of *inactivity* on
   the link. Both types of warnings (warnings after fixed
   amounts of time and warnings after inactivity) can be
   enabled at the same time.

 - Using the inactivity timer directly with the "disconnect"
   option provides the functionality of a "disconnect on
   inactivity" option, something many users have requested
   for Miami.
   

The term "inactivity" is difficult to define for a TCP/IP
connection. The default definition used by MiamiRemind is
"lack of TCP traffic". With this definition MiamiRemind
requires extremely little overhead and memory.

For users who need more sophisticated definitions of
"inactivity", MiamiRemind provides an expression parser
and compiler identical to the one in MiamiTCPDump, i.e.
you can e.g. use expressions like

 "(tcp[13] & 3 != 0) or udp"

The above expression would consider all TCP SYN packets,
all TCP FIN packets, and all UDP packets "activity".
All other packets are not considered.

The expression parser/compiler requires miamibpf.library
and miamipcap.library, and thus introduces slightly higher
memory and cpu overhead than the hardcoded "TCP traffic"
definition.


Usage:	MiamiRemind [-f fixed_timer_spec]
                    [-i inactivity_timer_spec]
                    [-p pcap_spec]


Option "-f" defines the parameters for the fixed timer, i.e.
the timer that starts when MiamiRemind is started, without
considering activity on the link. The default is to disable
the fixed timer.

Option "-i" defines the parameters for the inactivity timer.
This timer is reset to zero whenever a packet is transmitted
or received that is considered "activity" on the link. The
default is to disable the inactivity timer.

Option "-p" defines the inactivity expression, in MiamiPCap
format (see the example above). The expression should be
enclosed in double quotes ("). If this parameter is
specified then MiamiRemind uses miamipcap.library and
miamibpf.library to parse, compile and evaluate the
expression. Otherwise the hardcoded definition
"TCP traffic" is used, and both libraries are not needed.


"timer_spec" (for options "-f" and "-i") is a string
that consists of numbers representing time intervals
(measured in minutes), separated by commas (",").

Each time interval in the string represents the delay
between subsequent events.

"event" usually refers to a warning requester. However
it is also possible to prefix numbers with the letter
"D", to indicate that MiamiRemind should disconnect the
line at the next event, or with the letter "L", to
indicate that MiamiRemind should loop, i.e. use the
next time interval repeatedly, to define a sequence of
events.


Examples:

MiamiRemind -f 30,D30

  This is identical in behavior to the demo version of Miami,
  i.e. show a warning after 30 minutes, and disconnect after
  another thirty minutes.

MiamiRemind -f 30,20,L10

  Display a warning after 30 minutes, then again after 20
  minutes, and from then on every 10 minutes (loop). Never
  disconnect the line.

MiamiRemind -f 60,60 -i L10

  Display a warning after 60 minutes and another one after
  another 60 minutes. After that disable the fixed timer.
  Also show a warning whenever there have been multiples of
  10 minutes of inactivity (lack of TCP traffic) on the link.

MiamiRemind -i D30

  Disconnect the link after 30 minutes of inactivity
  (lack of TCP traffic).

MiamiRemind -i D20 -p "tcp or udp"

  Disconnect the link after 20 minutes of inactivity.
  "inactivity" refers to TCP or UDP traffic.



MiamiRemind automatically quits when the interface goes
offline (regardless of the reason), when Miami tries to
quit, when the program receives a Ctrl-C signal, or when
both timers are disabled.

The easiest way to use MiamiRemind is to start it directly
from Miami whenever Miami goes online, i.e. as
"run >nil: Miami:MiamiRemind [options]" in a Shell script
launched from Miami (configured in Events->Online).


MiamiRemind requires

- Miami 2.92c or higher (registered version)
- miamipcap.library 2.0 or higher
- miamibpf.library 2.0 or higher


MiamiRemind is © Copyright 1997 by Nordic Global Inc.
All rights reserved.

Please send comments to kruse@nordicglobal.com