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User Guide: IPNetMonitor Advanced Techniques and Information

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This section of the User Guide provides additional technical information for advanced users who want to get the most from IPNetMonitor. The following topics are covered:

Notes on IPNetMonitor Timing

These notes provide some further information on the timing data obtained using IPNetMonitor.

Both the Test Connectivity and Trace Route tool use the OTGetTimeStamp function to capture times accurate to less than a millisecond. Time stamps are taken just before calling Open Transport to send a packet, and again from the notifier function called by Open Transport when data is received. Since the receive time stamp is captured during interrupt processing, it should be largely unaffected by other application time processing such as scrolling in another window.

The Monitor tool uses STREAMS timer messages that are synchronized with the STREAMS environment to report the number of bytes sent and received each second. Even though the data is captured every second, the Monitor display is updated during normal application processing (SystemTask time) so may appear to stall if another application is holding the processor for an extended period. When the monitor window is again allowed to update, it will plot previously stored data for up to the last 30 seconds.

For those familiar with STREAMS programming, the Monitor tool only counts bytes in MDATA messages. MPROTO messages that specify protocol commands are not counted (though attached MDATA blocks are).

If you want to get a sense for your actual modem performance in bits per second, you can calculate this by dividing the number of bytes per second by 0.122 . This takes into account the bit level packetization of data bytes used by V.34 modems versus the serial asynchronous data stream that includes extra start and stop bits.

For example, I downloaded an already compressed file (so there is little further compression in the modem) from a fast server and got the following numbers:

Max bytes/sec: 4620

37.8 kbps

Ave bytes/sec: 3325

27.254 kbps

So my average bit rate using a 28.8k modem connection was about 27 kbps.


Customizing Monitor Graph Colors

A custom color lookup table is used for the Monitor graph colors so that the sliding grid used as the plot background is visible but does not compete with the plot foreground data. The use of a custom color lookup table may cause the screen to redraw on 8-bit 256 color displays when the Monitor window is opened and closed.

You can prevent this redrawing by deleting the 'clut' resource in the IPNetMonitor application file (Resource ID 134, "Monitor Plot Colors"). If no 'clut' resource is found, IPNetMonitor will use default colors from the standard 8-bit 256 color palette.

You can also customize the Monitor plot colors by editing this resource. The colors in the 'clut' resource correspond to the following display colors respectively:

  1. Large Monitor window background
  2. Large Monitor window grid
  3. Transmit data
  4. Receive data
  5. Running average
  6. Small Monitor window background
  7. Small Monitor window grid

If you make the grid color the same as the background color so that the grid becomes invisible, horizontal tick marks will be added to the top and bottom of the Monitor plot.


Launching URLs to Destinations in the Trace Route Table

You can perform a Whois query on a destination in the Trace Route table by selecting the corresponding row and pressing Cmd-I. If you have Internet Config, you can also launch URLs to other applications by pressing Cmd-1 through Cmd-4. The corresponding URL is determined from 'STR#' resource 142 "Helper GURL schemes". The following URL schemes are initially specified:

  1. telnet://
  2. http://
  3. <empty>
  4. <empty>

Thus you can launch a Telnet GURL to a destination in the Trace Route table by selecting the corresponding row in the Trace Route table and pressing Cmd-1.


Using IPNetMonitor with Apple Internet Address Detectors

Apple Internet Address Detectors allow you to recognize Internet Addresses such as email, a host address, or URL in your documents and then take action on that information. For example, you can select any text containing one or more Internet Addresses, and then Control-Click to bring up a contextual menu with possible actions for any Internet Addresses in that selection. Actions can include sending an email message or displaying a web page for example.

Since IPNetMonitor handles the 'GURL' Apple Event, it is possible to include IPNetMonitor tools such as ping and traceroute in the list of available actions for an Internet Address by writing appropriate action scripts. Kirk Batty has written a set of action scripts for ping, traceroute, whois, and finger which you can install in the Apple Data Detectors control panel.

Download IAD action scripts for use with IPNetMonitor