ISDN monitor for Windows

CapiDog is a freeware from Shamrock Software for all 32-bit Windows versions. Note that Shamrock does not offer hotline support for freeware and does not guarantee the function in a specific environment. Copying the program or this documentation to Internet sites other than the Shamrock site or to a CDROM without an explicit permission from Shamrock Software is illegal and violates copyright laws and regulations. Version info:

1.54 31.10.18 IE Display for log file
1.52 14.02.11 Further imprivements of channel indicators
1.51 02.02.11 Corrected busy channel indication
1.49 27.08.08 Controller no. configuration for status display
1.48 29.05.08 Changed window title to "Shamrock CapiDog".

How it works, what it does

CapiDog shows which bearer channels (B channels) are in use on an ISDN S0 line. A task bar symbol shows two colored squares, one for each channel. A popup window displays the numbers of incoming and outgoing calls. If CapiCall is installed on the same PC, even the names corresponding to these numbers are displayed if they are found in the CapiCall phone book. Connections can be logged with time, number and duration. For finding ISDN problems, a D channel trace can be written.

CapiDog requires an ISDN adapter with a special CAPI 2.0 extension. Adapters from AVM (driver release 3.08 and higher), Scitel (autumn 2000 or later) or Gerdes/Primux are suitable. CapiDog will not work after you start another application which monitors the D channel, like AVM IWatch.

An ISDN adapter only can "see" information coming from the public switch or PABX, so CapiDog is somewhat limited in what it can display.

Installation, uninstallation

There is no dedicated "setup" program for CapiDog. Simply extract the file CDOGENGL.ZIP into a new empty folder like C:\Shamrock\Capidog using WinZip or a similar unzip program and then create an entry in the Startup folder (Windows Start - Programs - Startup; see Windows Help how to do this):


Important: Do not install CapiDog below C:\Program Files!

When CapiDog is launched, an icon with two (initially green) squares will appear in the Windows system tray. The colors of these squares show the status of the two ISDN channels:

  in use

If you click on this symbol with the primary mouse button, the CapiDog Window appears (or disappears) showing the calling and called number if available (see FAQ). The menu language is English, if the file ENGLISH.CD is present. If you install the CapiCall voice mailbox software, the CapiDog menu language will depend on the CapiCall language setting. The symbols in CapiDog have these functions:

These functions are also available in the CapiDog menu. This also contains a Reset option which deletes a trace file (if present) and resets all channels to their "green" state after possible d-channel synchronization problems.

In addition, you will get a context menu when clicking on the CapiDog system tray symbol using the secondary mouse button.

To deinstall CapiDog later, simply delete the CapiDog folder and use a text editor to delete the [CapiDog] part of WIN.INI in the windows directory.

Options of CapiDog

There is a trace option in the CapiDog main window which can be used for in-depth ISDN analysis:

Other options are available via "Configuration" in the "File" menu:

The list Show warnings for contains a list of expensive premium-rate numbers, and Show no warnings can be used to define exceptions. For instance, if you enter 0191 for "show warnings", you might enter the T-Online number 01910 as an exception in "show no warnings".

In the optional log file, the service code is stored numerically only. Typical values are:

ISDN service codes in CAPI 2.0
1 Speech
2 Data/standard
3 Data/restricted
4 Speech 3.1 kHz
5 Speech 7 kHz
6 Video
7 Packet Mode
8 Adapt. 56 kBit/s
9 Data+messages
16 Digital speech
17 Fax G2/3
18 Fax G4-I
19 Fax G4-II/III
20,21,23 Telex
22 Videotex
24 X.400/E-Mail
25 X.200/OSI Layer
26 Speech 7 kHz
27 Video phone L1
28 Video phone L2

Questions and answers

Why is CapiDog only suitable for AVM, Scitel and Primux/Gerdes ISDN adapters?

CapiDog uses undocumented, manufacturer-specific extensions of the CAPI 2.0 driver to log D-channel information. Please note that Shamrock will not answer questions about these undocumented extensions.

Why can't I delete 0900 from the blacklist?

Instead of doing this, you may add specific 0900 numbers to the whitelist, like 090012345, and thus avoid an alarm when they are dialled.

Sometimes the destination number is not displayed for outgoing calls - why?

For outgoing calls, the destination number can only be detected if the public switch reflects it as "called number" since the ISDN adapter cannot see the data sent by an ISDN telephone even if it is connected to the same bus.

Sometimes the MSN and service code of outgoing calls are not displayed - why?

If the call is not initiated by the ISDN adapter itself, but by an ISDN telephone, for instance, CapiDog cannot see this information.

Sometimes one channel stays red even if there is no connection. Why?

CapiDog can only listen passively on the ISDN bus and cannot request retries of lost data packets. When errors occur on the ISDN bus, or a connection breaks without disconnecting properly, CapiDog will be unable to detect the end of a connection. In this case, simply select the Reset option in the CapiDog menu.

What means something like 1234 < 5678 in the MSN field?

If there is a second number in the MSN field this means that a call has been redirected; in the above case, the caller originally called 5678, but the call was deflected to 1234. Please note that not all switches and PBX systems support this function.

Nothing is displayed if I am using an analogue telephone. Why?

If you connect CapiDog to an internal ISDN outlet of a PBX, it will "see" only things that happen on that internal bus. If an analogue phone is used to call an external number, the internal ISDN bus is not involved. To avoid this problem, you may connect the ISDN adapter to the external ISDN bus instead.

Sometimes the caller's number seems to be incomplete.

This is a bug in the AVM CAPI 2.0 driver releases up to 3.07xx. You will see the release number in the status bar at the bottom of the CapiDog window. If the number is below 3.08, update your driver from the AVM web site.

Useful links

If you have questions or suggestions, please go to and write us a message. This is also where you might find an updated version of this software. Here are some more links with useful information about ISDN: ETSI documents (e.g. Q.921, Q.931) Information about the CAPI standard ISDN voice mailbox, fax server

Shamrock Software GmbH