ISDN diagnostic codes
The ISDN cause codes help to track down ISDN connection problems. The DEFENDO menu "Monitoring -> Log files" provides the corresponding log file. Consider the 4 or 5 character code at the end of each line.
For german 1TR6 you will get a 4 character code. Euro-ISDN and leased lines provide 5 characters starting with E and L respectively.
The last two characters indicate a specific message. The two preceding characters describes the location which reports it.
The following mappings apply:
- for Euro-ISDN (E-DSS1)
- E00xx: DEFENDO
- E01xx: local PBX or device
- E02xx: public phone network serving the local user
- E03xx: public transit network
- E04xx: public phone network serving the remote user
- E05xx: remote PBX or device
- E07xx: international phone network
- for obsolete german 1TR6
- 44xx: public phone network
- 45xx: private phone network
The following list provides an overview of the most common cause codes and their meaning:
- Exx10, xx00
- This code indicates a successful call clearing. In case of PPP dial-up connections it can occur that the ISDN connection is established successfully but hangs-up after a few seconds. This is usually caused by a failed PPP negotiation. Please refer to article >PPP debug log for PPP diagnostics.
- Exx22, xx08
- No channel available
- An ISDN S0 bus provides a maximum of two B-channels shared by all connected devices. This cause code indicates that all available channels are busy at the moment. Please check which other ISDN devices (e.g. router, fax, phones) are connected to the same S0 bus. Note that multiple network wall sockets may provide the same S0 bus. DEFENDO and all the other devices connected to the bus can operate a maximum of two simultaneous ISDN connections.
- Exx11, xx3B
- The called number is busy
- Exx12, xx3A
- Called number not responding. Please check if the number is correct. If DEFENDO is connected to a PBX it is usually necessary to prefix the called number (usually by a zero). Make sure the remote device is up and running.
- Exx01
- You will get this cause code if you configured an invalid MSN in DEFENDO. Only few PBXs actually verify the MSN of connected devices. If only outgoing calls are required (e.g. when calling an ISP to establish the Internet dial-up connection) you should change the MSN to 0 which is usually accepted by a PBX. For incoming calls however (e.g. dial-in for technical support) setting the correct MSN is crucial. Check the configuration of the PBX to find out which MSN DEFENDO may use.
- Exx58
- The called device is incompatible. You will get this message e.g. if you call a normal telephone which obviously is not able to dial with data connections. Verify if the phone number is correct. If DEFENDO is connected to a PBX you will most likely require a prefix.
- Exx2A
- The PBX is congested.
- Exx1F
- This is a painful message. The PBX indicates a problem but does not provide any further details. Please ask the maintainer
of your PBX to track the problem down. From our experience frequent causes are:
- Data calls are not allowed
- Long distance calls or calls to service numbers are forbidden
- The phone company does not allow data calls. The phone company might even be selected by-call if a least cost router has been installed.
- Exx15, xx3E
- The call was rejected. The peer might be configured to use D-channel callback. It is also possible that the callee verifies the caller ID and drops calls using unknown numbers.
- Exx3F
- Service or option not available. This code is commonly reported if data calls are not allowed. Please check the setup of the local PBX.