How to test ISDN lines without having to use the interviewing application or, more generally, how to localize whether a problem is in the interviewing application, the dialer or the ISDN provider

Technote (FAQ)


How to test ISDN lines without having to use the interviewing application or, more generally, how to localize whether a problem is in:
-the application,
-the Dialer, or
-the ISDN provider.
such that you know whom to escalate the problem to.


"Dcontrol.exe" is the tool for making a simple call made via the lines plugged into the dialler.

However, "dcontrol.exe" requires that the master extension is connected such that you can listen to the call. Therefore you need to connect the master extension first with "remote.exe":
remote sip: dcontrol
The SIP call might fail if there is something wrong in the VoIP configuration
or in the LAN connectivity. In this case, or if your dialer is not VoIP enabled, try via ISDN::
remote 0894630750 dcontrol

If this also fails, the error message will hint whether the problem is with the Dialer or the ISDN provider:
remote: Cannot dial "0894630750": Network congestion
The "cause" field in "call.log" contains the more detailed diagnostic from the provider. For the interpretation, see the "\dialer\causes.cfg" entries that start with "0c". For example, cause=34 would map to "No channel available":
0c34 congested No channel available

If the ISDN lines are down altogether ("remote" returns "Trunk down"), the "dialer.log" contains more information:

07/21 10:04:13.84 ERROR 1260/0544 td_cg(370) ISDN 300 Layer 1 yellow alarm (Remote Alarm Indication) (uptime 6d23h11m)
07/21 10:04:13.89 INFO 1260/0544 td_cg(378) ISDN 300 Layer 1 now OK, Layer 2 down (uptime 6d23h11m)
07/21 10:04:15.64 INFO 1260/0544 td_cg_tr(3208) ISDN 300 Layer 2 now OK

Dialing is suspended when Layer 2 is down, or when Layer 1 has an alarm condition. The alarm conditions mean:
-red: the dialer doesn't receive signal from the network terminator (e.g., cable unplugged)
-yellow: the network terminator doesn't receive any signal from dialer (e.g., cable broken)
-blue: the network terminator has lost its upstream connection
-sending RAI: incomprehensible signal received (e.g., wrong cable plugged)
The alarm conditions also occur transiently, for instance, during fail-over in the provider's network.

How to use "dcontrol.exe"

Type In order to
d dial a number (call leg "to the respondent")
D hangup the call
r record the call (both sides of the conversation)
s stop recording or playback
p play the recording back
q quit the program

If there are problems with the audio quality, and you want to determine whether the problem occurs on the interviewer's call leg (SIP or ISDN), use these commands instead of dialing the call leg "to the respondent":

Type In order to
R record message (from "interviewer" only)
s stop recording or playback
P play the recorded message back

Historical Number


Document information

More support for:

SPSS Data Collection Heritage
Quancept CATI

Software version:

Not Applicable

Operating system(s):

Linux, Windows

Reference #:


Modified date:


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