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Connecting to a PABX

Various problems can arise when connecting a Diva card via a local PABX.
It is highly recommended to confirm the correct operation of the Diva card first by using a direct connection from the Diva card to an ISDN line, if available.

Incoming call problems

General configuration issues:

• Make sure there is an application listening for incoming calls (e.g. RAS or fax software)
• Make sure there is only one application listening for incoming calls on a particular MSN

PABX configuration issues: 

• The PABX does not adhere fully to international ISDN standards on its internal lines
• Certain ISDN services are not fully enabled (e.g. enabled only for outgoing and not for incoming calls)
• Problems with the mapping of internal and external MSN's, if used (depends on the PABX)
• Incorrect ISDN protocols configured
• Special protocols are enabled (e.g. QSIG), which require supplementary services (which may not be fully supported by the Telco or need to be specifically ordered)

Outgoing call problems

• A necessary dial-prefix is not being used, or is incorrect (e.g. 0 or 9 is required before the actual number)
• There could be special features (PABX filters) enabled, which prevent making outgoing calls via all, or specific, MSN's. For example, all international phone numbers, or phone numbers with certain area codes.
• Some older PABX firmware / software versions require an upgrade to function correctly

If there are problems with incoming and outgoing calls then there is likely to be a mixture of the issues mentioned above.
For additional help, please also see the Troubleshooting Checklist.