Incoming SIP call via SwyxLink using DDI fails (kb3071)

The information in this article applies to:

  • SwyxWare v5.01

[ Symptoms | Cause | Resolution | Status ]


Incoming SIP call via SwyxLink using DDI fails.


In this case the Link Manager is unable to assign an incoming call to a SIP-Link. You need to set a specific registry key to fix this problem (see below). This key consists of your complete phone number (countrycode + areacode + basicnumber) without your direct-inward dialing number. There are three different number formats for this (see below).
Technical Details:
This registry key changes the SIP URI in the "Contact-Header" of the SIP REGISTER. The value of the registry key (your basic number) is set before the @ in the SIP URI. In the case of an incoming call (INVITE), the call can be assigned to a link if the Request-URI is at least the basic number or longer than the basic number.


Before you start please read chapter
"SIP Connection with DDI (Direct Dial In)"
(Page 9-5) in SwyxWare 5.01 manual.

01. Stop the Link Manager service.
02. Start the Windows Registry Editor
03. Open the treeview for HKEY_LOCAL_MACHINE
04. Open the following path:
05. Create a new folder (key) with the name
      of your SIP Link (the name must be same as
      in your SwyxWare).
06. Open the new folder (key).
07. Create a new entry (String) named "SipTrunkNumber"
      in the right window (see picture).

DDI SipTrunkNumber Sample
DDI SipTrunkNumber Sample
Click to enlarge...

08. Now insert your telephone number as value for this entry. Please
     note that you have to choose the correct number format.

     Possible number formats:

      - Canonical with plus (+492314777)
      - Canonical without plus (492314777)
      - National (02314777)

    If you are unsure which format is the right one for your
    case, you should test them in turn.

09. Close the Windows Registry Editor.
10. Start the Link Manager service.

Now all incoming calls for this SIP Link should be transfered correctly.


Workaround available. (see above)


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