Fail to Call an IMS User Through the SIP Trunk

When calling the IMS user, the intra-office user hears the busy tone.

The possible causes are as follows:

• The registration group configuration is incorrect.
• The calling number format does not meet IMS (86+area code+number) requirements.
• The registration group ID is not set.

1. See Logging In to the unified gateway Using the LMT.
2. Run the show reggroup command to check whether the status of registration group (the value of Status field).

   Register group 
   
   
   ------ -------------------------------- -------------------------------- ----------- ------------- --------- 
     Id     IMPI                             IMPU                             Password   Expires(*s)   Status   
   ------ -------------------------------- -------------------------------- ----------- ------------- --------- 
   1      +862083785000@guangdong.example.com +862083785000@guangdong.example.com ****        300            FAULT      
   2      +862083785001@guangdong.example.com +862083785001@guangdong.example.com ****        300            FAULT      
   
   
   
   ====  Command executed success !  ====

   • If the status is FAULT, check whether the IMPI field, IMPU field and Password field match the configuration of IMS.

     If no, run the config add reggroup id id impi impi impu impu password password command to modify match the IMS. The id is start number of the registration group. The impi is start registration group IMPI. The impu is start registration group IMPU. The password is password for authentication.

   • If the status is OK, go to the next step.

3. See 2 check whether the calling number change configuration of the prefix meets IMS requirements.
4. Run the show subscriber command to check whether the registration group ID (that is, RegGroupId) corresponding to the user is set. The registration group ID is set, as shown in Figure 1.
   • If no, run the config modify subscriber dn dn reggroupid reggroupid command to change the value of the registration group ID.
   • If yes, go to the next step.
   Figure 1 User registration group 
   
   

5. If the fault still persists, collect detailed fault information and related logs by referring to Collecting and Reporting Fault Information and send them to the service provider.