M4 Disconnect Codes

M4 Disconnect Codes is a rework of M2 Hangupcause Codes to support a new structure with the idea to move away from ISDB Q.850 codes to the SIP codes.

The rework is done in steps and for some time old HGC codes still are used in the system.

DC Groups

System supports different groups of codes:

• Default - default values for the codes used in case it is necessary to reset back from custom changes from the Global group. Values in the Default group can't be changed in any way
• Global - a global group used for the values which are not set in the Custom Groups. Values in the Global group can be freely changed. Save CDR property can only be changed in the Global group.
• Custom Groups

Namespace

Disconnect Codes are separated into Namespaces:

• Q.850 - ISDN Q.850 Codes currently used as main codes in the system
• SIP - SIP Codes 3XX-6XX
• CORE - Unique Core related codes in the format 8XX

Codes

Each code has several properties:

• Code - actual code
• Reason - description of the code
• Changed Code/Reason - SIP code/reason to be used in case if the change is necessary (covers Q.850->SIP mapping also)
• Q.850 - Q.850 Code change. Only applicable to the SIP Codes for SIP->Q.850 mapping
• Reroute - property to tell the system if a call should be rerouted for some code
• Reason Header - possible actions with the Reason Header
• Save CDR - should we save CDR for this code. Can only be changed in the Global group.