The 6xx codes or global failure codes indicate that the request cannot be fulfilled at any server. They are described in detail in the following table:
|
Code |
Event name |
Reason |
|
600 |
Busy everywhere |
The recipient's end system was contacted successfully, but the user is busy and does not wish to take the call at this moment |
|
603 |
Decline |
The receiving UA was successfully contacted, but the user explicitly does not wish to or cannot participate |
|
604 |
Does not exist anywhere |
The server has authoritative information that the user indicated in the Request URI, which does not exist anywhere |
|
606 |
Not acceptable |
The US was contacted successfully, but some aspects of the session description described by SDP were not acceptable |