SIP 199 Early Dialog Terminated vs 433 Anonymity Disallowed
SIP 199 (Early Dialog Terminated) is a 1xx Provisional response, while 433 (Anonymity Disallowed) is a 4xx Client Failure response. 199 indicates that a UAS can send this to indicate that an early dialog has been terminated. Used when forking results in multiple early dialogs. In contrast, 433 means that the request has been rejected because the server policy requires caller identification and the request was anonymous.
Description
A UAS can send this to indicate that an early dialog has been terminated. Used when forking results in multiple early dialogs.
When You See It
In forked call scenarios when one of the forked branches is cancelled because another branch was answered.
How to Fix
No action needed. This is normal behavior in forked call setups. Ensure your UA handles early dialog termination gracefully.
Description
The request has been rejected because the server policy requires caller identification and the request was anonymous.
When You See It
When calling with caller ID suppressed (anonymous) to a server or destination that requires caller identification.
How to Fix
Remove the Privacy header or include proper caller identification. Some networks require valid From header identity.
Key Differences
199 is a 1xx Provisional response, while 433 is a 4xx Client Failure response.
SIP 199: A UAS can send this to indicate that an early dialog has been terminated. Used when forking results in multiple early dialogs.
SIP 433: The request has been rejected because the server policy requires caller identification and the request was anonymous.
You encounter 199 when in forked call scenarios when one of the forked branches is cancelled because another branch was answered.
You encounter 433 when when calling with caller ID suppressed (anonymous) to a server or destination that requires caller identification.
When to Use Which
For 199 (Early Dialog Terminated): No action needed. This is normal behavior in forked call setups. Ensure your UA handles early dialog termination gracefully. For 433 (Anonymity Disallowed): Remove the Privacy header or include proper caller identification. Some networks require valid From header identity.