SIP 300 Multiple Choices vs 433 Anonymity Disallowed
SIP 300 (Multiple Choices) is a 3xx Redirection response, while 433 (Anonymity Disallowed) is a 4xx Client Failure response. 300 indicates that the address in the request resolved to several choices, each with its own location. The user or UA can select a preferred communication endpoint. In contrast, 433 means that the request has been rejected because the server policy requires caller identification and the request was anonymous.
Description
The address in the request resolved to several choices, each with its own location. The user or UA can select a preferred communication endpoint.
When You See It
When a user has multiple registered devices or contact addresses and the server cannot determine which one to use.
How to Fix
Select one of the provided Contact addresses and resend the request to that specific URI.
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
300 is a 3xx Redirection response, while 433 is a 4xx Client Failure response.
SIP 300: The address in the request resolved to several choices, each with its own location. The user or UA can select a preferred communication endpoint.
SIP 433: The request has been rejected because the server policy requires caller identification and the request was anonymous.
You encounter 300 when when a user has multiple registered devices or contact addresses and the server cannot determine which one to use.
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 300 (Multiple Choices): Select one of the provided Contact addresses and resend the request to that specific URI. For 433 (Anonymity Disallowed): Remove the Privacy header or include proper caller identification. Some networks require valid From header identity.