SIP 300 Multiple Choices vs 505 Version Not Supported
SIP 300 (Multiple Choices) is a 3xx Redirection response, while 505 (Version Not Supported) is a 5xx Server 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, 505 means that the server does not support the SIP protocol version that was used in the request. Currently only SIP/2.0 is standardized.
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 server does not support the SIP protocol version that was used in the request. Currently only SIP/2.0 is standardized.
When You See It
Extremely rare. Would occur if a client sends a request with a SIP version other than 2.0.
How to Fix
Ensure your UA uses SIP/2.0 in the request line. This is the only standardized version.
Key Differences
300 is a 3xx Redirection response, while 505 is a 5xx Server 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 505: The server does not support the SIP protocol version that was used in the request. Currently only SIP/2.0 is standardized.
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 505 when extremely rare. Would occur if a client sends a request with a SIP version other than 2.0.
When to Use Which
For 300 (Multiple Choices): Select one of the provided Contact addresses and resend the request to that specific URI. For 505 (Version Not Supported): Ensure your UA uses SIP/2.0 in the request line. This is the only standardized version.