SIP 300 Multiple Choices vs 404 Not Found
SIP 300 (Multiple Choices) is a 3xx Redirection response, while 404 (Not Found) 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, 404 means that the user specified in the Request-URI does not exist at the domain. The server has authoritative information that the user does not exist.
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 user specified in the Request-URI does not exist at the domain. The server has authoritative information that the user does not exist.
When You See It
When calling a number or SIP address that does not exist on the server. Different from 480 (user exists but is temporarily unavailable).
How to Fix
Verify the SIP URI or phone number. Check if the user is registered on the correct domain. Ensure the domain is correct.
Key Differences
300 is a 3xx Redirection response, while 404 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 404: The user specified in the Request-URI does not exist at the domain. The server has authoritative information that the user does not exist.
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 404 when when calling a number or SIP address that does not exist on the server. Different from 480 (user exists but is temporarily unavailable).
When to Use Which
For 300 (Multiple Choices): Select one of the provided Contact addresses and resend the request to that specific URI. For 404 (Not Found): Verify the SIP URI or phone number. Check if the user is registered on the correct domain. Ensure the domain is correct.