SIP 200 OK vs 489 Bad Event
SIP 200 (OK) is a 2xx Success response, while 489 (Bad Event) is a 4xx Client Failure response. 200 indicates that the request has succeeded. For INVITE, the call has been answered. For other methods, the action has been completed successfully. In contrast, 489 means that the server did not understand the event package specified in the Event header of a SUBSCRIBE request.
Description
The request has succeeded. For INVITE, the call has been answered. For other methods, the action has been completed successfully.
When You See It
When a call is answered (INVITE 200 OK), a registration succeeds (REGISTER 200 OK), or a subscription is accepted (SUBSCRIBE 200 OK).
How to Fix
No fix needed — this is a success response. The caller should send an ACK to complete the three-way handshake for INVITE transactions.
Description
The server did not understand the event package specified in the Event header of a SUBSCRIBE request.
When You See It
When subscribing to an event package that the server does not support (e.g., dialog, presence, message-summary).
How to Fix
Check which event packages the server supports (OPTIONS request) and use a supported event package name.
Key Differences
200 is a 2xx Success response, while 489 is a 4xx Client Failure response.
SIP 200: The request has succeeded. For INVITE, the call has been answered. For other methods, the action has been completed successfully.
SIP 489: The server did not understand the event package specified in the Event header of a SUBSCRIBE request.
You encounter 200 when when a call is answered (INVITE 200 OK), a registration succeeds (REGISTER 200 OK), or a subscription is accepted (SUBSCRIBE 200 OK).
You encounter 489 when when subscribing to an event package that the server does not support (e.g., dialog, presence, message-summary).
When to Use Which
For 200 (OK): No fix needed — this is a success response. The caller should send an ACK to complete the three-way handshake for INVITE transactions. For 489 (Bad Event): Check which event packages the server supports (OPTIONS request) and use a supported event package name.