SIP 200 OK vs 480 Temporarily Unavailable
SIP 200 (OK) is a 2xx Success response, while 480 (Temporarily Unavailable) 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, 480 means that the callee's end system was contacted successfully but the callee is currently unavailable. The client may retry after some time.
描述
The request has succeeded. For INVITE, the call has been answered. For other methods, the action has been completed successfully.
何时出现
When a call is answered (INVITE 200 OK), a registration succeeds (REGISTER 200 OK), or a subscription is accepted (SUBSCRIBE 200 OK).
如何修复
No fix needed — this is a success response. The caller should send an ACK to complete the three-way handshake for INVITE transactions.
描述
The callee's end system was contacted successfully but the callee is currently unavailable. The client may retry after some time.
何时出现
When the user exists but is not currently reachable — phone is off, DND mode enabled, or all lines are busy.
如何修复
Try calling again later. Check if the callee has DND enabled or if their device is powered off. Configure voicemail for unavailable scenarios.
主要区别
200 is a 2xx Success response, while 480 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 480: The callee's end system was contacted successfully but the callee is currently unavailable. The client may retry after some time.
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 480 when when the user exists but is not currently reachable — phone is off, DND mode enabled, or all lines are busy.
何时使用哪个
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 480 (Temporarily Unavailable): Try calling again later. Check if the callee has DND enabled or if their device is powered off. Configure voicemail for unavailable scenarios.