SIP 200 OK vs 481 Call/Transaction Does Not Exist
SIP 200 (OK) is a 2xx Success response, while 481 (Call/Transaction Does Not Exist) 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, 481 means that the UAS received a request that does not match any existing dialog or transaction. The call state may have been lost.
Deskripsi
The request has succeeded. For INVITE, the call has been answered. For other methods, the action has been completed successfully.
Ketika Anda Melihatnya
When a call is answered (INVITE 200 OK), a registration succeeds (REGISTER 200 OK), or a subscription is accepted (SUBSCRIBE 200 OK).
Cara Memperbaiki
No fix needed — this is a success response. The caller should send an ACK to complete the three-way handshake for INVITE transactions.
Deskripsi
The UAS received a request that does not match any existing dialog or transaction. The call state may have been lost.
Ketika Anda Melihatnya
When sending a BYE, re-INVITE, or UPDATE for a call that the server has no record of. Common after server restarts.
Cara Memperbaiki
The dialog has been lost. Terminate the local call state. For re-INVITE failures, re-establish the call from scratch.
Perbedaan Utama
200 is a 2xx Success response, while 481 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 481: The UAS received a request that does not match any existing dialog or transaction. The call state may have been lost.
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 481 when when sending a BYE, re-INVITE, or UPDATE for a call that the server has no record of. Common after server restarts.
Kapan Menggunakan Yang Mana
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 481 (Call/Transaction Does Not Exist): The dialog has been lost. Terminate the local call state. For re-INVITE failures, re-establish the call from scratch.