SIP 200 OK vs 502 Bad Gateway
SIP 200 (OK) is a 2xx Success response, while 502 (Bad Gateway) is a 5xx Server 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, 502 means that the server, acting as a gateway or proxy, received an invalid response from a downstream server it accessed in attempting to fulfill the request.
Description
The request has succeeded. For INVITE, the call has been answered. For other methods, the action has been completed successfully.
Quand vous le voyez
When a call is answered (INVITE 200 OK), a registration succeeds (REGISTER 200 OK), or a subscription is accepted (SUBSCRIBE 200 OK).
Comment résoudre
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, acting as a gateway or proxy, received an invalid response from a downstream server it accessed in attempting to fulfill the request.
Quand vous le voyez
When a SIP proxy receives a malformed or invalid response from the next-hop server. Common in interop scenarios between different vendors.
Comment résoudre
Check the downstream server's health and configuration. Verify SIP message formatting between the two servers. Review network connectivity.
Différences clés
200 is a 2xx Success response, while 502 is a 5xx Server 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 502: The server, acting as a gateway or proxy, received an invalid response from a downstream server it accessed in attempting to fulfill the 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 502 when when a SIP proxy receives a malformed or invalid response from the next-hop server. Common in interop scenarios between different vendors.
Quand utiliser lequel
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 502 (Bad Gateway): Check the downstream server's health and configuration. Verify SIP message formatting between the two servers. Review network connectivity.