SIP 100 Trying vs 500 Server Internal Error
SIP 100 (Trying) is a 1xx Provisional response, while 500 (Server Internal Error) is a 5xx Server Failure response. 100 indicates that the request has been received by the next-hop server and an unspecified action is being taken to process it. The UAC should expect additional responses. In contrast, 500 means that the server encountered an unexpected condition that prevented it from fulfilling the request.
Descripción
The request has been received by the next-hop server and an unspecified action is being taken to process it. The UAC should expect additional responses.
Cuándo lo verás
Immediately after sending an INVITE. The proxy has received the call and is searching for the callee. This is the SIP equivalent of a dial tone.
Cómo solucionarlo
No fix needed — this is normal call setup behavior. If stuck on 100 Trying for too long, check network connectivity and proxy configuration.
Descripción
The server encountered an unexpected condition that prevented it from fulfilling the request.
Cuándo lo verás
When the SIP server has an internal error — database failure, unhandled exception, or resource exhaustion.
Cómo solucionarlo
Check server logs for the specific error. Common causes include database connectivity issues, configuration errors, or memory exhaustion.
Diferencias clave
100 is a 1xx Provisional response, while 500 is a 5xx Server Failure response.
SIP 100: The request has been received by the next-hop server and an unspecified action is being taken to process it. The UAC should expect additional responses.
SIP 500: The server encountered an unexpected condition that prevented it from fulfilling the request.
You encounter 100 when immediately after sending an INVITE. The proxy has received the call and is searching for the callee. This is the SIP equivalent of a dial tone.
You encounter 500 when when the SIP server has an internal error — database failure, unhandled exception, or resource exhaustion.
Cuándo usar cada uno
For 100 (Trying): No fix needed — this is normal call setup behavior. If stuck on 100 Trying for too long, check network connectivity and proxy configuration. For 500 (Server Internal Error): Check server logs for the specific error. Common causes include database connectivity issues, configuration errors, or memory exhaustion.