SIP 202 Accepted vs 422 Session Interval Too Small
SIP 202 (Accepted) is a 2xx Success response, while 422 (Session Interval Too Small) is a 4xx Client Failure response. 202 indicates that the request has been accepted for processing but the processing has not been completed. Used primarily for REFER requests. In contrast, 422 means that the request's Session-Expires value is too small. The Min-SE header in the response indicates the minimum acceptable session interval.
Descrição
The request has been accepted for processing but the processing has not been completed. Used primarily for REFER requests.
Quando você o vê
After sending a REFER request for call transfer. The transfer target acknowledges receipt but hasn't completed the transfer yet.
Como corrigir
Wait for a NOTIFY to learn the outcome of the referred action. If no NOTIFY arrives, check subscription state and network connectivity.
Descrição
The request's Session-Expires value is too small. The Min-SE header in the response indicates the minimum acceptable session interval.
Quando você o vê
When using SIP session timers (RFC 4028) and the proposed session refresh interval is below the server's minimum.
Como corrigir
Increase the Session-Expires value to at least the value indicated in the Min-SE header of the 422 response.
Diferenças principais
202 is a 2xx Success response, while 422 is a 4xx Client Failure response.
SIP 202: The request has been accepted for processing but the processing has not been completed. Used primarily for REFER requests.
SIP 422: The request's Session-Expires value is too small. The Min-SE header in the response indicates the minimum acceptable session interval.
You encounter 202 when after sending a REFER request for call transfer. The transfer target acknowledges receipt but hasn't completed the transfer yet.
You encounter 422 when when using SIP session timers (RFC 4028) and the proposed session refresh interval is below the server's minimum.
Quando usar qual
For 202 (Accepted): Wait for a NOTIFY to learn the outcome of the referred action. If no NOTIFY arrives, check subscription state and network connectivity. For 422 (Session Interval Too Small): Increase the Session-Expires value to at least the value indicated in the Min-SE header of the 422 response.