SIP 202 Accepted vs 420 Bad Extension
SIP 202 (Accepted) is a 2xx Success response, while 420 (Bad Extension) 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, 420 means that the server did not understand the protocol extension specified in a Require or Proxy-Require header. The Unsupported header lists the unknown extensions.
Описание
The request has been accepted for processing but the processing has not been completed. Used primarily for REFER requests.
Когда вы это видите
After sending a REFER request for call transfer. The transfer target acknowledges receipt but hasn't completed the transfer yet.
Как исправить
Wait for a NOTIFY to learn the outcome of the referred action. If no NOTIFY arrives, check subscription state and network connectivity.
Описание
The server did not understand the protocol extension specified in a Require or Proxy-Require header. The Unsupported header lists the unknown extensions.
Когда вы это видите
When the request includes a Require header with SIP extensions that the server does not support.
Как исправить
Check the Unsupported header in the response. Remove the unsupported extension from the Require header or make it optional via Supported.
Ключевые различия
202 is a 2xx Success response, while 420 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 420: The server did not understand the protocol extension specified in a Require or Proxy-Require header. The Unsupported header lists the unknown extensions.
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 420 when when the request includes a Require header with SIP extensions that the server does not support.
Когда что использовать
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 420 (Bad Extension): Check the Unsupported header in the response. Remove the unsupported extension from the Require header or make it optional via Supported.