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.
説明
The request has been accepted for processing but the processing has not been completed. Used primarily for REFER requests.
このコードが表示される場合
After sending a REFER request for call transfer. The transfer target acknowledges receipt but hasn't completed the transfer yet.
解決方法
Wait for a NOTIFY to learn the outcome of the referred action. If no NOTIFY arrives, check subscription state and network connectivity.
説明
The server did not understand the protocol extension specified in a Require or Proxy-Require header. The Unsupported header lists the unknown extensions.
このコードが表示される場合
When the request includes a Require header with SIP extensions that the server does not support.
解決方法
Check the Unsupported header in the response. Remove the unsupported extension from the Require header or make it optional via Supported.
主な違い
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.
どちらをいつ使うか
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.