SIP 204 No Notification vs 416 Unsupported URI Scheme
SIP 204 (No Notification) is a 2xx Success response, while 416 (Unsupported URI Scheme) is a 4xx Client Failure response. 204 indicates that the request was successful but the server has decided not to send a NOTIFY for this SUBSCRIBE request. In contrast, 416 means that the server cannot process the request because the URI scheme in the Request-URI is unknown to the server.
説明
The request was successful but the server has decided not to send a NOTIFY for this SUBSCRIBE request.
このコードが表示される場合
When subscribing to event packages that may not generate immediate notifications, such as dialog or presence packages.
解決方法
No fix needed. The subscription was accepted but there is no state change to notify about yet.
説明
The server cannot process the request because the URI scheme in the Request-URI is unknown to the server.
このコードが表示される場合
When using a URI scheme (e.g., tel:, im:, pres:) that the receiving server does not support.
解決方法
Use a supported URI scheme. Most SIP servers support sip: and sips: schemes. Check server capabilities with OPTIONS.
主な違い
204 is a 2xx Success response, while 416 is a 4xx Client Failure response.
SIP 204: The request was successful but the server has decided not to send a NOTIFY for this SUBSCRIBE request.
SIP 416: The server cannot process the request because the URI scheme in the Request-URI is unknown to the server.
You encounter 204 when when subscribing to event packages that may not generate immediate notifications, such as dialog or presence packages.
You encounter 416 when when using a URI scheme (e.g., tel:, im:, pres:) that the receiving server does not support.
どちらをいつ使うか
For 204 (No Notification): No fix needed. The subscription was accepted but there is no state change to notify about yet. For 416 (Unsupported URI Scheme): Use a supported URI scheme. Most SIP servers support sip: and sips: schemes. Check server capabilities with OPTIONS.