SIP 204 No Notification vs 480 Temporarily Unavailable
SIP 204 (No Notification) is a 2xx Success response, while 480 (Temporarily Unavailable) 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, 480 means that the callee's end system was contacted successfully but the callee is currently unavailable. The client may retry after some time.
Beschreibung
The request was successful but the server has decided not to send a NOTIFY for this SUBSCRIBE request.
Wann Sie es sehen
When subscribing to event packages that may not generate immediate notifications, such as dialog or presence packages.
Wie man es behebt
No fix needed. The subscription was accepted but there is no state change to notify about yet.
Beschreibung
The callee's end system was contacted successfully but the callee is currently unavailable. The client may retry after some time.
Wann Sie es sehen
When the user exists but is not currently reachable — phone is off, DND mode enabled, or all lines are busy.
Wie man es behebt
Try calling again later. Check if the callee has DND enabled or if their device is powered off. Configure voicemail for unavailable scenarios.
Wesentliche Unterschiede
204 is a 2xx Success response, while 480 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 480: The callee's end system was contacted successfully but the callee is currently unavailable. The client may retry after some time.
You encounter 204 when when subscribing to event packages that may not generate immediate notifications, such as dialog or presence packages.
You encounter 480 when when the user exists but is not currently reachable — phone is off, DND mode enabled, or all lines are busy.
Wann welchen verwenden
For 204 (No Notification): No fix needed. The subscription was accepted but there is no state change to notify about yet. For 480 (Temporarily Unavailable): Try calling again later. Check if the callee has DND enabled or if their device is powered off. Configure voicemail for unavailable scenarios.