SIP 204 No Notification vs 502 Bad Gateway
SIP 204 (No Notification) is a 2xx Success response, while 502 (Bad Gateway) is a 5xx Server 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, 502 means that the server, acting as a gateway or proxy, received an invalid response from a downstream server it accessed in attempting to fulfill the request.
คำอธิบาย
The request was successful but the server has decided not to send a NOTIFY for this SUBSCRIBE request.
เมื่อคุณพบเห็น
When subscribing to event packages that may not generate immediate notifications, such as dialog or presence packages.
วิธีแก้ไข
No fix needed. The subscription was accepted but there is no state change to notify about yet.
คำอธิบาย
The server, acting as a gateway or proxy, received an invalid response from a downstream server it accessed in attempting to fulfill the request.
เมื่อคุณพบเห็น
When a SIP proxy receives a malformed or invalid response from the next-hop server. Common in interop scenarios between different vendors.
วิธีแก้ไข
Check the downstream server's health and configuration. Verify SIP message formatting between the two servers. Review network connectivity.
ความแตกต่างหลัก
204 is a 2xx Success response, while 502 is a 5xx Server Failure response.
SIP 204: The request was successful but the server has decided not to send a NOTIFY for this SUBSCRIBE request.
SIP 502: The server, acting as a gateway or proxy, received an invalid response from a downstream server it accessed in attempting to fulfill the request.
You encounter 204 when when subscribing to event packages that may not generate immediate notifications, such as dialog or presence packages.
You encounter 502 when when a SIP proxy receives a malformed or invalid response from the next-hop server. Common in interop scenarios between different vendors.
ควรใช้อันไหนเมื่อไร
For 204 (No Notification): No fix needed. The subscription was accepted but there is no state change to notify about yet. For 502 (Bad Gateway): Check the downstream server's health and configuration. Verify SIP message formatting between the two servers. Review network connectivity.