SIP 181 Call Is Being Forwarded vs 580 Precondition Failure
SIP 181 (Call Is Being Forwarded) is a 1xx Provisional response, while 580 (Precondition Failure) is a 5xx Server Failure response. 181 indicates that a proxy server may send this to indicate that the call is being forwarded to a different set of destinations. In contrast, 580 means that the server is unable or unwilling to meet some of the preconditions specified in the request for resource reservation.
Description
A proxy server may send this to indicate that the call is being forwarded to a different set of destinations.
When You See It
When the callee has call forwarding enabled and the request is being redirected to another number or device.
How to Fix
No action needed. The call is being redirected. If forwarding is unintended, the callee should update their forwarding settings.
Description
The server is unable or unwilling to meet some of the preconditions specified in the request for resource reservation.
When You See It
When using QoS preconditions (RFC 3312) and the network cannot guarantee the required quality of service for the media session.
How to Fix
Relax the precondition requirements or ensure the network path supports the required QoS. Consider removing precondition requirements for best-effort calls.
Key Differences
181 is a 1xx Provisional response, while 580 is a 5xx Server Failure response.
SIP 181: A proxy server may send this to indicate that the call is being forwarded to a different set of destinations.
SIP 580: The server is unable or unwilling to meet some of the preconditions specified in the request for resource reservation.
You encounter 181 when when the callee has call forwarding enabled and the request is being redirected to another number or device.
You encounter 580 when when using QoS preconditions (RFC 3312) and the network cannot guarantee the required quality of service for the media session.
When to Use Which
For 181 (Call Is Being Forwarded): No action needed. The call is being redirected. If forwarding is unintended, the callee should update their forwarding settings. For 580 (Precondition Failure): Relax the precondition requirements or ensure the network path supports the required QoS. Consider removing precondition requirements for best-effort calls.