SIP 486 Busy Here
Short definition
SIP 486 Busy Here is a SIP response indicating that the particular called endpoint or user is busy and cannot take the call.
Meaning and how it works
An endpoint may return 486 in response to an INVITE when it is occupied. Other contacts or alternative routes may still be available. The PBX can apply a preconfigured fallback, such as a queue, another agent or voicemail.
Business applications
- Business scenario:
An agent is already speaking to a customer, so the next incoming call is routed to a colleague rather than being dropped.
What to check before implementation
Distinguish busy status from rejection, failed registration and network faults. The actual fallback depends on the call-routing policy.