Locate the response family
- 1xx ProvisionalRequest is progressing
- 2xx SuccessRequest succeeded
- 3xx RedirectionAnother destination
- 4xx Request failureInterpret this request403 belongs here
- 5xx Server failureServer could not fulfil
- 6xx Global failureFailure across destinations
Read the status with its request method and call leg. For example, 200 after REGISTER confirms a binding; it does not prove an INVITE succeeded.
What this response means
The recipient understood the request but refuses it. This is a policy or authorization rejection; it does not universally mean the password is incorrect.
Read it in context
Carrier restrictions, unauthorized caller identity, blocked destinations, account state or PBX access policy can produce a refusal. Implementations may use this response in different operational situations.
Administrator checks
Identify the sender and the rejected method. Compare an allowed destination and another authorized extension. Review route permissions, source identity and carrier account status. Keep the timestamp and call identifier for the party issuing the rejection.
Next action and common mistake
Do not repeatedly retry an unchanged forbidden request or open unrestricted calling to make it pass. Correct the specific authorization issue, then verify both an allowed and a prohibited case. Registration and call permission remain separate checks.
Sources & applicability
Primary references for the technical details above. Operational examples and planning checklists are VoIP.info editorial guidance.