436
SIP
436 Bad Identity-Info
The Identity-Info header contains a URI that the server cannot dereference to obtain the signing certificate.
On this page
When You See This Code
When the Identity-Info URI in the request points to an unreachable or invalid certificate location.
How to Fix
Ensure the Identity-Info URI is reachable and points to a valid certificate. Check DNS resolution and TLS configuration.
Specification
Compare With
Guides
401 Unauthorized vs 403 Forbidden: When to Use Each
Security & Authentication
SIP Response Codes: Understanding VoIP Call Flow
Real-Time Protocols
SIP Call Flow: Understanding Session Setup
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WebRTC Signaling with SIP and WebSocket
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RFC 3261: SIP Protocol Deep Dive
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TLS 1.3: Faster, Simpler, More Secure
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Frequently Asked Questions
What is SIP 436 Bad Identity-Info?
The Identity-Info header contains a URI that the server cannot dereference to obtain the signing certificate.
When do you see SIP 436 Bad Identity-Info?
When the Identity-Info URI in the request points to an unreachable or invalid certificate location.
How to fix SIP 436 Bad Identity-Info?
Ensure the Identity-Info URI is reachable and points to a valid certificate. Check DNS resolution and TLS configuration.