423
SIP
423 Interval Too Brief
The expiration time in the request is too short. The response contains a Min-Expires header indicating the minimum allowed value.
On this page
When You See This Code
When a REGISTER or SUBSCRIBE request has an Expires value that is below the server's minimum. Common with aggressive keep-alive timers.
How to Fix
Increase the Expires header value to at least the Min-Expires value from the response.
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
Real-Time Protocols
WebRTC Signaling with SIP and WebSocket
Real-Time Protocols
RFC 3261: SIP Protocol Deep Dive
Protocol Deep Dives
TLS 1.3: Faster, Simpler, More Secure
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Frequently Asked Questions
What is SIP 423 Interval Too Brief?
The expiration time in the request is too short. The response contains a Min-Expires header indicating the minimum allowed value.
When do you see SIP 423 Interval Too Brief?
When a REGISTER or SUBSCRIBE request has an Expires value that is below the server's minimum. Common with aggressive keep-alive timers.
How to fix SIP 423 Interval Too Brief?
Increase the Expires header value to at least the Min-Expires value from the response.