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ProtocolCodes
482
SIP

482 Loop Detected

The server has detected a loop. The request was received with its own address in the Via header, indicating it has been forwarded back to itself.

On this page

When You See This Code

When routing configuration causes a request to cycle between two or more proxies without reaching the callee.

How to Fix

Review proxy routing tables and DNS records. Check for circular references in SIP routing. Fix the routing configuration to break the loop.

Specification

View RFC / Specification →

Compare With

100 Trying 180 Ringing 181 Call Is Being Forwarded 182 Queued 183 Session Progress 199 Early Dialog Terminated 200 OK 202 Accepted 204 No Notification 300 Multiple Choices 301 Moved Permanently 302 Moved Temporarily

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 Protocol Deep Dives

Debugging Scenarios

486 Busy Here — Call Routing Loop Misdiagnosis Intermediate

Glossary

Status Code Request Method (HTTP Verb) TLS Handshake Authentication TCP/IP Port Number NAT (Network Address Translation) Socket Request-Response Model RFC (Request for Comments) Connection-Oriented Full-Duplex SRV Record SIP Dialog Signaling SIP Registrar STUN (Session Traversal Utilities for NAT) TURN (Traversal Using Relays around NAT) SDP (Session Description Protocol) SIP INVITE SIP Proxy Server SIP Redirect Server SIP Transaction SIP User Agent SIP Trunk RTP (Real-time Transport Protocol) SRTP (Secure Real-time Transport Protocol) SIP ACK SIP BYE SIP CANCEL SIP OPTIONS SIP SUBSCRIBE/NOTIFY B2BUA (Back-to-Back User Agent) SBC (Session Border Controller) Codec Negotiation SIP Response Classes VoIP (Voice over IP) Presence (SIP) PBX (Private Branch Exchange) MFA (Multi-Factor Authentication) TLS Versions

Frequently Asked Questions

What is SIP 482 Loop Detected?

The server has detected a loop. The request was received with its own address in the Via header, indicating it has been forwarded back to itself.

When do you see SIP 482 Loop Detected?

When routing configuration causes a request to cycle between two or more proxies without reaching the callee.

How to fix SIP 482 Loop Detected?

Review proxy routing tables and DNS records. Check for circular references in SIP routing. Fix the routing configuration to break the loop.