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ProtocolCodes
480
SIP

480 Temporarily Unavailable

The callee's end system was contacted successfully but the callee is currently unavailable. The client may retry after some time.

On this page

When You See This Code

When the user exists but is not currently reachable — phone is off, DND mode enabled, or all lines are busy.

How to Fix

Try calling again later. Check if the callee has DND enabled or if their device is powered off. Configure voicemail for unavailable scenarios.

Specification

View RFC / Specification →

Comparisons

SIP 480 Temporarily Unavailable vs 486 Busy Here

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

408 Request Timeout in NAT Traversal Advanced
503 Service Unavailable — SIP Trunk Overloaded Intermediate
486 Busy Here — Call Routing Loop Misdiagnosis Intermediate

Specifications

RFC 3261 SIP: Session Initiation Protocol
RFC 3265 Session Initiation Protocol (SIP)-Specific Event Notification
RFC 6665 SIP-Specific Event Notification

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 480 Temporarily Unavailable?

The callee's end system was contacted successfully but the callee is currently unavailable. The client may retry after some time.

When do you see SIP 480 Temporarily Unavailable?

When the user exists but is not currently reachable — phone is off, DND mode enabled, or all lines are busy.

How to fix SIP 480 Temporarily Unavailable?

Try calling again later. Check if the callee has DND enabled or if their device is powered off. Configure voicemail for unavailable scenarios.