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ProtocolCodes
200
SIP

200 OK

The request has succeeded. For INVITE, the call has been answered. For other methods, the action has been completed successfully.

On this page

When You See This Code

When a call is answered (INVITE 200 OK), a registration succeeds (REGISTER 200 OK), or a subscription is accepted (SUBSCRIBE 200 OK).

How to Fix

No fix needed — this is a success response. The caller should send an ACK to complete the three-way handshake for INVITE transactions.

Specification

View RFC / Specification →

Cross-Protocol Equivalents

HTTP 200 OK

Comparisons

HTTP 200 OK vs SIP 200 OK

Compare With

100 Trying 180 Ringing 181 Call Is Being Forwarded 182 Queued 183 Session Progress 199 Early Dialog Terminated 202 Accepted 204 No Notification 300 Multiple Choices 301 Moved Permanently 302 Moved Temporarily 305 Use Proxy

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

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 200 OK?

The request has succeeded. For INVITE, the call has been answered. For other methods, the action has been completed successfully.

When do you see SIP 200 OK?

When a call is answered (INVITE 200 OK), a registration succeeds (REGISTER 200 OK), or a subscription is accepted (SUBSCRIBE 200 OK).

How to fix SIP 200 OK?

No fix needed — this is a success response. The caller should send an ACK to complete the three-way handshake for INVITE transactions.