183
SIP
183 Session Progress
Used to convey information about the progress of the call that is not otherwise classified. Often carries early media (ringback tones, announcements) via SDP.
このコードが表示される場合
During call setup, especially in PSTN interworking scenarios. The response may contain SDP for early media like custom ringback tones or IVR prompts.
解決方法
No fix needed — this is informational. If early media is not playing, check codec negotiation and SDP handling in your UA.
比較対象
ガイド
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Security & Authentication
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Real-Time Protocols
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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
用語集
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Port Number
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Codec Negotiation
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VoIP (Voice over IP)
Presence (SIP)
PBX (Private Branch Exchange)
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TLS Versions