486
SIP
486 Busy Here
The callee's end system was contacted successfully but the callee is currently not willing or able to take additional calls at this end system.
Khi bạn thấy mã này
When the callee is already on a call and does not have call waiting. The user explicitly rejected the call, or all lines are in use.
Cách khắc phục
Wait and try again later. The callee may become available when their current call ends. Consider leaving a voicemail if available.
Đặc tả
Mã liên quan
So sánh
So sánh với
Hướng dẫn
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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
Đặc tả
Thuật ngữ
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