408
SIP
408 Request Timeout
The server could not produce a response within a suitable time. The client may repeat the request without modifications at any later time.
Khi bạn thấy mã này
When the callee does not respond within the configured timeout (e.g., phone rings but is never answered, or the endpoint is unreachable).
Cách khắc phục
Check if the callee's device is powered on and registered. Verify network connectivity. Consider adjusting the server's transaction timeout value.
Đặc tả
Các mã tương đương giữa các giao thức
So sánh với
Hướng dẫn
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
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