439
SIP
439 First Hop Lacks Outbound Support
The first outbound proxy does not support the SIP outbound mechanism (RFC 5626) that the UA is trying to use.
Quando você vê este código
When a UA configured for SIP outbound connects to a proxy that doesn't support the outbound option-tag.
Como corrigir
Upgrade the outbound proxy to support RFC 5626, or configure the UA to not require outbound support.
Especificação
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Protocol Deep Dives
Glossário
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