SIP 100 Trying vs 603 Decline
SIP 100 (Trying) is a 1xx Provisional response, while 603 (Decline) is a 6xx Global Failure response. 100 indicates that the request has been received by the next-hop server and an unspecified action is being taken to process it. The UAC should expect additional responses. In contrast, 603 means that the callee's machine was contacted successfully but the user explicitly does not wish to or cannot participate. Unlike 600, this may be because the callee doesn't want to communicate, not necessarily
설명
The request has been received by the next-hop server and an unspecified action is being taken to process it. The UAC should expect additional responses.
이 코드를 보게 되는 경우
Immediately after sending an INVITE. The proxy has received the call and is searching for the callee. This is the SIP equivalent of a dial tone.
해결 방법
No fix needed — this is normal call setup behavior. If stuck on 100 Trying for too long, check network connectivity and proxy configuration.
설명
The callee's machine was contacted successfully but the user explicitly does not wish to or cannot participate. Unlike 600, this may be because the callee doesn't want to communicate, not necessarily because they're busy.
이 코드를 보게 되는 경우
When the callee explicitly declines the call. This is an active rejection, not a busy or unavailable state.
해결 방법
The callee has declined. Respect their decision. Consider alternative communication methods (email, messaging).
주요 차이점
100 is a 1xx Provisional response, while 603 is a 6xx Global Failure response.
SIP 100: The request has been received by the next-hop server and an unspecified action is being taken to process it. The UAC should expect additional responses.
SIP 603: The callee's machine was contacted successfully but the user explicitly does not wish to or cannot participate. Unlike 600, this may be because the callee doesn't want to communicate, not necessarily
You encounter 100 when immediately after sending an INVITE. The proxy has received the call and is searching for the callee. This is the SIP equivalent of a dial tone.
You encounter 603 when when the callee explicitly declines the call. This is an active rejection, not a busy or unavailable state.
언제 어떤 것을 사용할지
For 100 (Trying): No fix needed — this is normal call setup behavior. If stuck on 100 Trying for too long, check network connectivity and proxy configuration. For 603 (Decline): The callee has declined. Respect their decision. Consider alternative communication methods (email, messaging).