SIP 180 Ringing vs 200 OK
SIP 180 (Ringing) is a 1xx Provisional response, while 200 (OK) is a 2xx Success response. 180 indicates that the UA receiving the INVITE is trying to alert the user. This response is used to initiate local ringback tone at the caller's end. In contrast, 200 means that the request has succeeded. For INVITE, the call has been answered. For other methods, the action has been completed successfully.
Descrição
The UA receiving the INVITE is trying to alert the user. This response is used to initiate local ringback tone at the caller's end.
Quando você o vê
During call setup when the callee's phone is ringing. You should hear a ringback tone after receiving this response.
Como corrigir
No fix needed — the callee's device is ringing. If the call never connects after ringing, check the callee's device or call forwarding settings.
Descrição
The request has succeeded. For INVITE, the call has been answered. For other methods, the action has been completed successfully.
Quando você o vê
When a call is answered (INVITE 200 OK), a registration succeeds (REGISTER 200 OK), or a subscription is accepted (SUBSCRIBE 200 OK).
Como corrigir
No fix needed — this is a success response. The caller should send an ACK to complete the three-way handshake for INVITE transactions.
Diferenças principais
180 is a 1xx Provisional response, while 200 is a 2xx Success response.
SIP 180: The UA receiving the INVITE is trying to alert the user. This response is used to initiate local ringback tone at the caller's end.
SIP 200: The request has succeeded. For INVITE, the call has been answered. For other methods, the action has been completed successfully.
You encounter 180 when during call setup when the callee's phone is ringing. You should hear a ringback tone after receiving this response.
You encounter 200 when when a call is answered (INVITE 200 OK), a registration succeeds (REGISTER 200 OK), or a subscription is accepted (SUBSCRIBE 200 OK).
Quando usar qual
For 180 (Ringing): No fix needed — the callee's device is ringing. If the call never connects after ringing, check the callee's device or call forwarding settings. For 200 (OK): No fix needed — this is a success response. The caller should send an ACK to complete the three-way handshake for INVITE transactions.