SIP 180 Ringing vs 604 Does Not Exist Anywhere
SIP 180 (Ringing) is a 1xx Provisional response, while 604 (Does Not Exist Anywhere) is a 6xx Global Failure 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, 604 means that the server has authoritative information that the user indicated in the Request-URI does not exist anywhere. Unlike 404, this is a definitive, global statement.
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 server has authoritative information that the user indicated in the Request-URI does not exist anywhere. Unlike 404, this is a definitive, global statement.
Quando você o vê
When the user definitively does not exist on any server in the network. The server has authoritative knowledge, not just local.
Como corrigir
The user does not exist. Verify the SIP URI or phone number. Unlike 404, retrying on other servers will not help.
Diferenças principais
180 is a 1xx Provisional response, while 604 is a 6xx Global Failure 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 604: The server has authoritative information that the user indicated in the Request-URI does not exist anywhere. Unlike 404, this is a definitive, global statement.
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 604 when when the user definitively does not exist on any server in the network. The server has authoritative knowledge, not just local.
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 604 (Does Not Exist Anywhere): The user does not exist. Verify the SIP URI or phone number. Unlike 404, retrying on other servers will not help.