SIP 180 Ringing vs 437 Unsupported Certificate
SIP 180 (Ringing) is a 1xx Provisional response, while 437 (Unsupported Certificate) is a 4xx Client 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, 437 means that the server was unable to validate the certificate referenced by the Identity-Info header. The certificate may be self-signed or from an untrusted CA.
Mô tả
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.
Khi bạn thấy mã này
During call setup when the callee's phone is ringing. You should hear a ringback tone after receiving this response.
Cách khắc phục
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.
Mô tả
The server was unable to validate the certificate referenced by the Identity-Info header. The certificate may be self-signed or from an untrusted CA.
Khi bạn thấy mã này
When the signing certificate for SIP Identity validation is not trusted by the verifying server.
Cách khắc phục
Use a certificate from a trusted Certificate Authority. Ensure the certificate chain is complete and not expired.
Sự khác biệt chính
180 is a 1xx Provisional response, while 437 is a 4xx Client 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 437: The server was unable to validate the certificate referenced by the Identity-Info header. The certificate may be self-signed or from an untrusted CA.
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 437 when when the signing certificate for SIP Identity validation is not trusted by the verifying server.
Khi nào dùng cái nào
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 437 (Unsupported Certificate): Use a certificate from a trusted Certificate Authority. Ensure the certificate chain is complete and not expired.