SIP 180 Ringing vs 407 Proxy Authentication Required
SIP 180 (Ringing) is a 1xx Provisional response, while 407 (Proxy Authentication Required) 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, 407 means that the client must first authenticate with the proxy. The proxy returns a Proxy-Authenticate header with a challenge.
Description
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.
When You See It
During call setup when the callee's phone is ringing. You should hear a ringback tone after receiving this response.
How to Fix
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.
Description
The client must first authenticate with the proxy. The proxy returns a Proxy-Authenticate header with a challenge.
When You See It
When a SIP proxy requires authentication before forwarding the request. Similar to 401 but for proxy servers.
How to Fix
Resend the request with a Proxy-Authorization header containing valid credentials for the proxy.
Key Differences
180 is a 1xx Provisional response, while 407 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 407: The client must first authenticate with the proxy. The proxy returns a Proxy-Authenticate header with a challenge.
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 407 when when a SIP proxy requires authentication before forwarding the request. Similar to 401 but for proxy servers.
When to Use Which
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 407 (Proxy Authentication Required): Resend the request with a Proxy-Authorization header containing valid credentials for the proxy.