SIP 199 Early Dialog Terminated vs 420 Bad Extension
SIP 199 (Early Dialog Terminated) is a 1xx Provisional response, while 420 (Bad Extension) is a 4xx Client Failure response. 199 indicates that a UAS can send this to indicate that an early dialog has been terminated. Used when forking results in multiple early dialogs. In contrast, 420 means that the server did not understand the protocol extension specified in a Require or Proxy-Require header. The Unsupported header lists the unknown extensions.
Beschreibung
A UAS can send this to indicate that an early dialog has been terminated. Used when forking results in multiple early dialogs.
Wann Sie es sehen
In forked call scenarios when one of the forked branches is cancelled because another branch was answered.
Wie man es behebt
No action needed. This is normal behavior in forked call setups. Ensure your UA handles early dialog termination gracefully.
Beschreibung
The server did not understand the protocol extension specified in a Require or Proxy-Require header. The Unsupported header lists the unknown extensions.
Wann Sie es sehen
When the request includes a Require header with SIP extensions that the server does not support.
Wie man es behebt
Check the Unsupported header in the response. Remove the unsupported extension from the Require header or make it optional via Supported.
Wesentliche Unterschiede
199 is a 1xx Provisional response, while 420 is a 4xx Client Failure response.
SIP 199: A UAS can send this to indicate that an early dialog has been terminated. Used when forking results in multiple early dialogs.
SIP 420: The server did not understand the protocol extension specified in a Require or Proxy-Require header. The Unsupported header lists the unknown extensions.
You encounter 199 when in forked call scenarios when one of the forked branches is cancelled because another branch was answered.
You encounter 420 when when the request includes a Require header with SIP extensions that the server does not support.
Wann welchen verwenden
For 199 (Early Dialog Terminated): No action needed. This is normal behavior in forked call setups. Ensure your UA handles early dialog termination gracefully. For 420 (Bad Extension): Check the Unsupported header in the response. Remove the unsupported extension from the Require header or make it optional via Supported.