7.2. Error Bit

The 'E' (Error Bit) in the Diameter header is set when the request caused a protocol-related error (see Section 7.1.3). A message with the 'E' bit MUST NOT be sent as a response to an answer message. Note that a message with the 'E' bit set is still subjected to the processing rules defined in Section 6.2. When set, the answer message will not conform to the CCF specification for the command; instead, it will conform to the following CCF:

Message Format

 ::= < Diameter Header: code, ERR [, PXY] >
 0*1< Session-Id >
 { Origin-Host }
 { Origin-Realm }
 { Result-Code }
 [ Origin-State-Id ]
 [ Error-Message ]
 [ Error-Reporting-Host ]
 [ Failed-AVP ]
 [ Experimental-Result ]
 * [ Proxy-Info ]
 * [ AVP ]

Note that the code used in the header is the same than the one found in the request message, but with the 'R' bit cleared and the 'E' bit set. The 'P' bit in the header is set to the same value as the one found in the request message.

7.2. Error Bit​

7.2. Error Bit