D HTTP Error Codes Supported by Policy

HTTP Error Codes supported by Policy for AM, SM, and UE Interfaces

Table D-1 HTTP Error codes and cause supported by Policy for AM, SM, and UE Interfaces for Notification

Error Code-Message	Cause Code	Description	Action
400 - Bad requests	INVALID_MSG_FORMAT	Tthe HTTP request has an invalid format.	POST retry with POST request If retry is exhausted, then terminate the transaction.
400 - Bad requests	MANDATORY_IE_INCORRECT	A mandatory IE for an HTTP method received a semantically incorrect request.	POST retry with POST request If retry is exhausted, then terminate the transaction.
400 - Bad requests	MANDATORY_IE_MISSING	A mandatory IE for an HTTP method is not included in the request.	POST retry with POST request If retry is exhausted, then terminate the transaction.
400 - Bad requests	UNSPECIFIED_MSG_FAILURE	The request is rejected due to unspecified client error.	POST retry with POST request If retry is exhausted, then terminate the transaction.
400 - Bad requests	ERROR_REQUEST_PARAMETERS	The HTTP request is rejected because the set of information needed by the PCF for UE Policy selection is incomplete for the decision to be made.	POST retry with POST request If retry is exhausted, then terminate the transaction.
401- Unauthorized	With header "WWW-Authenticate"	There will be a new function to enable retry for this error code.	POST retry with POST request If retry is exhausted, terminate the transaction
403-Forbidden	MODIFICATION_NOT_ALLOWED	The request is rejected because modification is not allowed.	POST retry with POST request If retry is exhausted, terminate the transaction
404 - Not Found	SUBSCRIPTION_NOT_FOUND	The request for modification or deletion of subscription is rejected because the subscription is not found in the NF.	POST retry with POST request If retry is exhausted, delete the session
404 - Not Found	RESOURCE_URI_STRUCTURE_NOT_FOUND	The request is rejected because a fixed part after the first variable part of an "apiSpecificResourceUriPart" is not found in the NF.	POST retry with POST request If retry is exhausted, delete the session
405 - Method Not Allowed	NA	If the NF supports the HTTP method for several resources in the API, but not for the target resource of a given HTTP request	POST retry with POST request If retry is exhausted, terminate the transaction
406 - Not Acceptable	NA	The server cannot generate a response in a format specified as acceptable by the client in the "Accept" headers.	POST retry with POST request If retry is exhausted, terminate the transaction
408 - Request Timeout	NA	The server did not receive a complete request from the client within the expected timeframe.	POST retry with POST request If retry is exhausted, terminate the transaction
409 - Conflict	NA	The server did not receive a complete request from the client within the expected timeframe.	POST retry with POST request If retry is exhausted, terminate the transaction
410 - Gone	NA	The server did not receive a complete request from the client within the expected timeframe.	POST retry with POST request If retry is exhausted, terminate the transaction
411 - Length Required	INCORRECT_LENGTH	The request is rejected due to incorrect valueof a Content-length header field.	POST retry with POST request If retry is exhausted, terminate the transaction
412 - Precondition Failed	NA	One or more preconditions specified in the request headers were not met.	POST retry with POST request If retry is exhausted, terminate the transaction
413 - Payload Too Large	NA	The server refuses to process the request because thepayload size exceeds its limitations.	POST retry with POST request If retry is exhausted, terminate the transaction
414 - URI Too Long	NA	The server cannot process the request because the provided URI exceeds its maximum length limit.	POST retry with POST request If retry is exhausted, terminate the transaction
415 - Unsupported Media Type	NA	The server cannot process the request due to an unsupported media type in the request payload.	POST retry with POST request If retry is exhausted, terminate the transaction
429 - Too Many Requests	NF_CONGESTION_RISK	The request is rejected due to excessive traffic which, if continued over time, may lead to (or may increase) an overload situation.	POST retry with POST request If retry is exhausted, terminate the transaction
500 - Server Side Issue	INSUFFICIENT_RESOURCES	The request is rejected due to insufficient resources.	POST retry with POST request If retry is exhausted, terminate the transaction
500 - Server Side Issue	UNSPECIFIED_NF_FAILURE	The request is rejected due to unspecified reason at the NF.	POST retry with POST request If retry is exhausted, terminate the transaction
500 - Server Side Issue	SYSTEM_FAILURE	The request is rejected due to generic error condition in the NF.	POST retry with POST request If retry is exhausted, terminate the transaction
500 - Server Side Issue	NF_FAILOVER	The request is rejected due to generic error condition in the NF.	POST retry with POST request If retry is exhausted, terminate the transaction
503 - Server temporarily unavailable	NF_CONGESTION	The NF experiences congestion and performs overload control, which does not allow the request to be processed.	POST retry with POST request If retry is exhausted, terminate the transaction

Policy as a producer of Error to AM Interface

Table D-2 Policy as a producer of Error to AM Interface

Message	Cause Code	Description
400 - Bad request	MANDATORY_IE_INCORRECT	When the SUPI was incorrectly written into the request body and sent to Ingress.
400 - Bad request	MANDATORY_IE_MISSING	When a request is sent without a mandatory IE (SUPI) in the request body.
400 - Bad request	UNSPECIFIED_MSG_FAILURE	When there is malformed JSON object.
400 - Bad request	USER_UNKNOWN	A correct request is sent with a SUPI that is not registered in the UDR. The validate-user in the CNC Console of the UE Policy is activated.
400 - Bad request	ERROR_REQUEST_PARAMETERS	When there is malformed JSON object.
400 - Bad request	PENDING_TRANSACTION	In case of Pending transaction.
401 - Unauthorized	With header "WWW-Authenticate"	Supported by Gateway service.
403 - Forbidden	MODIFICATION_NOT_ALLOWED	Supported by Gateway service.
404 - Not Found	SUBSCRIPTION_NOT_FOUND	When UE-Delete is sent with a polAssoId that does not exist in the database.
404 - Not Found	RESOURCE_URI_STRUCTURE_NOT_FOUND	When resource URI structure is not found.
408 - Request Timeout	NA	Supported by Gateway service.
411 - Length Required	INCORRECT_LENGTH	Incorrect length.
429 - Too Many Requests	NF_CONGESTION_RISK	When there is congestion risk in the NF.
500 - Internal Server Error	UNSPECIFIED_NF_FAILURE	When an unexpected error occurs within the service.
503 - Service Unavailable	NF_CONGESTION	Supported by Gateway service.

Policy as a producer of Error to SM

Table D-3 Policy as a producer of Error to SM

Message	Cause Code	Description
400 - Bad request	MANDATORY_IE_MISSING	A request is sent without a mandatory IE (SUPI) in the request body.
400 - Bad request	UNSPECIFIED_MSG_FAILURE	malformed json object.
400 - Bad request	USER_UNKNOWN	A correct request is sent, with a SUPI that is not registered in the UDR.We activate the validate-user in the UE Policy GUI.
400 - Bad request	ERROR_INITIAL_PARAMETERS	A request is sent with an error in one or more of its parameters
400 - Bad request	PENDING_TRANSACTION	This error shall be used when the PendingTransaction feature is supported and the AMF receives an incomingrequest on a policy association while it has an ongoingtransaction on the same policy association.
401- Unauthorized	With header "WWW-Authenticate"	Supported by Gateway service.
403 - Forbidden	MODIFICATION_NOT_ALLOWED	Supported by Gateway service.
403 - Forbidden	POLICY_CONTEXT_DENIED	When an error occurs in PRE service.
403 - Forbidden	LATE_OVERLAPPING_REQUEST	The request is rejected because it collides with an existing SM context or PDU session context with a more recent origination timestamp.
404 - Not Found	SUBSCRIPTION_NOT_FOUND	When UE-Delete is sent with a polAssoId that does not exist in the database.
404 - Not Found	RESOURCE_URI_STRUCTURE_NOT_FOUND	This error is being handled by IGW, never reachesthe core service, send 404 Not Found withoud cause.
408 - Request Timeout	NA	Supported by Gateway service.
411 - Length Required	INCORRECT_LENGTH	The error cause will be changed to ERROR_REQUEST_PARAMETERS.
429 - Too Many Requests	NF_CONGESTION_RISK	This will be supported with IGW congestion control and load shedding profiles.
500 - Internal Server Error	UNSPECIFIED_NF_FAILURE	The request is rejected due to unspecified reason at the NF.
503 - Service Unavailable	NF_CONGESTION	Supported by Gateway service.

Policy as a producer of Error to UE

Table D-4 Policy as a producer of Error to UE

Message	Cause Code	Description
400 - Bad request	MANDATORY_IE_INCORRECT	The SUPI was incorrectly written into the request body and sent to Ingress.
400 - Bad request	MANDATORY_IE_MISSING	A request is sent without a mandatory IE (SUPI) in the request body,the cases that are related to this cause will be handled asERROR_REQUEST_PARAMETERS.
400 - Bad request	UNSPECIFIED_MSG_FAILURE	When there is malformed JSON object.
400 - Bad request	USER_UNKNOWN	A correct request is sent, with a SUPI that is not registered in the UDR.We activate the validate-user in the UE Policy GUI.
400 - Bad request	ERROR_REQUEST_PARAMETERS	The HTTP request is rejected because the set ofinformation needed by the PCF for UE Policy selection isincomplete or erroneous or not available for the decision tobe made.
400 - Bad request	PENDING_TRANSACTION	This error shall be used when the PendingTransactionfeature is supported and the AMF receives an incomingrequest on apolicy association while it has an ongoingtransaction on the same policy association.
401 - Unauthorized	With header "WWW-Authenticate"	Supported by Gateway service.
403 - Forbidden	MODIFICATION_NOT_ALLOWED	Supported by Gateway service.
404 - Not Found	SUBSCRIPTION_NOT_FOUND	When UE-Delete is sent with a polAssoId that does not exist in the database.
404 - Not Found	RESOURCE_URI_STRUCTURE_NOT_FOUND	This error is being handled by IGW, never reaches the core service, send 404 Not Found without cause.
408 - Request Timeout	NA	Request gets timed out.
411 - Length Required	INCORRECT_LENGTH	The error cause will be changed to ERROR_REQUEST_PARAMETERS.
429 - Too Many Requests	NF_CONGESTION_RISK	This will be supported with IGW congestion controland load shedding profiles.
500 - Internal Server Error	UNSPECIFIED_NF_FAILURE	The request is rejected due to unspecified reason at the NF.
503 - Service Unavailable	NF_CONGESTION	Supported by Gateway service.

HTTP Error Codes supported by Policy for CHF and UDR Interfaces

Table D-5 Error codes and cause supported by Policy for CHF Interface

Message	Cause Code	Description	Actions
400 - Bad Request	INVALID_API	The HTTP request contains an unsupported API name or API version in the URI.	Session Retry using connector configuration with PUT and POST requests. After the session retry is exhausted, final error code for PUT or POST failure will reach core service for Policy evaluation.
400 - Bad Request	INVALID_MSG_FORMAT	The HTTP request has an invalid format.	Session Retry using connector configuration with PUT and POST requests. After the session retry is exhausted, final error code for PUT or POST failure will reach core service for Policy evaluation.
400 - Bad Request	INVALID_QUERY_PARAM	The HTTP request contains an unsupported query parameter in the URI.	Session Retry using connector configuration with PUT and POST requests. After the session retry is exhausted, final error code for PUT or POST failure will reach core service for Policy evaluation.
400 - Bad Request	MANDATORY_QUERY_PARAM_INCORRECT	A mandatory query parameter, or aconditional query parameter but mandatoryrequired, for an HTTP method was received in the URI with semantically incorrect value.	Session Retry using connector configuration with PUT and POST requests. After the session retry is exhausted, final error code for PUT or POST failure will reach core service for Policy evaluation.
400 - Bad Request	OPTIONAL_QUERY_PARAM_INCORRECT	A mandatory query parameter, or aconditional query parameter but mandatoryrequired, for an HTTP method was received in the URI with semantically incorrect value.	Session Retry using connector configuration with PUT and POST requests. After the session retry is exhausted, final error code for PUT or POST failure will reach core service for Policy evaluation.
400 - Bad Request	MANDATORY_QUERY_PARAM_MISSING	Query parameter which is defined asmandatory, or as conditional but mandatoryrequired, for an HTTP method is not included in the URI of the request.	Session Retry using connector configuration with PUT and POST requests. After the session retry is exhausted, final error code for PUT or POST failure will reach core service for Policy evaluation.
400 - Bad Request	MANDATORY_IE_INCORRECT	A mandatory IE or conditional IE butmandatory required, for an HTTP methodwas received with a semantically incorrect.	Session Retry using connector configuration with PUT and POST requests. After the session retry is exhausted, final error code for PUT or POST failure will reach core service for Policy evaluation.
400 - Bad Request	OPTIONAL_IE_INCORRECT	-	Session Retry using connector configuration with PUT and POST requests. After the session retry is exhausted, final error code for PUT or POST failure will reach core service for Policy evaluation.
400 - Bad Request	MANDATORY_IE_MISSING	A mandatory query parameter is missing in the HTTP request.	Session Retry using connector configuration with PUT and POST requests. After the session retry is exhausted, final error code for PUT or POST failure will reach core service for Policy evaluation.
400 - Bad Request	USER_UNKNOWN	The HTTP request is rejected because PCF received an unknown user.	Session Retry using connector configuration with PUT and POST requests. After the session retry is exhausted, final error code for PUT or POST failure will reach core service for Policy evaluation.
400 - Bad Request	NO_AVAILABLE_POLICY_COUNTERS	Policy counters are not available.	Session Retry using connector configuration with PUT and POST requests. After the session retry is exhausted, final error code for PUT or POST failure will reach core service for Policy evaluation.
400 - Bad Request	UNKNOWN_POLICY_COUNTERS	Policy counters are unknown.	Session Retry using connector configuration with PUT and POST requests. After the session retry is exhausted, final error code for PUT or POST failure will reach core service for Policy evaluation.
401 - Unauthorized	WWW-Authenticate	Unauthorized with Header "WWW-Authenticate"	Post Retry with POST request (Session retry) Put retry with POST (Revalidation/Reset context) If retry is exhausted, then terminate the transaction.
403 - Forbidden	Modification_Not_Allowed	Request is forbidden.	Retry with POST request If retry is exhausted, delete the session
404 - Not Found	SUBSCRIPTION_NOT_FOUND	The request for modification or deletion of a subscription is rejected because the subscription is not found in the NF.	Retry with POST request If retry is exhausted, delete the session
404 - Not Found	RESOURCE_URI_STRUCTURE_NOT_FOUND	Resource URI structure is not found.	Post Retry with POST request (Session retry) Put retry with POST (Revalidation/Reset context) If retry is exhausted, then terminate the transaction.
405 - Method Not Allowed	NA	The HTTP request is rejected as the performed operation is not allowed.	Post Retry with POST request (Session retry) Put retry with POST (Revalidation/Reset context) If retry is exhausted, then terminate the transaction.
406 - Not acceptable	NA	The request is not acceptable.	Post Retry with POST request (Session retry) Put retry with POST (Revalidation/Reset context) If retry is exhausted, then terminate the transaction.
409 - Conflict	NA	The request is rejected due to schema errors and conflicts in versions.	Post Retry with POST request (Session retry) Put retry with POST (Revalidation/Reset context) If retry is exhausted, then terminate the transaction.
410 - Gone	NA	This requested resource has been permanently deleted.	Post Retry with POST request (Session retry) Put retry with POST (Revalidation/Reset context) If retry is exhausted, then terminate the transaction.
411 - Length Required	NA	The HTTP request is rejected due to incorrect value of a Content-length header field.	Post Retry with POST request (Session retry) Put retry with POST (Revalidation/Reset context) If retry is exhausted, then terminate the transaction.
412 - Precondition Failed	NA	The request is rejected due to incorrect conditions in GET request.	Post Retry with POST request (Session retry) Put retry with POST (Revalidation/Reset context) If retry is exhausted, then terminate the transaction.
413 - Payload Too Large	NA	The payload is larger than the limit.	Post Retry with POST request (Session retry) Put retry with POST (Revalidation/Reset context) If retry is exhausted, then terminate the transaction.
414 - URI Too Long	NA	The request URI is longer than the limit.	Post Retry with POST request (Session retry) Put retry with POST (Revalidation/Reset context) If retry is exhausted, then terminate the transaction.
415 - Unsupported Media Type	NA	The HTTP request contains unsupported payload payload type.	Post Retry with POST request (Session retry) Put retry with POST (Revalidation/Reset context) If retry is exhausted, then terminate the transaction.
429 - Too many requests	NA	The request is rejected due to excessive traffic, which if continued over time, may lead to (or may increase) an overload situation.	Post Retry with POST request (Session retry) Put retry with POST (Revalidation/Reset context) If retry is exhausted, then terminate the transaction.
500 - Internal Server Error	NA	The request is rejected due to generic error condition in the NF.	Post Retry with POST request (Session retry) Put retry with POST (Revalidation/Reset context) If retry is exhausted, then terminate the transaction.
501 - Not Implemented	NA	The service operation cannot be implemented due to invalid resource URI to be monitored.	Post Retry with POST request (Session retry) Put retry with POST (Revalidation/Reset context) If retry is exhausted, then terminate the transaction.
503 - Service Unavailable	NA	The NF experiences congestion and performs overload control, which does not allow the request to be processed.	Post Retry with POST request (Session retry) Put retry with POST (Revalidation/Reset context) If retry is exhausted, then terminate the transaction.
504 - Gateway Timeout	NA	This error code is generated in case of timeout due to inactivity.	Post Retry with POST request (Session retry) Put retry with POST (Revalidation/Reset context) If retry is exhausted, then terminate the transaction.

Table D-6 Error codes and cause supported by Policy for UDR Interface.

Error Code - Message	Cause Code	Description	Action
400 - Bad Request	INVALID_API	The HTTP request contains an unsupported API name or API version in the URI.	Session Retry using connector configuration with PUT and POST requests. If retry is exhausted, terminate the transaction.
400 - Bad Request	INVALID_MSG_FORMAT	The HTTP request has an invalid format.	Session Retry using connector configuration with PUT and POST requests. If retry is exhausted, terminate the transaction.
400 - Bad Request	INVALID_QUERY_PARAM	The HTTP request contains an unsupported query parameter in the URI.	Session Retry using connector configuration with PUT and POST requests. If retry is exhausted, terminate the transaction.
400 - Bad Request	MANDATORY_QUERY_PARAM_INCORRECT	A mandatory query parameter, or aconditional query parameter but mandatoryrequired, for an HTTP method was received in the URI with semantically incorrect value.	Session Retry using connector configuration with PUT and POST requests. If retry is exhausted, terminate the transaction.
400 - Bad Request	OPTIONAL_QUERY_PARAM_INCORRECT	A mandatory query parameter, or aconditional query parameter but mandatoryrequired, for an HTTP method was received in the URI with semantically incorrect value.	Session Retry using connector configuration with PUT and POST requests. If retry is exhausted, terminate the transaction.
400 - Bad Request	MANDATORY_QUERY_PARAM_MISSING	Query parameter which is defined asmandatory, or as conditional but mandatoryrequired, for an HTTP method is not included in the URI of the request.	Session Retry using connector configuration with PUT and POST requests. If retry is exhausted, terminate the transaction.
400 - Bad Request	MANDATORY_IE_INCORRECT	A mandatory IE or conditional IE butmandatory required, for an HTTP methodwas received with a semantically incorrect.	Session Retry using connector configuration with PUT and POST requests. If retry is exhausted, terminate the transaction.
400 - Bad Request	OPTIONAL_IE_INCORRECT	-	Session Retry using connector configuration with PUT and POST requests. If retry is exhausted, terminate the transaction.
400 - Bad Request	MANDATORY_IE_MISSING	A mandatory query parameter is missing in theHTTP request.	Session Retry using connector configuration with PUT and POST requests. If retry is exhausted, terminate the transaction.
400 - Bad Request	USER_UNKNOWN	The HTTP request is rejected because PCF received an unknown user.	Session Retry using connector configuration with PUT and POST requests. If retry is exhausted, terminate the transaction.
401 -Unauthorized	WWW-Authenticate	Unauthorized with Header "WWW-Authenticate"	Post Retry with POST request (Session retry) Put retry with POST (Revalidation/Reset context) If retry is exhausted, terminate the transaction
403- Forbidden	Modification_Not_Allowed	Request is forbidden.	Retry with POST request
404 - Not Found	SUBSCRIPTION_NOT_FOUND	The request for modification or deletion of a subscription is rejected because the subscription is not found in the NF.	POST Retry with POST request (Session retry) Put retry with POST (Revalidation/Reset context) If retry is exhausted, delete the subscription
404 - Not Found	RESOURCE_URI_STRUCTURE_NOT_FOUND	Resource URI structure is not found.	Retry with POST request If retry is exhausted, terminate the transaction
404 - Not Found	USER_UNKNOWN	User is unknown.	Retry with POST request If retry is exhausted, terminate the transaction
405 - Method Not Allowed	NA	The HTTP request is rejected as the performed operation is not allowed.	Retry with POST request If retry is exhausted, terminate the transaction
406 - Not acceptable	NA	The request is not acceptable.	Retry with POST request If retry is exhausted, terminate the transaction
409 -Conflict	NA	The request is rejected due to schema errors and conflicts in versions.
410 - Gone	NA	This requested resource has been permanently deleted.	Retry with POST request If retry is exhausted, terminate the transaction
411 - Length Required	NA	The HTTP request is rejected due to incorrect value of a Content-length header field.	Retry with POST request If retry is exhausted, terminate the transaction
412 - Precondition Failed	NA	The request is rejected due to incorrect conditions in GET request.	Retry with POST request If retry is exhausted, terminate the transaction
413 - Payload Too Large	NA	The payload is larger than the limit.	Retry with POST request If retry is exhausted, terminate the transaction
414 - URI Too Long	NA	The request URI is longer than the limit.	Retry with POST request If retry is exhausted, terminate the transaction
415 - Unsupported Media Type	NA	The HTTP request contains unsupported payload payload type.	Retry with POST request If retry is exhausted, terminate the transaction
429 - Too many requests	NA	The request is rejected due to excessive traffic, which if continued over time, may lead to (or may increase) an overload situation.	NA
500 - Internal Server Error	NA	The request is rejected due to generic error condition in the NF.	Retry with POST request If retry is exhausted, terminate the transaction
501 - Not Implemented	NA	The service operation cannot be implemented due to invalid resource URI to be monitored.	Retry with POST request If retry is exhausted, terminate the transaction
503 - Service Unavailable	NA	The NF experiences congestion and performs overload control, which does not allow the request to be processed.	Retry with POST request If retry is exhausted, terminate the transaction
504 - Gateway Timeout	NA	This error code is generated in case of timeout due to inactivity.	Retry with POST request If retry is exhausted, terminate the transaction

Policy as a producer of Error for Notification for CHF Interface

Table D-7 Policy as a producer of Error for Notification for CHF Interface

Error Code - Message	Cause Code	Scenario
400 - Bad Request	MANDATORY_IE_MISSING	When SUPI is not present in the request body for update or terminate notification.
400 - Bad Request	INVALID_MESSAGE_FORMAT	When the request body does not adhere to update or terminate notification structure.
400 - Bad Request	invalid_API	The HTTP request contains an unsupported API name or API version in the URI.
404 - Not Found	RESOURCE_URI_STRUCTURE_NOT_FOUND	The notification URI is incorrect.
404 - Not Found	SUBSCRIPTION_NOT_FOUND	When the spendinglimit resource is not found in DB.
504 - Gateway Timeout	GATEWAY_TIMEOUT	This error code is generated in case of timeout due to inactivity.

Policy as a producer of Error for Notification for UDR Interface

Table D-8 Policy as a producer of Error for Notification for UDR Interface

Error Code - Message	Cause Code	Scenario
400 - Bad Request	INVALID_MESSAGE_FORMAT	When the request body does not adhere to update or terminate notification structure.
404 - Not Found	SUBSCRIPTION_NOT_FOUND	When the PolicyDataChangeNotification resource is not found in DB.
501 - Not Implemented	UNSUPPORTED_MONITORED_URI	When the PolicyDataChangeNotification received have resource other than smPolicyData,operatorSpecificData, amPolicyData, and UePolicySet.

HTTP Error Codes supported by Policy for NRF Interface

HTTP Error codes supported by Policy for NRF Interface:

Error Code - Message	Description	Action
400 - Bad Request	The Request contains invalid values.	Autonomous mode: The NF retries primary NRF configurable N times, if fails NF retries secondary NRF configurable M times. NF continues switching back and forth between primary and secondary NRF until success registration. The time interval between one attempt and another is configurable. On demand mode: NF retries non primary NRF, if Primary NRF fails. If non primary NRF fails, NF continues with call flow and shall not be able to deregister in NRF.
403 - Forbidden	Request is forbidden.	Autonomous mode: The NF retries primary NRF configurable N times, if fails NF retries secondary NRF configurable M times. NF continues switching back and forth between primary and secondary NRF until success registration. The time interval between one attempt and another is configurable. On demand mode: NF retries non primary NRF, if Primary NRF fails. If non primary NRF fails, NF continues with call flow and shall not be able to deregister in NRF.
404- Not Found	The request for modification or deletion of a subscription is rejected because the subscription is not found in the NF.	Autonomous mode: The NF retries primary NRF configurable N times, if fails NF retries secondary NRF configurable M times. NF continues switching back and forth between primary and secondary NRF until success registration. The time interval between one attempt and another is configurable. On demand mode: NF retries non primary NRF, if Primary NRF fails. If non primary NRF fails, NF continues with call flow and shall not be able to deregister in NRF.
405 - Method Not Allowed	The request method is not GET, PUT, PATCH or DELETE.	Autonomous mode: The NF retries primary NRF configurable N times, if fails NF retries secondary NRF configurable M times. NF continues switching back and forth between primary and secondary NRF until success registration. The time interval between one attempt and another is configurable. On demand mode: NF retries non primary NRF, if Primary NRF fails. If non primary NRF fails, NF continues with call flow and shall not be able to deregister in NRF.
411 - Length Required	The request is rejected due to incorrect value of a Content-length header field, or the header doesn't exist.	Autonomous mode: The NF retries primary NRF configurable N times, if fails NF retries secondary NRF configurable M times. NF continues switching back and forth between primary and secondary NRF until success registration. The time interval between one attempt and another is configurable. On demand mode: NF retries non primary NRF, if Primary NRF fails. If non primary NRF fails, NF continues with call flow and shall not be able to deregister in NRF.
500 - Internal Server Error	Internal error occurred in NRF.	Autonomous mode: The NF retries primary NRF configurable N times, if fails NF retries secondary NRF configurable M times. NF continues switching back and forth between primary and secondary NRF until success registration. The time interval between one attempt and another is configurable. On demand mode: NF retries non primary NRF, if Primary NRF fails. If non primary NRF fails, NF continues with call flow and shall not be able to deregister in NRF.
503 - Service Unavailable	Rejecting traffic for overload control.	Autonomous mode: The NF retries primary NRF configurable N times, if fails NF retries secondary NRF configurable M times. NF continues switching back and forth between primary and secondary NRF until success registration. The time interval between one attempt and another is configurable. On demand mode: NF retries non primary NRF, if Primary NRF fails. If non primary NRF fails, NF continues with call flow and shall not be able to deregister in NRF.

Table D-9 Policy as a producer of Error for Notification for NRF Interface

Message	Cause Code	Scenario
400 - Bad Request	INVALID_MSG_FORMAT	NRF terminates the notification transaction.
400 - Bad Request	MANDATORY_IE_INCORRECT	NRF terminates the notification transaction.
400 - Bad Request	OPTIONAL_IE_INCORRECT	NRF terminates the notification transaction.
400 - Bad Request	MANDATORY_IE_MISSING	NRF terminates the notification transaction.
400 - Bad Request	UNSPECIFIED_MSG_FAILURE	NRF terminates the notification transaction.
429 - Too Many Requests	NF_CONGESTION_RISK	NRF terminates the notification transaction.
500 - Internal Server Error	SYSTEM_FAILURE	NRF terminates the notification transaction.
503 - Service Unavailable	NA	NRF terminates the notification transaction.