Callout Server

API Documentation

The O-RAN SC external call-out server allows behavioral extensions to be added to the A1 Simulator. It creates an external call-out server, which provides a RESTful API. A1 Policy operations, for some A1 Policy Types, can then be redirected to the external call-out server, supporting supplemental simulator behavior for those A1 Policy Types.

Note: call-out server functionality is only available for ‘STD_2.0.0’ version simulators.

The external call-out server exposes a ‘Callout server API’ REST API. This internal API is invoked directly by the A1 Simulator, and is not intended to be used by any other client. The ‘Callout Server API’ is documented in Callout Server API and in OpenAPI YAML format:

API name
Callout Server API	link

External call-out servers also expose an ‘Admin API’ to manipulate the behavior of the call-out server itself. The ‘Callout Server Admin API’ is documented below:

Admin Functions

Health Check

GET

Returns the status of the external server.

URL path:

/

Parameters:

None.

Responses:

200:

OK

Examples:

Call:

curl -X GET "http://localhost:9095/"

Result:

200:

OK

Delete all policy instances in external server

POST

Delete all policy instances.

URL path:

/serveradmin/deleteinstances

Parameters:

None.

Responses:

200:

All a1 policy instances deleted

Examples:

Call:

curl -X POST "http://localhost:9095/serveradmin/deleteinstances"

Result:

200:

All a1 policy instances deleted

Response manipulation

It is possible to manipulate the response of all operations on the external server

POST

Force a specific response code for the all (the next) external server operation. Unless it is reset, it will always send the same response code back.

URL path:

/serveradmin/forceresponse?code=<http-response-code>

Parameters:

code: (Required)

The HTTP response code to return.

Responses:

200:

Force response code: <expected code> set for all external server response until it is resetted

Examples:

Call:

curl -X POST "http://localhost:9095/serveradmin/forceresponse?code=500"

Result:

200:

Force response code: 500 set for all external server response until it is resetted

Reset response-manipulation

It is possible to reset the response manipulation on the external server

POST

Clears specific response code for all (the next) external server operation.

URL path:

/serveradmin/forceresponse?code=<http-response-code>

Parameters:

code: (Required)

The HTTP response code to return.

Responses:

200:

Force response code has been resetted for all external server responses

Examples:

Call:

curl -X POST "http://localhost:9095/serveradmin/forceresponse?code=500"

Result:

200:

Force response code has been resetted for all external server responses

Response time manipulation

It is possible to set a period of time to delay response time.

POST

Force delayed response of all A1 responses. The setting will remain until the delay is set to ‘0’

URL path:

/serveradmin/forcedelay?delay=<delay-time-seconds>

Parameters:

delay: (Required)

The time in seconds to delay all responses.

Responses:

200:

Force delay: <expected_delay> sec set for all external server responses until it is resetted

Examples:

Call:

curl -X POST "http://localhost:9095/serveradmin/forcedelay?delay=5"

Result:

200:

Force delay: 5 sec set for all external server responses until it is resetted

Reset response time manipulation

It is also possible to reset delay response time.

POST

The setting will clear the delay.

URL path:

/serveradmin/forcedelay

Parameters:

None.

The time in seconds to delay all responses.

Responses:

200:

Force delay has been resetted for all external server responses

Examples:

Call:

curl -X POST "http://localhost:9095/serveradmin/forcedelay"

Result:

200:

Force delay has been resetted for all external server responses