6 Services offered by Edge Configuration Server

29.5583GPPApplication Programming Interface (API) specificationEnabling Edge ApplicationsRelease 18Stage 3TS

Tools: ARFCN - Frequency Conversion for 5G NR/LTE/UMTS/GSM

6.1 Introduction

The table 6.1-1 lists the Edge Configuration Server APIs below the service name. A service description clause for each API gives a general description of the related API.

Table 6.1-1: List of ECS Service APIs

Service Name	Service Operations	Operation Semantics	Consumer(s)
Eecs_EESRegistration	Request	Request/Response	EES
	Update	Request/Response	EES
	Deregister	Request/Response	EES
Eecs_TargetEESDiscovery	Request	Request/Response	EES

Table 6.1-2 summarizes the corresponding Edge Configuration Server APIs defined in this specification.

Table 6.1-2: API Descriptions

Service Name	Clause	Description	OpenAPI Specification File	apiName	Annex
Eecs_EESRegistration	9.1	EES registration service.	TS29558_Eecs_EESRegistration.yaml	eecs-eesregistration	A.11
Eecs_TargetEESDiscovery	9.2	Service to discover the target EES information.	TS29558_Eecs_TargetEESDiscovery.yaml	eecs-targeteesdiscovery	A.12

6.2 Eecs_EESRegistration Service

6.2.1 Service Description

The Eecs_EESRegistration API, as defined in 3GPP TS 23.558 [2], allows an Edge Enabler Server via Eecs interface to register, update its registration and deregister at a given Edge Configuration Server.

6.2.2 Service Operations

6.2.2.1 Introduction

The service operation defined for Eecs_EESRegistration API is shown in the table 6.2.2.1-1.

Table 6.2.2.1-1: Operations of the Eecs_EESRegistration API

Service operation name	Description	Initiated by
Eecs_EESRegistraiton_Request	This service operation is used by the EES to register itself to a given ECS.	EES
Eecs_EESRegistraiton_Update	This service operation is used by the EES to update its registration information at ECS.	EES
Eecs_EESRegistraiton_Deregister	This service operation is used by the EES to deregister itself from a given ECS.	EES

6.2.2.2 Eecs_EESRegistration_Request

6.2.2.2.1 General

This service operation is used by EES to register itself to a given ECS.

6.2.2.2.2 EES registering to ECS using Eecs_EESRegistration_Request operation

To register itself as an Edge Enabler Server at the ECS, the EES shall send an HTTP POST message to the Edge Configuration Server on the "EES Registrations" collection resource. The body of the HTTP POST message shall include the EES profile information, may include proposed expiration time for the registration, as specified in clause 9.1.2.2.3.1.

Upon receiving the HTTP POST message from the EES, the ECS shall:

1. Process the EES registration request information;

2. verify the identity of the Edge Enabler Server and check if the EES is authorized to register itself at ECS ;

3. if the EES is authorized to register to ECS, then the ECS shall;

a. store the EES profile and create a new resource with the EES registration information as specified in clause 9.1.2.1;

b. return the EES registration information, the resource URI of the EES registration information, in the "201 Created" response message. It shall include a Location HTTP header field. The Location header field shall contain the URI of the created registration i.e. {apiRoot}/eecs-eesregistration/<apiVersion>/registrations/{registrationId}. The response message may include expiration time to indicate when the EES registration will automatically expire.

On failure, the ECS shall take proper error handling actions, as specified in clause 9.1.6, and respond to the EES with an appropriate error status code.

If the expiration time is provided, then to maintain the registration, the EES shall send a registration update request (as described in clause 6.2.2.3) prior to the expiration time. If the registration update request is not sent before the expiry time, then the ECS shall treat the EES as deregistered and remove the corresponding EES registration resource.

6.2.2.3 Eecs_EESRegistration_Update

6.2.2.3.1 General

This service operation is used by EES to update its registration information at a given ECS.

6.2.2.3.2 EES updating registration information using Eecs_EESRegistration_Update operation

To update the EES registration information at the ECS, the EES shall send a HTTP PUT or PATCH message to the Edge Configuration Server on resource URI identifying the individual EES registration resource representation, as specified in clause 9.1.2.3.3.2 for HTTP PUT message and in clause 9.1.2.3.3.4 for HTTP PATCH message. The HTTP PUT message shall replace all properties in the existing resource with the EES registration information in the request. The EESRegistration data type in the request body of the HTTP PUT message shall include the EES profile information, and may include proposed expiration time to update the registration. This request shall not replace the eesId property of the existing resource.

The HTTP PATCH request message in the EESRegistrationPatch data type includes parameters (EES Profile, and/or expiry time) that need to be replaced in the existing Individual EAS registration resource. This request shall not replace the eesId property of the existing resource.

Upon receiving the HTTP PUT or PATCH message from the EES, the ECS shall:

1. check the registration update message from the EES to see if the EES is authorized to modify the requested registration resource;

2. if the EES is authorized to update the registration information:

a. update the resource identified by Resource URI of the EES registration information with the updated EES registration information received in the HTTP PUT or PATCH request message;

b. return the updated EES registration information in the "200 OK" response message or respond with the "204 No Content" message indicating to the EES that the EES registration information is updated successfully. In the response message, the ECS may provide an updated expiration time to indicate to the EES when the updated registration will automatically expire.

On failure, the ECS shall take proper error handling actions, as specified in clause 9.1.6, and respond to the EES with an appropriate error status code.

If the ECS determines that the received HTTP PUT or PATCH request needs to be redirected, the ECS may respond with an HTTP "307 Temporary Redirect" status code or an HTTP "308 Permanent Redirect" status code including an HTTP "Location" header containing an alternative URI representing the end point of an alternative ECS where the message should be redirected. Redirection handling is described in clause 5.2.10 of 3GPP TS 29.122 [6].

If the expiration time is provided, then to maintain the registration, the EES shall send a registration update prior to registration expiry time. If the registration update request is not sent before the expiry time, then the ECS shall treat EES as deregistered and remove the corresponding EES registration resource.

6.2.2.4 Eecs_EESRegistration_Deregister

6.2.2.4.1 General

This service operation is used by EES to deregister itself from a given ECS.

6.2.2.4.2 EES deregistering from ECS using Eecs_EESRegistration_Deregister operation

To deregister itself from the ECS, the EES shall send HTTP DELETE message to the ECS, on the resource URI identifying the individual EES registration resource representation as specified in clause 9.1.2.3.3.3. Upon receiving the HTTP DELETE request, the ECS shall:

1. verify the identity of the EES and check if the EES is authorized to deregister the EES registration information;

2. if the EES is authorized to deregister the EES registration information, then the ECS shall deregister the EES profile from the ECS and delete the resource representing EES registration information.

3. return the "204 Not Content" message to the EES, indicating the successful deregistration of the EES information.

On failure, the ECS shall take proper error handling actions, as specified in clause 9.1.6, and respond to the EES with an appropriate error status code.

If the ECS determines that the received HTTP DELETE request needs to be redirected, the ECS may respond with an HTTP "307 Temporary Redirect" status code or an HTTP "308 Permanent Redirect" status code including an HTTP "Location" header containing an alternative URI representing the end point of an alternative ECS where the message should be redirected. Redirection handling is described in clause 5.2.10 of 3GPP TS 29.122 [6].

6.3 Eecs_TargetEESDiscovery Service

6.3.1 Service Description

The Eecs_TargetEESDiscovery API, as defined in 3GPP TS 23.558 [2], allows an Edge Enabler Server via Eecs interface to retrieve the target EES (T-EES) information at a given ECS.

6.3.2 Service Operations

6.3.2.1 Introduction

The service operation defined for Eecs_TargetEESDiscovery API is shown in the table 6.3.2.1-1.

Table 6.3.2.1-1: Operations of the Eecs_TargetEESDiscovery API

Service operation name	Description	Initiated by
Eecs_TargetEESDiscovery_Request	This service operation is used by the S-EES to retrieve the T-EES information.	EES

6.3.2.2 Eecs_TargetEESDiscovery_Request

6.3.2.2.1 General

This service operation is used by the S-EES to retrieve the T-EES information from the ECS.

6.3.2.2.2 EES fetching the T-EES information from the ECS using Eecs_TargetEESDiscovery_Request operation

To retrieve the T-EES information from the ECS, the S-EES shall send a HTTP GET message to the Edge Configuration Server on the "EES Profiles" collection resource as specified in clause 9.2.2.2.3.1. The S-EES includes the discovery filter information in the query parameters of the GET message, to assist the ECS to determine the T-EES that has the EAS available to serve the given AC in the UE. The query parameters shall include identifier of the S-EES, identifier of the S-EAS and may include target DNAI, UE location information, and UE identity.

Upon receiving the HTTP GET message from the EES, the ECS shall:

1. Process the EES request information;

2. verify the identity of the Edge Enabler Server and check if the EES is authorized to retrieve the T-EES information;

3. if the EES is authorized to retrieve the T-EES information, then the ECS shall;

a. determine the T-EES(s) as per UE location information, target DNAI and S-EAS in the request. If UE location information is not included or not known to the ECS, then the ECS may fetch the UE location information from the 3GPP core network as specified in 3GPP TS 29.522 [10];

b. returns the 200 OK message including the EDN configuration and the list of T-EES(s) information to the S-EES. The list of T-EES(s) includes the endpoint information to reach the T-EES(s).

On failure, the ECS shall take proper error handling actions, as specified in clause 9.2.6, and respond to the EES with an appropriate error status code.