11. Appendix

11.1 A1

Examples of Attribute Categories per Self-Description in Gaia-X are discussed in Appendix A.

  • Providers: Every Provider of Service Offerings has to be registered as Provider and thus requires a Self-Description. The categories comprise identity, contact information, certification.

  • Nodes: Self-Descriptions of Nodes describe relevant functional and non-functional attributes of Nodes as described in Section “Basic Architecture Elements”. The Attribute Categories comprise availability, connectivity, hardware, monitoring, physical security and sustainability.

  • Software Assets: Self-Descriptions of Software Assets describe Software Assets as defined in the Conceptual Model. Attribute Categories for Software Assets are still under discussion and are not yet finalized.

  • Consumers (optional): Self-Descriptions of Consumers are optional, but may be required for accessing critical Data Assets and/or specific domains. Attribute categories for Consumers are still under discussion and are not yet finalized.

11.2 A2

Operational example Federated Trust Model

The Federated Trust Model is currently being updated, the new version will appear here in the next version of this document.

11.3 A3

This appendix presents minimal core versions of central Gaia-X concepts of the Conceptual Model. That includes mandatory attributes as well as their types and cardinalities for the core concepts of Participant, its special case Provider, Service Offering, Asset, Data Asset (and Data Service Offering as a special case of Service Offering, representing the service through which a Data Asset is provided), Software Asset, Node, and Interconnection.

11.3.1 Governance of Mandatory Attributes

The following lists of mandatory attributes reflect the consensus of stakeholder workshops held by the Self-Description Work Package. The proposer of each mandatory attribute was required to justify why it should be mandatory.

Anticipating further specializations of the Self-Description Schemas, future Architecture Document releases may instead refer to a dedicated, separate Self-Description document and an official Federated Catalogue hosting the Self-Description Schemas that implement the mandatory attributes. Future changes to the mandatory attributes, including additions, modifications, as well as deprecations, will be handled through the ADR process or a specialization of it. Mandatory attributes that, in future, are deemed to no longer be mandatory, or to no longer be applicable at all, shall not be deleted, but be deprecated as specified in OWL1

11.3.2 Semantics of Mandatory Attributes

The focus of this section is on mandatory attributes, i.e., those for which at least one value must be specified. Other attributes, which are of interest but optional, are out of scope of this revision of the Architecture Document. Technically, the presence or absence of a mandatory attribute in a Self-Description is checked by a validation shape. This validation mechanism only has access to the Self-Description and to the validation shapes, not to an oracle that provides further information about the real world. Thus, attributes are specified as either mandatory or non-mandatory. It is not technically possible to specify that an information should be mandatory if a certain situation holds in reality, e.g., that a Provider’s parent entity must be specified if the Provider has a parent entity.

For some attributes, it it recommended to use values from Controlled Vocabularies. Gaia-X specific controlled vocabularies have not yet been standardized. In future, they may be standardized according to a similar process as the specification of mandatory attributes. All such URIs given below serve as examples. The semantics of these terms may be fixed later.

11.3.3 Participant

Unless mentioned otherwise, the following attributes have identifiers in the http://w3id.org/gaia-x/participant# namespace, abbreviated with the gax-participant: prefix (e.g., gax-participant:hasLegallyBindingName).

Attribute Description Type(s) Cardinality Example value
hasLegallyBindingName legal name xsd:string 1..1 “SAP SE”
hasLegallyBindingAddress legal address vcard:Address 1..1 (a structured object having, e.g., the attributes vcard:street-address, vcard:locality and vcard:country-name)

11.3.3.1 Provider / Consumer

A Participant implicitly becomes a Provider once they provide (i.e., possess/operate/define) at least one Asset, Resource or ServiceOffering. They implicitly become a Consumer once they consume at least one ServiceInstance. To a Provider, the following additional mandatory attributes apply:

Attribute Description Possible Type(s) Cardinality Example Value
hasLegalForm legal form xsd:string or controlled vocabulary entry (URI) 1..1 https://gaia-x.eu/vocab/legal/Societas_Europeana
hasJurisdiction jurisdiction xsd:string or controlled vocabulary entry, e.g., country (URI) 1..1 http://gaia-x.eu/vocab/country/DE
hasSalesTaxID sales tax ID / VAT ID xsd:string 1..1 “DE 129515865” (in Germany)
hasLegalRegistrationNumber legal registration number xsd:string 1..1 “HRB 1234” (in Germany)
hasWebAddress web address xsd:anyURI 1..* https://gaia-x.eu/
hasIndividualContactLegal contact person for legal purposes vcard:Agent, schema:Person 1..* (a structured object having, e.g., the attributes schema:givenName and schema:email)
hasIndividualContactTechnical contact person for technical purposes vcard:Agent, schema:Person 1..* (a structured object having, e.g., the attributes schema:givenName and schema:email)

11.3.4 Service Offering

Attribute Description Possible Type(s) Cardinality Example Value
hasServiceTitle Name of the service xsd:string 1..1 “Image classification ML service”
hasServiceDescription A description in natural language dct:description 1..1 “An ML service for easily training, deploying, and improving image classifiers.”
hasKeyword dcat:keyword 1..n “Machine Learning”, “Classification”
providedBy This service’s provider(s) gax-participant:Provider 1..* gax:Company-1
hasProvisionType Provision type xsd:string or controlled vocabulary entry (URI) 1..1 “Hybrid” / gax:PrivateProvisioning
hasServiceModel Service model xsd:string or controlled vocabulary entry (URI) 1..1 “IaaS” / “PaaS” / “SaaS”
hasWebAddress URL of the service website xsd:anyURI 1..1 http://example.org/ML-classification-service

11.3.4.1 Asset

As of the 21.09 Architecture Document, Assets are no longer part of the Conceptual Model. The mandatory attributes for describing the similar concept of Resource are given below. A further revision of the Resource mandatory attributes, aligned with the ones of the former Asset concept, is expected for 2021-Q4.

Attribute Possible Datatype(s) Cardinality
name xsd:string 1..1
description dct:description 1..1
owned_by foaf:Person 1..*

11.3.4.2 Data Asset / Software Asset

Data Asset and Software Asset are subclasses of Asset that do not require additional mandatory attributes.

11.3.5 Data Service Offering

Attribute Description Possible Type(s) Cardinality Example Value
hasServiceTitle Title of the data service featuring a high level description for quick reference. xsd:string 1..1 “Example Data”
hasServiceDescription A more detailed description incl. markdown of the data service that contains all information not included in standardized Self Descriptions dct:description 1..1 “This data service contains the data resource formerly kept in my data silo.”
hasLicense Reference to the license model of the data service xsd:string or controlled vocabulary entry (URI) 1..1 “Public Domain”, https://creativecommons.org/publicdomain/zero/1.0/, “CC-BY”, “No License Specified”
hasCopyrightHolder Reference to the author or copyright holder as name or DID xsd:string 1..1 “Satoshi Nakamoto”, did:3:bafyreigh5aiij5xltuqcf5n4dcssgzcvg775cef3o2gcd7z7ssbn5w3sae
hasType Type of the data asset, which helps the discovery process. xsd:string or controlled vocabulary entry (URI) 1..1 “dataset”, http://gaia-x.eu/vocab/assetTypes/Algorithm, “container”, “video stream”, “audio stream”, …
wasCreatedOn The timestamp the data service has been created. ISO 8601 format, Coordinated Universal Time. xsd:dateTimeStamp 1..1 2021-07-17T00:31:30Z
conformsToStandard Provides information about standards applied, e.g., ISO 10303. xsd:string or controlled vocabulary entry (URI) 1..n “ISO10303-242:2014”, http://gaia-x.eu/vocab/standards/ISO_13567-1_2017
hasStandardReference Provides a link to the schema or additional details about the underlying standards applied, in case this link is not attached to the representation of the standard in a controlled vocabulary xsd:anyURI 1..n https://www.iso.org/standard/57620.html

11.3.6 Example for an Extension of a Data Service Offering (File)

If the underlying resource is a file this might require different attributes than streams or software products. This shall illustrate an example for a simple data service that serves a file that is available for download or computation.

The mandatory attributes are:

Attribute Description Possible Type(s) Cardinality Example Value
hasContentType File format, could be detected during the listing process and availability check. xsd:string or controlled vocabulary entry (URI) 1..1 “text/plain”, https://www.iana.org/assignments/media-types/application/json
hasLocalURL Endpoint that is used during the publishing process xsd:anyURI 1..1 https://raw.githubusercontent.com/examplefile.zip
hasEncryptedURL Contains the encrypted URL, which may be used to enable access control. xsd:string 1..1 7f9s79fu90s7f0s8fsfjsdpfjß8a002
hasEncryptionEndpoint Contains the endpoint responsible for URL decryption and access control xsd:anyURI 1..1 https://accesscontroller.yourname.com
hasFileIndex Index number, starting from 0 xsd:nonNegativeInteger 1..1 4
hasFileEncoding File encoding (e.g., UTF-8). xsd:string or controlled vocabulary entry (URI) 1..n “UTF-8”, http://gaia-x.eu/vocab/encoding/US-ASCII
hasContentLength Size of the file in bytes. [xsd:nonNegativeInteger] 1..n 378928719
hasChecksum Checksum of the file using your preferred format (i.e., MD5). Format is specified in hasChecksumType. xsd:string 1..n 25d422cc23b44c3bbd7a66c76d52af46
hasChecksumType Format of the provided checksum. Can vary according to server (i.e., Amazon vs. Azure) xsd:string 1..n md5

11.3.6.1 Resource

The mandatory attributes are:

Attribute Possible Datatype(s) Cardinality
location dct:location 1..1
jurisdiction dct:location 1..1
provided_by gax-participant:Participant 1..*

11.3.6.2 Interconnection Resource

An interconnection resource can consist of a physical medium resource, a connection resource or a route resource. One or multiple interconnection resources compose an interconnection service. The mandatory attributes (aka resource templates) of these are listed in separate tables below.

Attribute Description Possible Type(s) Cardinality Example Value
hasPhysicalMediumResource PhysicalMediumResource 0..1
hasConnectionResource ConnectionResource 0..1
hasRouteResource RouteResource 0..1
11.3.6.2.1 Physical Medium Resource

The Physical Medium Resource can be an individual interconnection resource. It has the following mandatory attributes:

Attribute Description Possible Type(s) Cardinality Example Value
hasPhysicalMediumResourceLocation references two locations (A and B) that require a connection (physical or virtual) xsd:string or dct:Location 2..2 (a point of presence, a facility, a data center, or an address)
hasPhysicalMediumResourceType the type of technology used for physical connection xsd:string or controlled vocabulary entry (URI) 1..1 “copper cable”, http://gaia-x.eu/vocab/medium/WiFi, “fiber”, “4G/5G”, …
11.3.6.2.2 Connection Resource

A Connection Resource (for example an Ethernet or Dense Wavelength Division Multiplexing (DWDM)) can also be the interconnection resource on its own. It has the following mandatory attributes:

Attribute Description Possible Type(s) Cardinality Example Value
hasConnectionPointA source reference ID xsd:string 1..1 MAC address, VLAN ID, …
hasConnectionPointZ destination reference ID xsd:string 1..1 MAC address, VLAN ID, …
hasBandwidth contractual bandwidth defined in the service level agreement (SLA) measure, e.g., in unit Gbps 1..1 1 Gbps, 10 Gbps, 100 Gbps, 400 Gbps
hasLatency contractual latency defined in the SLA. If not specified, then best effort is assumed. measure in the dimension of time, or the controlled vocabulary entry “best effort” 1..1 1 s, 10 ms, http://gaia-x.eu/vocab/value/BestEffort
hasAvailability contractual availability of provider services defined in the SLA agreement. If not specified, then best effort is assumed. measure in the pseudo-unit percent, or the controlled vocabulary entry “best effort” 1..1 99.9%, 99.99%, 99.999%,n/a
hasPacketLoss contractual packet loss defined in the SLA. If not specified, then best effort is assumed. measure in the pseudo-unit percent, or the controlled vocabulary entry “best effort” 1..1 1%, 10%, http://gaia-x.eu/vocab/value/BestEffort
notsupportedProtocols not supported protocols among used layers should be specified xsd:string 1..1 the spanning tree protocol is not supported
(optional) hasIntermediateConnectionPointsN intermediate connection/ interconnection point ID xsd:string 1..N MAC address, VLAN ID, …
(optional)hasConnectionType point-to-point, one-to-many, many-to-many, many-to-one xsd:string 1..1 ethernet unicast, multicast, broadcast support
11.3.6.2.2.1 Measure

A measure is a compound of a numeric value and a unit of measurement. A measure is typically not given an identifier and reused in multiple places, but written down locally, as the value of a single attribute. I.e., in the RDF data model, it is typically represented as a blank node. It has the following mandatory attributes:

Attribute Description Possible Type(s) Cardinality Example Value
hasValue the value of the measure any numeric datatype, e.g., xsd:float 1..1 100
hasUnit the unit of measurement xsd:string or controlled vocabulary entry (URI) 1..1 http://gaia-x.eu/vocab/units/Gbps

Controlled vocabularies of units support the definition of compound units from base units, the provision of conversion factors, etc. Vocabularies suitable for reuse include QUDT2.

11.3.6.2.3 Route Resource

A Route Resource can be an interconnection resource. It has the following mandatory attributes:

Attribute Description Possible Type(s) Cardinality Example Value
connected network autonomous system (AS) number (ASN) should be provided xsd:integer 1..1 200, 714
prefix set CIDR Provider Identifier [xsd:string] 1..1 10.1.1.1/24
origin node reference to connection points xsd:string 1..1 Node ID

  1. OWL 2 Web Ontology Language. Structural Specification and Functional-Style Syntax (Second Edition). W3C Recommendation 11 December 2012. http://www.w3.org/TR/2012/REC-owl2-syntax-20121211/ ↩

  2. http://www.qudt.org/ ↩