Overview of the role of the Spine Directory Services (SDS) within GP Connect

1. Common SDS requirements

1.1 Unique ASID per organisation using a system

Every system using GP Connect SHALL have a unique ASID for each organisation using it, so the same system deployed into three organisations would be represented by three unique ASIDs.

Conversely, if two different consumer systems are deployed in a single organisation, two unique ASIDs would be required.

Shared systems such as a Regional portal which are provisioned by a single organisation, but used by other organisations, SHALL have a unique ASID per organisation using the system.

1.2 Do not reuse GP Connect ASIDs and Party Keys for central Spine services

New GP Connect ASIDs and Party Keys must be registered for use with GP Connect; existing ASIDs and Party Keys for central Spine services SHALL NOT be reused.

1.3 Maximum of one GP Connect provider system per organisation

Only one GP Connect provider system can be registered in SDS for an organisation; multiple provider systems for the same organisation are NOT supported.

1.4 Multiple GP Connect consumer systems per organisation to be supported

Only one consumer system per organisation is supported currently (as of March 2019), however once all providers and consumers have migrated to version 1.2.3 of the GP Connect API specification - specifically uplifting their SDS queries - more than one will be supported.

Examples:

  • An urgent care centre with an Access Record HTML consumer system, and a seperate Appointments consumer system
  • A GP practice using a GP system with GP Connect enabled as provider and consumer, and a seperate regional portal system with access to Access Record HTML as a consumer

2. Consumer specific SDS requirements

2.1 Use seperate MHS and AS endpoint records; not CMA style endpoints

Consumers MUST NOT register entries in SDS as CMA (combined MHS and AS) style endpoints. This is because the MHS record for a consumer system MUST NOT have GP Connect interactions on the endpoint, whereas the AS record MUST - creating a CMA style endpoint will not allow this distinction to be made.

2.2 GP Connect Interactions IDs on AS records only

GP Connect interaction IDs on AS records indicate the system is permitted to send GP Connect messages as a consumer.

GP Connect interaction IDs on an MHS record indicate the Messaging Handling Server is a GP Connect provider, therefore this SHALL NOT be done for consumer (only) systems.

2.3 Shared Party Key may be used depending on topology

Consumer systems MAY use a single GP Connect Party Key for multiple organisations, if they connect to Spine via a single shared message handling server.

However, as per 1.1 Unique ASID per system used by an organisation each consumer organisation SHALL have it’s own unique ASID.

Please see System topologies for more information.


3. Provider specific SDS requirements

3.1 Use CMA type endpoints

In order to allow for practice specific routing using endpoint, all systems SHALL have a unique GP Connect Party Key and ASID per practice, registered in SDS as a “CMA type” endpoint.

A CMA type endpoint refers to an endpoint which is a combined MHS system and accredited system endpoint. There will be a 1-1 mapping between an Accredited System (uniquely identified by an ASID) record and a Message Handling System (MHS) record. A single MHS record SHALL be associated with a given ASID and interaction ID.

3.2 GP Connect Interaction IDs on MHS and AS records

GP Connect Interaction IDs SHALL be registered on both MHS and AS records (using a CMA type endpoint).

GP Connect interaction IDs on an MHS record indicate the Messaging Handling Server is a GP Connect provider.

3.3 Provider systems who are also consumers use the same ASID and Party Key for both roles

Provider systems which also offer consumer functionality SHALL use the same GP Connect Party Key and ASID for both provider and consumer roles.

3.4 Format of Service Root URL

The Service Root URL for a given ASID SHALL be defined in the nhsMhsEndPoint attribute of the MHS record (i.e. the LDAP object of type nhsMhs). This URL SHALL be in the format described in Service Root URL versioning guidance.

As described in the API versioning guidance, the practice’s ODS code SHALL be placed in the FHIR server root URL, and this SHALL match the value in the nhsidcode elements on the MHS and associated AS records. ODS codes which refer to clinical systems as a single entity SHALL NOT be used to provide routing. Practice specific ODS codes SHALL be used for routing purposes in the FHIR Server Root URL found in the nhsMhsEndPoint attribute of the MHS record.

3.5 nhsMhsEndPoint attribute SHALL contain the FHIR service root URL only

The nhsMhsEndPoint attribute in the MHS record SHALL contain the FHIR Service Root URL. It is the responsibility of the consuming system to construct the FHIR operation or RESTful resource request which will be postfixed to this base URL.

An example of a FHIR server root URL for a Retrieve a patient’s structured record interaction at practice GP0001 is:

https://provider.thirdparty.nhs.uk/GP0001/STU3/1

Note that the /Patient/$gpc.getstructuredrecord is NOT added.

In line with this, provider systems SHOULD perform checks that the FHIR request received is a reasonable means to request the resource in view given the specified interaction.

3.6 FHIR service root URLs associated with a given product set SHALL use same FHIR version

Where a provider moves in future to a later version of FHIR, it will be necessary to define a new product set to accommodate the set of interactions provided by this. FHIR server root URLs defined for a specific product set SHALL all reference the same FHIR version. This ensures that FHIR resources references returned in FHIR responses are locally resolvable.

For example, all interactions associated with the Appointment Management capability pack in a given product set must refer to the same FHIR server, so that the resource references for ‘Read Appointment’ and ‘Amend’ appointment would be locally resolvable to the same resource on the same FHIR Server.

3.7 Acceptable use of ASID information in HTTP Headers

Source and destination ASID information is passed to the provider system from the Spine Security Proxy. Providers SHALL use this information for audit and debugging purposes only, and SHALL NOT use these headers to perform routing or lookups.

It is the responsibility of the SSP to perform lookups to determine consumer accreditation status. Routing shall be carried out as described above through practice-specific ODS codes present in the FHIR server root URL.


SDS terminology

LDAP Lightweight Directory Access Protocol. A protocol for accessing directory services
SDS Spine Directory Service. A directory held in Spine containing accredited Spine system identifiers, endpoints, and other reference information; accessed by LDAP
MHS Message handling server. Middleware that handles messaging to/from Spine. See System topologies for more information
MHS record LDAP object of type nhsMhs in SDS, uniquely identified by Party key, and representing a message handling server
Party key The unique identifier of an MHS record
AS record LDAP object of type nhsAs in SDS, uniquely identifier by ASID, and representing a Spine connected system deployed at an organisation
ASID Accredited system identifier. A unique identifier allocated to a system at an organisation for connection to Spine. Uniquely identifies an AS record in SDS
CMA type endpoint A way of registering MHS and AS record for a system at a single organisation which creates a Party Key and ASID for use only at that organisation
MHS type endpoint An endpoint registered with Spine for use with multiple systems via an MHS. Each system has its own ASID
Tags: integration