DSNA&ENAV
DSNA: the French air navigation service provider
ENAV; the Italian air navigation service provider
CCS SSRCodeManagement 2.0.0
Abstract
This Service is part of Coflight Cloud Services (CCS), which are primarily designed to support the Virtual Centre concept. As such, these CCS Services support the interactions between the CCS ATM Data Service Provider (ADSP) and Virtual Centre Air Traffic Service Units (ATSUs). The CCS SSRCodeManagement service is consistent with the other CCS services. It addresses the assignment of SSR codes to eligible flights and release of SSR codes assigned to flights when requested to do so. Normally, to reduce controller workload, the assignment and release processes are triggered automatically by a timer or event. However, if the automatic process fails, operations are provided for controllers and other authorised users, e.g. FDO, to manually request the assignment or release of a code. This version of the service is intended to be used in 'test mission', which aims at providing services and support to the Customer(s) to enable them to test any version of their ATM system during development.
Service retired from 20/03/2023
Service Type
SWIM_COMPLIANT
Life Cycle
Business Activity Type
INFORMATION_MANAGEMENT
Intended Consumer
CIVIL_AIR_NAVIGATION_SERVICE_PROVIDER
Information Exchange Category
FLIGHT_INFORMATION_EXCHANGE
In-Operation Date
24-Jun-2022
Provider
Provider Type
CIVIL_AIR_NAVIGATION_SERVICE_PROVIDER
Point of Contact
General
Operational Needs
CCS SSRCodeManagement Service addresses the assignment of SSR codes to eligible flights and release of SSR codes assigned to flights.
It addresses operations such as:
- releaseSSRCode,
- requestSSRCode,
- setModeSEligible.
Functionality
To release an SSRCode assigned to a flight
To request an assigned SSRCode for a flight
To set a flight as mode S eligible
Access and Use
IPR
In accordance with their internal contractual rules on IPRs, DSNA, ENAV and skyguide retain exclusive ownership of the information contained in this document, which is to be deemed as foreground of the Coflight Cloud Services project (aiming at delivering remote flight data processing).
Access to the Service
This service is provided to Service Consumers under a contractual basis signed between the CCS Service Provider and the Service Consumer.
If the service consumer also consumes other CCS services, this Service shall be consumed simultaneously with the other CCS SWIM Services that are part of the contractual agreement between the service consumer and CCS service provider.
This service will be updated to be as much as possible in line with the Service Definition produced by SESAR Virtual Centre activities
Both the SWIM Service Description documents / Protobuf files and the CCS Services are versioned.
The version assigned to SSDs and to Protobuf files is composed by four digits in the form x.y.z.w.
New releases are numbered according to the following rule (compared to the previous version):
- w increased by one: means that some content that could be ignored by the developers changed and the changes do not affect the protobuf files generation. For example, changes in the comments or in the descriptions of services, fields and data structures.
- z increased by one: means that some content is changed by adding (but not changing or removing) some messages and/or data types. The generated protobuf files are expected to be an extension of the previous one and as result they are backward compatible.
- y increased by one: means that the file is changed by changing or removing some operations. The generated protobuf files are not expected to be compatible with the previous one.
- x increased by one: means that the file contains a new baseline. Major changes are expected to be present.
The service version is composed by 3 digits a.b.c assigned according to the following rule:
- a could be 0,1,2 depending on the status of the service with respect to the SWIM registration phase:
0: before the service application (as candidate)
1: if candidate
2: if compliant
- b Increments if major changes have been done with respect to the previous version (modify/remove). No backward compatibility.
- c Increments if minor changes have been done with respect to the previous version (addition/description modified). Full backward compatibility.
Services management review are regularly organized with CCS customers to monitor the usability of the services and the KPI related to the quality of service described in the SLA.
The interface of CCS business services is accessible from outside DSNA premises through Internet using IPV4. An IPSEC link (IKE v1 or IKE v2) is used between CCS provider and CCS customer terminal network equipment.
The CCS provider acts as a certificate authority to provide and validate X.509 certificates. Before service operation, a package including X509 certificate and private key, will be delivered to the customer using the PKCS#12 archive file format.
Mutual authentication with X509 certificates is used between the AMQP broker and its client. Prior to any exchanges of AMQP Messages, the CCS customer shall establish with CCS Provider a TLS session using TLS 1.2 version.
- CCS customer shall provide its certificates when establishing the connection. The certificates shall be valid (nor corrupted, nor revoked). The certificates of the CCS customer allow its identification for the use of the different CCS services (CCS business services at lower level).
- The CCS provider transmit its complete certificate during the connection phase and allow OCSP stapling to allow the CCS customer to check if it is valid or not.
- For the cryptographic algorithms, the authorized cipher suites must be agreed between the CCS provider and the customer based on the standards.
As an ATSU, the CCS business services customer, once identified, has access to all CCS services.
In the case of a Customer that would fail to authenticate 3 times in less than 3 minutes, the IP address would be ban and has to trigger the incident management procedure.
Quality of Service
The service level objectives regarding the availability, response time, throughput and recoverability of CCS Services depend on the purpose (mission) for which the Customer intend to use them (e.g. integration, test, training, operational purpose).
These service level objectives are therefore negotiated with the Customers, based on their safety analysis, and are detailed in the specific Service Level Agreement established with each CCS Customer.
The minimum Bandwidth required to consume CCS services (hypothesis for the technical integration service of 300 simultaneous flight managed by the system) is 10MB/s.
Customer ATSU shall restrict the overall rate of requests to a maximum of 720 request/minutes. The detailed rate limitation per services is detailed in the associated swim service description of each service.
Abbreviations
Area Control Centre
ATM Data Service Provider
ATM Information Reference Model
Advanced Message Queuing Protocol
Air Navigation Service Provider
Air Traffic Control
Air Traffic Control Services
Air Traffic Management
Air Traffic Service Unit
Coflight Cloud Services
Controller Working Position
Direction des Services de la Navigation A0xC3 0xA9rienne (French ANSP)
Ente Nazionale Assistenza al Volo (Italian ANSP)
Flight Data Operator
Flight Data Processing System
International Civil Aviation Organization
Identifier
Internet Key Exchange
Internet Protocol
Internet Protocol Security protocol
Joint Undertaking
Key Performance Indicator
MegaByte
Network Time Protocol
Online Certificate Status Protocol
Public Key Cryptography Standards
Service Definition Document
Single European Sky Air Traffic Management Research
System Flight Plan
Service Level Agreement
SWIM Service Description
Synchronous Serial Interface
Secondary Surveillance Radar
System Wide Information Management
Transfer Control Protocol
Technical Infrastructure
Transport Level Security
Coordinated Universal Time
Information
Information Definition
For the exchanged data model, please refer to the SWIM Service Description document (sections 2.1 and 2.2)
Data Structures
Schema Language
Protocol buffer
Reference
CCS_ssrCodeManagement.proto 1.0.0.2
Schema Language
Protocol buffer
Reference
CCS_ssrCodeManagement.proto 1.0.0.2
Schema Language
Protocol buffer
Reference
CCS_ssrCodeManagement.proto 1.0.0.2
Technical
Security Mechanism
Mutual authentication with X509 certificates is used between the AMQP broker and its client established within a TLS session
TLS 1.2 is used to provide confidentiality and integrity at transport layer.
IPsec is used to provide confidentiality, authentication and integrity at network (internet) layer
Technical Constraint
CCS provider and CCS customer use the date and time for the operation of each service and they must be able to date the traces and the information passed to the SSI log collector.
NTP is the standard solution to synchronize time accurately. So, CCS Provider and CCS Customer should use, each of them, at least one NTP server (stratum N), integrated in a NTP network containing a stratum 0 reference time clock.
Each services interface of the CCS business services relies on the concept of AMQP queues and topics.
- The CCS customer shall use an implementation of the AMQP 1.0 specification to connect to the CCS provider AMQP 1.0 endpoint.
- The CCS provider endpoint is an AMQP 1.0 broker managing queue and topics.
The message payloads are encoded following a protobuf format.
The message exchange patterns used by the CCS services are request/reply and publish/subscribe. The CCS customer acts as requester and subscriber. The CCS provider acts as responder and publisher.
Concerning publish-subscribe, the CCS customer subscribes to a CCS distribution service by directly listening to an appropriate AMQP topic, which name follows the CCS derivation rules.
The subscription to CCS Distribution Services is not performed via subscription operations, but by connecting to the appropriate AMQP Topic described in the .protobuf files as topic://..
The subscribers can filter the messages they want to receive by using the filter parameters defined for each subscription operation.
Please note that, after subscribing to a CCS Distribution Service, the current repository of messages needs to be obtained from CCS via the get operation defined for each CCS Distribution Service (see "Subscription" section of the distribution operation of the service).
N.B:
- If the CCS platform restarts while the Customer is connected to the AMQP Broker, the current repository of messages is published again.
- The acknowledgement that a Customer receives to his request ("RequestReport") may be received after the data distribution that this request has triggered, as these two messages are managed asynchronously by AMQP Queues and Topics
Concerning request-reply the CCS customer sends a request by sending a message to an appropriate AMQP queue, which name follows the CCS derivation rules, to make a request. The request message contains the name of the queue into the CCS customer listens and in which the reply from the CCS provider is expected.
The Customer is the one that initiates the TCP connection and in case of a Network / Connection failure, it is the responsibility of the CCS customer to try to reconnect regularly.
The AMQP broker creates the physical resources associated with a destination (queue, topic) on demand when messages are actually sent to them.
Permissions on queues and topics (read/write access) are granted based on intended usage. The CCS customer will have:
- Write access on the request queue
- Read access on the reply queue
- Read access on the topic for distribution service
Interfaces
This Service Interface exposes the set of basic operations needed for SSR Code Management.
Operations
The operation allows to release an assigned SSR code if it is not used for correlation purpose.
Due to the limited number of Mode 3/A SSR codes it is necessary to release assigned codes back into the pool of available codes when possible. Normally this would be handled automatically with the Flight Data Manager or other service monitoring the status of a flight and requesting the release of a code when a flight lands, leaves the Area of Responsibility of an ATSU or is cancelled..
Synchronous
SYNCHRONOUS
TI Protocol Methods
transfer
Operation Message
Processing Consideration
The operation allows to manually assign a code given in the input, or to request an automatic code assignment.
The manual assignment is allowed if there is no code assigned, as well as if there is one already assigned to the flight, in order to modify it.
If ssrCode is provided in the input (i.e. manual assignment), the operation allows changing either the code assigned to the segment given in the input, the code assigned to the previous segment, or the one assigned to the next.
- for the assignment of the code to the given segment: If the controlled SFPL internal segment is correlated on the current assigned SSR code, or if the flight is not yet correlated and previousSSRCode is empty, the system shall push the currently assigned SSR code in the previousSSRCode and the new assigned one in the assignedSSRCode. Otherwise the system shall overwrite the currently assigned SSR code by the new one.
- for the assignment of the code to the previous or next segment: the input is accepted if the code to modify is not currently used for correlation purpose.
Synchronous
SYNCHRONOUS
TI Protocol Methods
transfer
Operation Message
Processing Consideration
Endpoints
Interface Binding Description Overview
Information is exchanged in Protobuf format. Protocol buffers or Protobuf are Google's language-neutral, platform-neutral, extensible mechanism for serializing structured data similar to XML, but smaller, faster, and simpler.
Behaviour
The detailed behavior of the service is provided in each operation dedicated section
This Service Interface exposes the set of operations related to SSR Code Management that are not necessarily required to achieve a usual/basic interoperability level.
Operations
The operation allows to reset the isEligibleForModeSCode indicator (i.e. change it from TRUE to FALSE) or, if manually reset, to enable again its automatic reassessment (i.e. enable its automatic change from FALSE to TRUE, if previously manually changed from TRUE to FALSE).
The setModeSEligible attribute is ignored by CCS.
When the system will have to automatically assign a SSR code to the flight, the system will take this status (indicator set or not) into account to determine the proper code to use (discrete or conspicuity).
By default, automatic reassessment is allowed.
On reset of the "Eligible for Mode S Code" indicator in the SFPL, the system shall:
- trigger a new discrete SSR code automatic assignment to the controlled SFPL internal segments that had the conspicuity code automatically assigned and are not in left status, if any, and
- store the conspicuity code in the PSSR of these internal segments, if any, and
- remove the Mode S address stored in the SFPL, if the SFPL was correlated on the conspicuity code.
- disable the automatic reassessment of the indicator.
If automatic reassessment is allowed, the indicator is TRUE if :
- the flight is Mode S equipped
- the entire remaining route is included in a Mode S declared Airspace
- the flight belongs to a Mode S flagged directional flow.
For an inbound flight, if the SSR code received from the upstream segment is the Mode S conspicuity code, the system forces the Mode S capability of the flight and considers it as a Mode S flight..
Synchronous
SYNCHRONOUS
TI Protocol Methods
transfer
Operation Message
Processing Consideration
Endpoints
Url
For security reasons, the addresses will be communicated only to Customers
Addressable Resource
Name of the queue
Interface Binding Description Overview
Information is exchanged in Protobuf format. Protocol buffers or Protobuf are Google's language-neutral, platform-neutral, extensible mechanism for serializing structured data similar to XML, but smaller, faster, and simpler.
Behaviour
The detailed behavior of the service is provided in each operation dedicated section
References
Service Documents
AIRM traceability for CCS SSR Code Management service payload
Reference
https://confluenceccs.se-dmf.eu/display/CDFSR/CCS+SSR+Code+Management+Service
Note: to request access to Confluence, please refer to the point of contact section
Note: to request access to Confluence, please refer to the point of contact section
Validation evidence for CCS SSR Code Management service
Reference
https://confluenceccs.se-dmf.eu/display/CDFSR/CCS+SSR+Code+Management+Service
Note: to request access to Confluence, please refer to the point of contact section
Note: to request access to Confluence, please refer to the point of contact section
Protobuf files describing the exchanged information
Reference
https://confluenceccs.se-dmf.eu/display/CDFSR/CCS+SSR+Code+Management+Service
Protobuf file describing the exchanged information common to two or more CCS Services
Reference
https://confluenceccs.se-dmf.eu/display/CDFSR/CCS+SSR+Code+Management+Service
Protobuf file describing the metadata used by the CCS Services
Reference
https://confluenceccs.se-dmf.eu/display/CDFSR/CCS+SSR+Code+Management+Service
Complete service specification
Reference
https://confluenceccs.se-dmf.eu/display/CDFSR/CCS+SSR+Code+Management+Service
Document that includes the list of all applicable error messages for CCS services
Reference
https://confluenceccs.se-dmf.eu/display/CDFSR/Applicable+Documents
Implemented Standards
This specification contains requirements for describing information services in the context ofInitial System Wide Information Management (iSWIM). The requirements prescribe the minimum set of elements a service descriptionhas to contain
This specification contains requirements forinformation definitions, meaning the formal descriptions of exchanged information, in the context of Initial System Wide Information Management (iSWIM). This contributes to semantic interoperability of information.
This specification contains requirements for system interfaces (e.g. protocols) and for IT infrastructure capabilities required to enable a reliable, secure and efficient exchange of information in the context of Initial System Wide Information Management (iSWIM).This contributes to technical interoperability
Revision Save Date
Mon, 03/25/2024 - 23:20
The service description has currently reached the "PUBLISHED" status.
Schema version
v2