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LSO Sonata APIs enable frictionless inter-carrier business operations.
Introducing LSO Sonata
A set of APIs based on the
LSO Reference Architecture for
Serviceability  | Ordering | Quoting
Billing assurance | Testing
Change management | Address Validation
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Technical Specification
IPS (Information Models)
Coming soon!
  • Develop with hackathons & implementation projects
  • Architect & enhance the info models & specs
  • Collaborate with the industry
MEF’s LSO (lifecycle service orchestration)
From subscriber intent to service realization, fully automated, within and between operators.

The MEF Lifecycle Service Orchestration (LSO) Architecture and Framework Specification – described in MEF Technical Specification 55 (MEF 55) - defines Management Interface Reference Points (IRPs) between the Customer, Service Provider (SP) and Partner domains. These are logical points of interaction between specific management entities. As shown below, LSO Sonata is the IRP between SP and Partner business applications. The IRP is described by a set of Interface Profiles (IPs), each one addressing a specific functional scope. The IPs supply the logical requirements for language specific (e.g. YANG, JSON, etc.) management data models and APIs.

LSO Reference Architecture

Looking at the figure above, consider the case of a large enterprise Customer with data centers and branch offices located around the world. This Customer is looking for a Service Provider to provide connectivity to all their locations. No single Service Provider has facilities to reach all customer locations. Typically, a Service Provider can reach some of the locations (on-net locations) but must work with a set of Partners to reach the other locations (off-net locations).

The interaction between Service Providers and Partners to deliver services to a single customer is predominantly manual involving people, emails, negotiations, etc., resulting in long time periods and costs to setup required connectivity. Accelerating these processes through automation provides cost savings and greater business value to the end customer. It also removes much of the error potential inherent in manual processes.

With hundreds of Service Providers and hundreds of Partners in the world, it would be prohibitively expensive to implement custom automation for each service provider – partner pair. MEF’s LSO Sonata APIs provide an industry standard so that a Service Provider (Buyer) may implement these APIs, and automatically work with all partners. Similarly, a Partner (Seller) may implement these APIs, enabling automation with all their partner Service Providers.

The MEF has a roadmap for LSO Sonata API development and publication involving four releases. Each LSO Sonata API is listed below together with its planned release number.

Application Programming Interface (API) Planned Release No.
Contract and Billing Management 4
Serviceability Management 1
Quote Management 1
Order Management 1 and 3
Inventory Management 1
Trouble Ticket Management 2
Invoice Management 4

a. Serviceability Management

  • Retrieve list of sites using filter criteria
  • Retrieve site by identifier
  • Retrieve address by identifier
  • Validate address
  • Create product offering qualification (POQ)
  • Retrieve list of POQs using filter criteria
  • Retrieve POQ by identifier
  • POQ notifications

b. Quote Management

  • Request quote
  • Retrieve list of quotes using filter criteria
  • Retrieve quote by identifier
  • Cancel or reject quote
  • Quote notifications

c. Order Management

  • Create order
  • Retrieve list of orders using filter criteria
  • Retrieve order by identifier
  • Change order
  • Cancel order
  • Disconnect order

d. Inventory Management

  • Retrieve list of products from inventory using filter criteria
  • Retrieve product from inventory by identifier

These APIs are said to be ‘product agnostic’ in that they are designed to work consistently regardless of the type of product being ordered (Optical access services, Ethernet Access Services, IP access Services, etc.). The details of the product being offered is contained in a payload carried over the API. For the first release, the format of this payload is being defined for the highest volume services, in this case, Access E-line products. Future releases will define the payload for other types of services.

The LSO Sonata APIs - Developer Release was made available to the public at MEF 18 in October 2018. This is a ’pre-standard’ version of the APIs and includes Technical Specifications (TS) that define the “Business Requirements and Use Cases” as well as Software Development Kits (SDKs) for each API. The SDKs include:

– Swagger Data Model: Developer can load in Swagger Data Model with Swagger Editor and Toolchain for frictionless development

– API Developer Guide: Describes REST resource models, provides sample JSON representations, defines associated state machines, and gives examples of operations

– Readme File: Introduces the developer to all the artifacts and how to use them

– Product Specifications: Access E-Line and UNI product payloads utilizing the polymorphic approach of API. This release is CE focused, though the APIs are product agnostic

LSO Sonata APIs - Developer Release, including all TS documents and SDKs available via the link:


The user is instructed to start at the README file which provides further instructions.

The purpose of providing a developer version of Release1 is to get feedback from the public, partners, and members of the MEF community before the official release, which is scheduled for Q1 2019.

Questions and Feedback should be directed to LSO-Sonata@mef.net. All artifacts included in the repository have line numbers. When referring to specific content in any of these artifacts, please quote the line numbers to which you are referring.

The LSO Sonata APIs have not yet been implemented in production due to their very recent release on 29 Oct 2018. There were however, 7 LSO Sonata API related “Proof-of-Concept (PoC)” demonstrations given at MEF 18. They provided valuable insight into how agile, assured, and orchestrated services can be delivered across automated, virtualized, and interconnected networks. In particular, the MEF 3.0 Fulfilment and Activation Implementation project showcased using Inter-Carrier LSO Sonata Pre-Order and Order APIs spanning 4 service provider domains.

There are two types of certification being defined: Buyer Certification, and Seller Certification.

Buyer Certification:

According to the LSO Reference Architecture, in general the “Buyer” is the Service Provider, Buyer certification is offered to Operators and/or Technology Vendors with solutions containing the MEF-defined SONATA interface and supporting the client-side of the MEF Release 1 of the LSO Sonata APIs.

Seller certification:

According to the LSO Reference Architecture, in general the “Seller” is the Partner provider. Seller certification is offered to Operators and/or Technology Vendors with solutions supporting MEF 3.0 Access E-Line services and the server-side of the MEF Release 1 of the LSO Sonata APIs.

Certification availability is targeted for Q1 2019 following publication of Release 1 of the LSO Sonata APIs.

Yes, LSO Sonata APIs – Developer Release was based on (and in some cases extended) the following TM Forum defined APIs:

  • TMF622 Product Ordering API
  • TMF637 Product Inventory API
  • TMF679 Product Offering Qualification API
  • TMF673 Geographic Address API
  • TMF674 Geographic Site API
  • TMF648 Quote API

Contribution to the LSO Sonata work is welcomed. Participation is restricted to active MEF member companies and their staff. Send an inquiry to LSO-Sonata@mef.net for more details.

LSO Sonata - The Start of a Journey
1st Priority – Order Management Automation
  • Reduce service set-up time
  • Deliver open standard API for inter-carrier connectivity
  • Based on TM Forum open API framework
Addressing Inter-Carrier connectivity
  • Interlude: MEF18 Survey: Rapid adjustments to existing services (90%)
  • Cantata: MEF18 Survey: Customers to scale bandwidth on demand (86%)
  • Blockchain: How do CSPs exchange information in a trustless environment?
  • Matching East-West with North-South capabilities
Offering Enhancements
  • Working with carriers and technology suppliers to further enhance the LSO Sonata offering.
LSO Sonata is a part of the LSO Reference Architecture