CSC

Communication Service Customer

Services →
Introduced in Rel-5 Also in: Services, Core Network, Security

CSC is the 3GPP management entity that purchases, consumes, and manages communication services from a network operator or service provider.

Category
Services
Introduced
Rel-5
Where
Management
Also touches
3 segments
Specifications
21 specs
CSC Description Purpose Detected Changes Specifications

Description

The Communication Service Customer (CSC) is a functional role defined within the 3GPP management architecture, specifically in the context of the Management and Orchestration (MANO) framework and network slicing. It represents the organizational entity (which could be an enterprise, a vertical industry player, a virtual operator, or even another service provider) that has a commercial agreement with a Communication Service Provider (CSP) to consume one or more communication services. The CSC is not the end-user device but the administrative and business entity responsible for the service relationship.

Architecturally, the CSC interacts with the CSP's management systems through standardized reference points, primarily the Consumer-facing Service Interface (CnF). Through this interface, the CSC can request services, such as the creation of a network slice instance, modify service parameters, monitor service performance, and receive fault and performance reports. The CSC's domain includes its own management systems (CSC Management System) which may integrate with the CSP's Business Support Systems (BSS) and Operations Support Systems (OSS). This separation allows the CSP to expose a controlled set of management capabilities to the customer, enabling self-service and automation.

The role of the CSC is central to the network slicing paradigm defined from 3GPP Release 15 onwards. When a CSC (e.g., an automotive company) requires a dedicated network slice for connected car services, it submits a service request via the CnF. This request, containing the Network Slice Service Profile, triggers the CSP's orchestration systems to instantiate the necessary network functions across the RAN, transport, and core network to fulfill the service-level agreement (SLA). The CSC then receives continuous insight into the slice's performance, including key performance indicators (KPIs) like latency, throughput, and availability, allowing for proactive management of their application's quality of experience.

Key components in the CSC ecosystem include the CSC Management System, which formulates service requests and consumes service assurance data, and the Service Management Function (SMF) within the CSP's domain that handles these requests. The relationship is governed by a Service Level Agreement (SLA) that defines technical performance targets, business terms, and reporting obligations. The CSC concept enables a clear demarcation between the provider's network management responsibilities and the customer's service management responsibilities, which is essential for complex, SLA-driven 5G and beyond services.

Purpose & Motivation

The CSC concept was introduced to formalize and standardize the business-to-business (B2B) and customer-to-provider relationship in telecommunication services, particularly as networks evolved to support diverse vertical industries with 5G. Prior to its formal definition, service management interfaces were often proprietary, limiting automation and hindering the scalable onboarding of enterprise customers. The CSC model addresses the need for a standardized, automated, and programmable interface through which customers can directly interact with the provider's network capabilities.

Historically, enterprise services were provisioned through manual, ticket-based processes with limited customer visibility into network performance. The shift towards network virtualization, cloud-native principles, and network slicing demanded a more dynamic, API-driven approach. The CSC role, along with the CnF interface, was created to solve this by enabling zero-touch service management. It allows vertical customers (in manufacturing, healthcare, logistics, etc.) to order, configure, and monitor their dedicated network services (slices) on-demand, much like consuming cloud computing resources. This is a fundamental change from the traditional monolithic, one-size-fits-all network service model.

Furthermore, the CSC framework supports the monetization of 5G networks by providing the necessary management architecture for Network-as-a-Service (NaaS) business models. It allows Communication Service Providers to expose network capabilities as manageable, billable services with clear ownership and accountability boundaries. This empowers enterprises to innovate by integrating guaranteed network performance directly into their operational technology and applications, driving the digital transformation of industries.

Release Timeline

Detected Changes Across Releases

from 3GPP Change Requests

Specific changes extracted from the „Change history“ tables of 3GPP specifications (3 CRs across 2 releases). Complements the general historical overview above with the evidence-based evolution of this function.

Rel-18 2 changes

In Release 18, corrections and clarifications were made to specific CSC reference point interfaces, including technical corrections to the SIP interface for reference points CSC-7, CSC-19, and CSC-20. Additionally, general corrections were applied to a reference point definition within the CSC functional model.

  • Corrections to reference point CSC-16 TS 23.280CR0348
  • SIP interface corrections for reference points CSC-7, CSC-19, CSC-20 TS 23.280CR0349
Rel-20 1 change

In Release 20, the CSC function was enhanced by incorporating additional interactions for the Location Management Service (LMS) and Mission Critical (MC) Service Server, as detailed in the revised CSC-15. This update specifically expanded the application plane interactions, where the CSC-7 reference point's utilization of the SIP-3 reference point was explicitly defined for scenarios involving multiple SIP cores between group management servers. These refinements provided greater architectural flexibility and clarity for server interactions within the Mission Critical Push-To-Talk (MCPTT) framework.

  • Revised CSC-15: Incorporating Additional LMS and MC Service Server Interactions TS 23.280CR0671

Explore further

Broader topics and technologies where CSC plays a role.

Defining Specifications

3GPP specifications that define or reference CSC, with the latest known release. Sourced from the 3GPP document catalog — see methodology.

SpecificationTitleRelease
TS 23.179 vd50 MCPTT Functional Architecture Rel-13
TS 23.280 vk10 Common Architecture for Mission Critical Services Rel-20
TS 25.223 vj00 UTRA Physical Layer TDD Spreading & Modulation Rel-19
TR 26.941 vj01 5G Media Slicing Extensions Rel-19
TS 28.530 vj00 Network Slicing Concepts & Requirements Rel-19
TS 28.531 vk00 Management and Orchestration Rel-20
TS 28.535 vj00 Closed Control Loop Assurance Management Rel-19
TS 28.536 vj20 Management services for communication service assurance Rel-19
TS 28.557 vj00 Management of Non-Public Networks (NPN) Rel-19
TS 28.805 vg10 Management of Communication Services in 5G Rel-16
TR 28.812 vh10 Study on Intent Driven Management Services Rel-17
TR 28.828 vi00 Charging Aspects for Non-Public Networks Rel-18
TR 28.836 vi00 Technical Report on Intent Driven Management Rel-18
TR 28.843 vi10 Technical Report on Charging Aspects for Vertical Scenarios Rel-18
TR 32.847 vi00 Technical Report Rel-18
TS 33.127 vj50 Lawful Interception Architecture and Functions Rel-19
TS 33.128 vj50 3GPP TS 33.128: Lawful Interception Protocols Rel-19
TS 33.179 vdc0 MCPTT Security Architecture and Procedures Rel-13
TS 33.180 vk00 Security of Mission Critical (MC) Service Rel-20
TS 33.879 vd10 MCPTT Security Study Rel-13
TS 33.880 vf10 Security Study for Enhanced Mission Critical Services Rel-15
Patrick Zandl

About the author: Patrick Zandl (b. 1974)

Telecommunications specialist, technology journalist (founder of the Mobil server), and developer who has been running since 2025 — the largest Czech-language resource on AI-assisted programming. Formerly Chief Wizard Architect at Prusa3D and head of development for Turris at CZ.NIC; currently a consultant and instructor on AI implementation in companies.