ITU standard defines management framework for cross-domain network slicing

The International Telecommunication Union has published a newly approved Recommendation ITU-T M.3375, a standard focused on managing cross-domain network slices in IMT-2020 networks and future mobile systems.

Network slicing allows operators to create logical networks with different performance characteristics over shared infrastructure. This is important for services with distinct requirements, such as enhanced mobile broadband, low-latency applications, and large-scale IoT deployments.

The difficulty is that end-to-end slices often span different parts of the network. Access, transport, and core networks may each be managed by separate systems. The recommendation addresses how these systems should coordinate slice creation, modification, performance monitoring, fault handling, and termination.

A key issue is mapping. Access and core networks use slice identifiers such as S-NSSAI, while transport networks use other identifiers, including VLAN IDs, IPv6 addresses, or UDP ports. ITU-T M.3375 defines how these identifiers should be managed so traffic reaches the correct slice subnet.

The standard also covers quality-of-service mapping. It explains how QoS parameters used in mobile networks can be mapped to transport network fields such as DSCP and 802.1p, helping maintain consistent packet treatment across domains.

The recommendation sets out roles for management functions, including the communication service management function, network slice management function, and network slice subnet management functions for access, transport, and core networks.

Its practical value lies in operational coordination. Without agreed procedures for identifier mapping, QoS translation, and lifecycle management, network slicing risks becoming difficult to scale across multi-domain mobile networks.