N6-LAN: A new generation of data plane LAN service functions for 5G?

Use cases and services: 5G SA service types have become more diverse and complex; low latency applications, network slicing, edge applications, etc., will favor different N6-LAN service functions. For example, traffic steering will become more prevalent with user equipment session-driven and service-aware applications as network slicing becomes more widely available. Demand for content and resource optimization, as well as security service functions to safeguard and observe, remains high and is likely to continue. Additionally, load balancing and analytic functions will remain vital.

Support for multiple generations and technologies: The technology footprint has radically evolved between mobile generations. It now forms a mixed landscape of physical, virtualized and containerized network functions for many operators. The eagerness to embrace new technology and consolidation for efficiency also goes hand-in-hand with cost considerations and ease of management. This trend indicates that potential service function sharing or reuse across mobile generations (e.g., carrier-grade network address translation [CG-NAT] and some security protection appliances) might be applicable.

New protocols: The use of HTTP/3 (the latest version of Hypertext Transfer Protocol) and Quick UDP Internet Connections (QUIC) is growing fast across the internet, with both adding more efficient mechanisms to reduce latency and establish two-way communications. These new transport protocols benefit applications like real-time video streaming and conferencing, growing within 5G. The transition may require adjustments to existing data plane LAN components (e.g., CG-NAT functions) for transiting traffic and quality of experience video monitoring metrics, as QUIC is an encrypted transport protocol. Expected QUIC protocol use for multi-path routing via the access traffic steering, split and switching (ATSSS) network function (for policy-based routing across 3GPP and non-3GPP access) may also require changes.

Centralized: Many operator networks are still highly centralized, meaning the traditional service function "hub" is still relevant. This architecture is also advantageous where multiple gateways (i.e., user plane functions [UPFs] or packet gateways [PGWs]) will access similar SGi/N6-LAN functions and perhaps offer an interim transition from SGi-LAN to N6-LAN. However, transforming service functions toward a consolidated, single-hop containerized architecture should be the end goal to improve efficiency and reduce service function hops and management.

Distributed: Scenarios may exist where an operator's network contains a mix or high number of distributed UPFs to support different use cases or services (e.g., low latency edge applications, offload, tailored services, etc.). In these situations, colocating service functions at the same hosting location or hardware as the UPF offers multiple efficiencies, especially where microservices already support some or all service functions.

Integrated: Some UPF vendors have previously consolidated and incorporated selected value-added service functions offered on the data plane LAN into their products. Common function categories include DPI and optimization, although some bundle security of analytic capabilities as part of larger product offerings. This trend is likely to continue, but specialist vendor service functions (e.g., DDoS, malware protection, advanced analytics, etc.) will remain standalone.

Consolidation to increase management and cost efficiency (including potential reuse of existing 4G service functions).

Evolution of the traditional service function "hub" to support varying models (e.g., centralized, distributed and integrated).

Support for new capabilities and services in the data plane LAN (e.g., service-aware traffic steering, network slicing, new protocols, etc.).