6.35 Service Function Chaining

22.2613GPPRelease 18Service requirements for the 5G systemTS

6.35.1 Introduction

In order to support enhancement of service function chaining for 5G networks beyond the requirements for FMSS in TS 22.101, the network operator defines service function chaining policies for service function chaining to steer the traffic associated to the application and its users on per UE basis to appropriate ordered service functions.

A service function chain for 5G networks contains service functions such as firewall functions, NAT, antimalware, parental control, DDoS protection, TCP proxies, load balancers, KPI monitoring, and video optimization, etc.

NOTE: these are non-exhaustive examples of service functions. Other service functions can be provided by an operator.

6.35.2 General Requirements

The following requirements apply for supporting enhancement of service function chaining for 5G networks:

– The network operator shall be able to define and modify service function chaining policies for steering traffic on per application per UE basis through required service function chaining with ordered service functions to improve the user’s QoE.

– Service functions chaining policies shall be able to distinguish between upstream and downstream traffic.

– The coexistence of traffic with and without service function chaining shall be supported.

– Service function chaining shall provide suitable means for authorized third parties to request a chain of service functions provided by the network operator based on operator’s service function chaining policies.

– In case of roaming, the HPLMN shall be able to apply traffic steering policies and service function chaining polices for home routed traffic.

– In case of roaming with local breakout, the HPLMN shall be able to provide the traffic steering policies and service function chaining policies to the VPLMN providing local breakout with support of service function chaining.

– Service function chaining shall support deployments where the Hosted Services are provided by the operator and deployments where the Hosted Services are provided by a third party.

6.35.3 Service Function Management

– The service function management shall allow the operator to create, modify, and delete a service function based on operator’s service function chaining policies.

– The service function management shall allow the operator to create, configure, and control a chain of service functions per application and its users on per UE basis based on operator’s policy or request from third parties.

– The service function management shall be able to manage service function chaining for deployments where the Hosted Services are provided by the operator and for deployments where the Hosted Services are provided by a third party.