tjänstfunktionkedjor

Tjänstefunktionskedjor, often translated as service function chains or service function chaining (SFC), refers to a networking concept that allows for the flexible and dynamic steering of network traffic through a sequence of network functions. These network functions can be physical appliances or, more commonly today, virtualized network functions (VNFs) running on general-purpose hardware. The core idea is to create a programmable way to define and control the path that traffic takes through various services like firewalls, load balancers, intrusion detection systems, or deep packet inspection engines.

Instead of traffic always taking a fixed path, SFC enables the creation of service function chains, where a specific order of network functions is defined for a given traffic flow. This allows for granular control over how traffic is processed, enabling complex service policies and the rapid deployment of new services. For example, traffic from a specific user group might be directed through a firewall, then a VPN gateway, and finally to an application server, while traffic from another group might bypass some of these functions.

SFC is a key enabler for Network Functions Virtualization (NFV) and Software-Defined Networking (SDN). By decoupling network functions from dedicated hardware and allowing them to be instantiated and orchestrated as software, SFC provides the agility needed to adapt to changing network demands. It simplifies network management and allows for more efficient resource utilization, as services can be dynamically scaled and reconfigured as needed. The implementation of SFC typically involves a service function orchestrator and a service function forwarder.