[Guest Post] Standardizing Service Chaining Models for Next-generation Service Provider Architectures

By Nicolas Bouthors*, Distinguished Technologist, Qosmos

With intense competition in the communications industry, service providers are looking for ways to offer new services faster and more cost-effectively. Dynamic service chaining allows you to do just that. With application-aware service chaining, you can quickly and efficiently create and deliver new, composite services by routing network flows through multiple, linked service functions (SFs). Three industry organizations have proposed complementary standards for service chaining that include Deep Packet Inspection (DPI) integration because it is considered critical in making the models application-aware.

The Internet Engineering Task Force (IETF) is developing a service function chaining (SFC) architecture that uses network flow classification to route traffic between service functions. Incoming network packets are sent to a service classifier, which attaches a metadata header to each packet and then forwards it to the appropriate set of service functions for processing. DPI technologies are used to enhance the capabilities of the service classifier, allowing it to identify the application in use and collect and format detailed metadata in a standard way.
   

The European Telecommunications Standards Institute (ETSI) model is based on a generalized service architecture that uses network forwarding graphs to route traffic between virtual network functions (VNFs). Pre-defined virtual links connect service functions into chains. Network traffic is routed along service chains based on forwarding paths and policies. DPI provides the information needed to make service functions application-aware, and ETSI has defined the DPI module as a reusable virtual network function component (VNFC) within their architecture.
   

Finally, the Open Networking Foundation (ONF) has proposed a software-defined networking (SDN) service chaining framework that uses an OpenFlow-based programmable switch and network forwarding graph to direct traffic to the appropriate service functions. DPI provides the application information needed to route traffic according to SDN rules and policies.

The three organizations are actively working together and with the larger open source community to merge their projects into a complete, common service chaining model, as shown in Figure 1. ETSI and ONF are collaborating on network functions virtualization (NFV) and SDN integration projects to create proofs of concept (PoCs) and reference implementations. The ONF model leverages the OpenStack Networking (Neutron) Group-based Policy declarative approach to create communication contracts between groups of servers providing network services. And, more solidified specifications and reference implementations are planned for release in 2015 as each organization works toward key milestones. 

Figure 1: The combined IETF, ETSI, and ONF service chaining model.

In the above diagram, the DPI is supplied in the form a service aware module (in this case provided by Qosmos) which acts as a service classifier by providing real-time application awareness to virtual switches. As one of the leading experts in DPI technologies, Qosmos is active in all the IETF, ETSI and ONF initiatives for a common service chaining model, providing essential insight into DPI in order to speed development of the future standards and architectures and deployment of the next generation networks. The company also continues to work with standards organizations toward the vision of end-to-end application awareness throughout the next-generation service provider architecture, from orchestrator to data plane.

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*Nicolas has spent many years in the telecommunications and information systems field. He was instrumental in creating Hewlett-Packard’s OpenCall business. As the R&D manager of Inovatel, the advanced research organization of SFR, Nicolas led several innovative projects highlighting the impact of internet technologies on Mobile Operators. Nicolas holds several patents relating to Mobile Data Charging.

Nicolas joined Qosmos to focus on emerging SDN and NFV architectures. He contributes to IETF SFC, ONF and ETSI NFV initiatives to add Layer 4 to Layer 7 capabilities within global SDN/NFV architectures. 

Nicolas holds an engineering degree from the French schools Ecole Polytechnique and Les Mines de Paris.