Latency control in service chaining using P4-based data plane programmability

Service chaining is becoming one of the most considered service deployment frameworks in context Network Function Virtualization (NFV) edge and data center environments, conveniently supported by automatic connectivity configurations offered Software Defined Networking (SDN). Current research on topic focusing how to guarantee Quality (QoS) terms guaranteed end-to-end latency for time critical services. Indeed, issues may depend intra-server virtualization inefficiencies, leading Virtual (VNF) delivery delays, or congestion events occurring at intermediate network elements connecting VNFs. Latency control requires stateful information such as flow delay measurements a per-packet level, typically not available traditional SDN switches inside VNF. This paper proposes adoption plane programmability exploiting P4 language presents two pipeline solutions, suitable both intra-rack inter-rack chain deployments, automatically check path experienced selected high priority flows, also resorting recent in-band telemetry applications. The programmable pipelines enforce proactive in-network functions, change drop actions, order bound SFC segment delivery, including proposed solutions are implemented evaluated testbed employing software showing their effectiveness guaranteeing configured latency, limited effort additional processing switch. evaluation carried out using reference switch, i.e., BMv2. aim validate full capabilities code feasibility scalability, load resource impact added intra-switch latency. experimental results show approach scales with number forwarded flows achieves per-segment enforcement congested non-congested scenarios very switch extra-latency, finer tuning simply applicable through entry configuration. Applicability analysis hardware line rate performance provided.