In-order INT: Efficient Reordering of Out-of-order In-band Network Telemetry Packets via CPU-FPGA Co-design

With the emergence of Software-Defined Networking (SDN) and data plane programmability, In-band Network Telemetry (INT) has become a novel network measurement approach, enabling end-to-end, hop-by-hop network visibility. However, due to the complexity of network topologies and limitations in telemetry orchestration schemes, telemetry servers often encounter severe out-of-order issues when processing incoming telemetry reports. This results in stale and unreliable data source for upper-layer telemetry applications. This paper proposes a CPU/FPGA co-designed out-of-order reordering system for INT, which combines online and offline sorting techniques to enhance the processing efficiency of telemetry servers. To the best of our knowledge, this is the first study addressing out-of-order reordering in INT. Experimental results show that compared to a CPU-only solution, our approach achieves a 12.5 X speedup on the 10 GE NIC.