Real-time optical transponder prototype with autonegotiation protocol for software defined networks

We present a prototype transponder with fast synchronized change of parameters in the case of traffic quality degradation thanks to link impairment detection and autonegotiation capabilities. This concept has been implemented and validated in real time using a field programmable gate array (FPGA) platform, a Raspberry Pi, and a commercial transponder. We introduce an autonegotiation protocol for local decision-making between two transponders. We measure the latency added by this protocol processing cores inside the FPGA. We then integrate this transponder prototype inside a network testbed, where we compare its performance in detecting and resolving a soft failure against a centralized software-defined network control and management plane. Our solution proves to be 2 times faster and shows less variability on average than a centralized one. This work is complementary to control plane decision-making and brings further flexibility with the idea in mind to promote wider use of reconfigurations toward close-to-zero-margin optical networks.