Deferred Protection of Deadline-Driven Requests in Inter-Datacenter Elastic Optical Networks

Inter-Datacenter Elastic Optical Networks (IDC-EONs) can serve increasing traffic demands among distributed datacenters (DC). Inter-DC traffic demands are typically characterized by flexibility in terms of start time, end time, and assigned transmission rates. In addition, such traffic demand can have a backup data transfer path that can be flexibly scheduled (as long as it is completed before a certain deadline). Such demands are called Deadline-Driven Requests (DDRs). For high DDR transmission rates, even a few milliseconds of traffic interruption (e.g., due to some equipment failure) can result in huge amount of data loss. Existing protection mechanisms against failures, such as Dedicated Path Protection (DPP), originally designed for transport networks, have limitations in case of IDC-EONs due to high spectrum utilization. This work proposes a novel DPP approach applicable to DDRs in IDC-EONs, called Deferred Protection (DP), which schedules the backup path at a later time than the working path, and its reservation can be gradually removed while the working data is successfully delivered. Illustrative numerical results demonstrate that DP decreases blocking probability and provides more efficient use of spectral resources compared to traditional DPP for realistic case studies.