Relevance of Fragmentation in Different Elastic Optical Networks

In the quest to improve capacity in optical networks, dynamic Elastic Optical Networks (EONs) increase spectrum utilization and therefore, improves the number of accepted connections. However, EONs are claimed to be prompt to spectrum fragmentation due to highly granular requests and dynamicity, a phenomenon that could potentially reduce the effectiveness of EONs. However, this work shows the limited impact of fragmentation by evaluating two types of networks: i) Core networks, differing in terms of size and connectivity; and ii) Data Center networks, varying in size and architecture. The results show that fragmentation is an important event only in data centers, specially with fine granularity demands. In core networks, operators should focus to reduce the congestion in the main central links rather than fragmentation.