A novel approach to accurately compute an IP traffic matrix using optical bypass

The traffic matrix is not readily available in IP networks and it can neither be calculated from link loads and routing information due to the ill-posed nature of the correspondent linear system, nor can it be estimated accurately enough. In this paper, we propose a novel approach to measure individual origin-destination flows using optical bypass to increase the rank of the said linear system, which let us accurately calculate a large portion of the IP traffic matrix. The method is inspired by optical bypass techniques known from multi-layer traffic engineering in IP-optical systems, which we use in this novel context. The traffic matrix calculation is possible due to the manner in which we create bypasses, which makes our method effective and unique. Our results show that already a small number of bypasses is sufficient to obtain almost the entire traffic matrix, while the impact of our method on network design and operation is negligible.