Abstract
We study the problem of Traffic Engineering in multi-site Software Defined Network (SDN). In our system, we virtualize the physical links with virtual tunnels and each tunnel will be represented by a label. We propose to decouple the flow table into two tables: the more static tunnel table, and the more dynamic path table, for higher flexibility. The tunnel table contains a set of pre-built tunnels, while the path table matches each traffic flow to the labels. We formulate two optimization problems for tunnel construction and path assigner. Four algorithms are proposed to solve the Traffic Engineering properly, and a real testbed is implemented to prove the concept. Furthermore, we also compare the proposed solution with Segment Routing~(SR) and Ryu Simple Routing~(RSR), the experimental results show that our solution outperforms SR and RSR: 1) maximal link utilization reduction between 20\% and 46\% compared to SR, 30\% and 50\% compared to RSR. 2) Initial delay reduction by 39\% compared to SR, and 93.2\% compared to RSR. In addition, our proposed solution also brings load balancing and error resilience features to the network system.