  Existing traffic engineering (TE) solutions performs well for software
defined network (SDN) in average cases. However, during peak hours, bursty
traffic spikes are challenging to handle, because it is difficult to react in
time and guarantee high performance even after failures with limited flow
entries.
  Instead of leaving some capacity empty to guarantee no congestion happens due
to traffic rerouting after failures or path updating after demand or topology
changes, we decide to make full use of the network capacity to satisfy the
demands for heavily-loaded peak hours. The TE system also needs to react to
failures quickly and utilize the priority queue to guarantee the transmission
of loss and delay sensitive traffic. We propose TED, a scalable TE system that
can guarantee high throughput in peak hours. TED can quickly compute a group of
maximum number of edge-disjoint paths for each ingress-egress switch pair. We
design two methods to select paths under the flow entry limit. We then input
the selected paths to our TE to minimize the maximum link utilization. In case
of large traffic matrix making the maximum link utilization larger than 1, we
input the utilization and the traffic matrix to the optimization of maximizing
overall throughput under a new constrain. Thus we obtain a realistic traffic
matrix, which has the maximum overall throughput and guarantees no traffic
starvation for each switch pair. Experiments show that TED has much better
performance for heavily-loaded SDN and has 10% higher probability to satisfy
all (> 99.99%) the traffic after a single link failure for G-Scale topology
than Smore under the same flow entry limit.
