Jennifer Gossels will present her FPO, "Joint Optimization for Robust Network Design and Operation" on Wednesday, 2/19/2020 at 9:30am in CS 402.

The members of her committee are as follows: Jennifer Rexford (adviser), Readers: Kai Li and Gagan Choudhury (AT &T Labs); Examiners: Michael Freedman, Wyatt Lloyd, and Jennifer Rexford

A copy of her thesis, is available upon request. Please email ngotsis@cs.princeton if you would like a copy of the thesis.

Everyone is invited to attend her talk. The talk abstract follows below:

The Internet is an essential part of modern life, and Internet Service Provider (ISP) backbone

networks are integral to our Internet experience. Therefore, ISPs must build networks that

limit congestion, even when some equipment fails. This network design problem is complicated,

because an optimal network design must consider the eventual runtime configuration.

An ISP makes network design decisions, such as purchasing and placing equipment, on long

timescales (months or years) and network operation decisions, such as routing packets, on

short timescales (seconds). Design and operation interact such that the ISP must solve the

network operation problem as a sub-problem of network design, rendering the network design

problem difficult to formulate and computationally complex.

Today ISPs resort to a variety of simplifications; they fail to take advantage of the

reconfigurability offered by modern optical equipment or the opportunity to mix more- and

less-powerful switches throughout their networks. In this dissertation, we show how ISPs can

incorporate each of these factors into their network design and operation models to produce

less expensive networks without compromising robustness.

In Chapter 2, we explain how reconfigurable optical switches fundamentally change the

network design and operation problems by shifting the boundary between what is fixed at

design time and what is reconfigured at runtime. Then, we present an optimal formulation

for this new problem and heuristics to help our solution scale. In Chapter 3, we describe a

failure recovery protocol that allows ISPs to realize many of the benefits of outfitting their

networks with a homogeneous collection of powerful, “smart” switches, while instead using

a combination of these expensive boxes and less expensive, “dumb” switches.

We make three contributions in each chapter. First, we formulate the network design

optimization by extending the multicommodity flow framework to leverage colorless and

directionless Reconfigurable Optical Add/Drop Multiplexers (Chapter 2) or heterogeneous

nodes (Chapter 3). Second, we devise heuristics to scale our designs to larger topologies.

Finally, we evaluate our ideas on a realistic backbone topology and traffic demands.