Qwest moved internet calls off the voice network by optimizing boxes

Dial-up internet traffic congested the public switched-telephone network because long data calls occupied voice-switching resources. Qwest could add offload equipment, but the value depended on where and how much capacity to install.

The team built an integer programming model and interactive planning tool for metropolitan data-offload networks. It optimized equipment locations and capacities, letting planners compare designs instead of relying on manual placement.

The Interfaces article reports estimated savings of $1.5 million over manual designs and a 25% reduction in expected call blocking. The key was matching relief capacity to the actual topology and traffic, not spreading upgrades evenly.

Offload internet calls at the cheapest nodes

The model attacked congestion at transfer points between voice and data networks.

Capacity and location were optimized together, avoiding stranded equipment.

The interactive tool made the model usable for network design and expansion.

When one network is congested by traffic it was not built for, the best fix may be selective escape valves rather than blanket capacity expansion.

The paper won the Daniel H. Wagner Prize for Excellence in Operations Research Practice and documented how telephone carriers adapted legacy voice networks to the internet surge.