The rapid growth in data center traffic is driving the need for increased performance and overall bandwidth of networking equipment, including optical interfaces and Ethernet switches, which are based on pluggable transceivers today. But looking just a few years ahead, bandwidth scalability challenges are looming in terms of density, cost, and power; challenges that require tighter integration of optics and networking silicon. This paper reviews the motivation for integration, the enabling technology elements, and discusses how advanced packaging and Silicon Photonics enable higher density, reduced power per bit, and ultimately the continued scalability of network bandwidth and performance.