EE380 Computer Systems Colloquium

A Topologically Optimal Internet
Wednesday, September 28, 2016 - 4:30pm
Gates B03
Alan Huang, Ph.d. and Scott Knauer. Ph.d.
Abstract / Description: 

Current packet backbone networks are based on telephone, railroad, or highway networks. They were designed to minimize the total link length. Packet switched networks are different from circuit switched networks in that they should be designed to minimize the number of hops instead of the total link length. Minimizing the number of hops reduces the latency, power consumption, and cost. This also increases network efficiency by completely eliminating the “bypass” packets that needless pass through the routers.

In more detail, the number of hops can be reduced by 2X by converting the network into a toroid. The number of hops can be further reduced by recasting the network into N-dimensional hypercube or into a multistage network, such as a Perfect Shuffle or Banyan. The multistage networks can be made redundant by adding an extra stage. This increases the fault tolerance and reduces the fabric blocking of the network. The reduced fabric blocking increases the network's ability to carry voice and video. Dense Wavelength Division Multiplexing (DWDM) channels on existing optical fiber links can be connected together to implement these topologies. The DWDM channels decouple the network topology from the geographical constraints. These topologies are compatible with all the layers of the OSI stack.


The Stanford EE Computer Systems Colloquium (EE380) meets on Wednesdays 4:30-5:45 throughout the academic year. Talks are given before a live audience in Room B03 in the basement of the Gates Computer Science Building on the Stanford Campus. The live talks (and the videos hosted at Stanford and on YouTube) are open to the public.


Alan Huang is an expert in packet switching and optics. While at Bell Labs, he worked on high performance packet switches for voice and video. He co-invented the Batcher / Banyan switching network and helped design AT&T's first ATM switch. He also managed the development of an optical pipelined processor, a photonic switching network, vertical cavity surface emitting lasers (VCSEL), planar optics, and ultrafast (> 1Tbs) all-optical logic. After Bell Labs he helped start Terabit Corporation. While at Terabit, he worked on scalable, fault tolerant routers, DARPA's Next Generation Internet (NGI) project, and ultrafast optical networks. He has a BS and MS in EE from Cornell and a Ph.D. in EE from Stanford. He has over 20 technical publications and 30 US patents.