How to build a 100,000-port Ethernet switch

University of California at San Diego researchers Tuesday are presenting a paper describing software that they say could make data center networks massively scalable.

The researchers say their PortLand software will enable Layer 2 data center network fabrics scalable to 100,000 ports and beyond, and they even have a prototype running at the school’s Department of Computer Science and Engineering’s Jacobs School of Engineering.

Their breakthrough is outlined in paper titled “PortLand: A scalable Fault-Tolerant Layer 2 Data Center Network Fabric” that is being presented at the SIGCOMM 2009 event in Barcelona this week.

Slideshow: Evolution of Ethernet

"With PortLand, we came up with a set of algorithms and protocols that combine the best of layer 2 and layer 3 network fabrics," said Amin Vahdat, senior author of the paper and a computer science professor at UC San Diego, in a statement. "Today, the largest data centers contain over 100,000 servers. Ideally, we would like to have the flexibility to run any application on any server while minimizing the amount of required network configuration and state."

The data center has been a hotbed of activity among leading vendors such as Cisco, HP, Juniper and IBM, some of which are retrofitting existing offerings and others of which are building products from scratch.

PortLand will work with existing hardware and routing protocols, according to the researchers, which include graduate students who worked with Vahdat.

"Our goal is to allow data center operators to manage their network as a single fabric," according to Vahdat, who maintains a blog called Idle Process. "We are working toward a network that administrators can think of as one massive 100,000-port switch seamlessly serving over one million virtual endpoints."

Key to this is the development of system for servers to find one another without broadcasting their requests across an entire network. Under PortLand, switches use what are called Pseudo MAC addresses and a directory service to locate servers they need to connect, including new virtual servers. The researchers say this setup can eliminate much of the manual labor required to build a Layer 3 network.

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