Computing Now Exclusive Content — May 2010

News Archive

July 2012

Gig.U Project Aims for an Ultrafast US Internet

June 2012

Bringing Location and Navigation Technology Indoors

May 2012

Plans Under Way for Roaming between Cellular and Wi-Fi Networks

Encryption System Flaw Threatens Internet Security

April 2012

For Business Intelligence, the Trend Is Location, Location, Location

Corpus Linguistics Keep Up-to-Date with Language

March 2012

Are Tomorrow's Firewalls Finally Here Today?

February 2012

Spatial Humanities Brings History to Life

December 2011

Could Hackers Take Your Car for a Ride?

November 2011

What to Do about Supercookies?

October 2011

Lights, Camera, Virtual Moviemaking

September 2011

Revolutionizing Wall Street with News Analytics

August 2011

Growing Network-Encryption Use Puts Systems at Risk

New Project Could Promote Semantic Web

July 2011

FBI Employs New Botnet Eradication Tactics

Google and Twitter "Like" Social Indexing

June 2011

Computing Commodities Market in the Cloud

May 2011

Intel Chips Step up to 3D

Apple Programming Error Raises Privacy Concerns

Thunderbolt Promises Lightning Speed

April 2011

Industrial Control Systems Face More Security Challenges

Microsoft Effort Takes Down Massive Botnet

March 2011

IP Addresses Getting Security Upgrade

February 2011

Studios Agree on DRM Infrastructure

January 2011

New Web Protocol Promises to Reduce Browser Latency

To Be or NAT to Be?

December 2010

Intel Gets inside the Helmet

Tuning Body-to-Body Networks with RF Modeling

November 2010

New Wi-Fi Spec Simplifies Connectivity

Expanded Top-Level Domains Could Spur Internet Real Estate Boom

October 2010

New Weapon in War on Botnets

September 2010

Content-Centered Internet Architecture Gets a Boost

Gesturing Going Mainstream

August 2010

Is Context-Aware Computing Ready for the Limelight?

Flexible Routing in the Cloud

Signal Congestion Rejuvenates Interest in Cell Paging-Channel Protocol

July 2010

New Protocol Improves Interaction among Networked Devices and Applications

Security for Domain Name System Takes a Big Step Forward

The ROADM to Smarter Optical Networking

Distributed Cache Goes Mainstream

June 2010

New Application Protects Mobile-Phone Passwords

WiGig Alliance Reveals Ultrafast Wireless Specification

Cognitive Radio Adds Intelligence to Wireless Technology

May 2010

New Product Uses Light Connections in Blade Server

April 2010

Browser Fingerprints Threaten Privacy

New Animation Technique Uses Motion Frequencies to Shake Trees

March 2010

Researchers Take Promising Approach to Chemical Computing

Screen-Capture Programming: What You See is What You Script

Research Project Sends Data Wirelessly at High Speeds via Light

February 2010

Faster Testing for Complex Software Systems

IEEE 802.1Qbg/h to Simplify Data Center Virtual LAN Management

Distributed Data-Analysis Approach Gains Popularity

Twitter Tweak Helps Haiti Relief Effort

January 2010

2010 Rings in Some Y2K-like Problems

Infrastructure Sensors Improve Home Monitoring

Internet Search Takes a Semantic Turn

December 2009

Phase-Change Memory Technology Moves toward Mass Production

IBM Crowdsources Translation Software

Digital Ants Promise New Security Paradigm

November 2009

Program Uses Mobile Technology to Help with Crises

More Cores Keep Power Down

White-Space Networking Goes Live

Mobile Web 2.0 Experiences Growing Pains

October 2009

More Spectrum Sought for Body Sensor Networks

Optics for Universal I/O and Speed

High-Performance Computing Adds Virtualization to the Mix

ICANN Accountability Goes Multinational

RFID Tags Chat Their Way to Energy Efficiency

September 2009

Delay-Tolerant Networks in Your Pocket

Flash Cookies Stir Privacy Concerns

Addressing the Challenge of Cloud-Computing Interoperability

Ephemeralizing the Web

August 2009

Bluetooth Speeds Up

Grids Get Closer

DCN Gets Ready for Production

The Sims Meet Science

Sexy Space Threat Comes to Mobile Phones

July 2009

WiGig Alliance Makes Push for HD Specification

New Dilemnas, Same Principles:
Changing Landscape Requires IT Ethics to Go Mainstream

Synthetic DNS Stirs Controversy:
Why Breaking Is a Good Thing

New Approach Fights Microchip Piracy

Technique Makes Strong Encryption Easier to Use

New Adobe Flash Streams Internet Directly to TVs

June 2009

Aging Satellites Spark GPS Concerns

The Changing World of Outsourcing

North American CS Enrollment Rises for First Time in Seven Years

Materials Breakthrough Could Eliminate Bootups

April 2009

Trusted Computing Shapes Self-Encrypting Drives

March 2009

Google, Publishers to Try New Advertising Methods

Siftables Offer New Interaction Model for Serious Games

Hulu Boxed In by Media Conglomerates

February 2009

Chips on Verge of Reaching 32 nm Nodes

Hathaway to Lead Cybersecurity Review

A Match Made in Heaven: Gaming Enters the Cloud

January 2009

Government Support Could Spell Big Year for Open Source

25 Reasons For Better Programming

Web Guide Turns Playstation 3 Consoles into Supercomputing Cluster

Flagbearers for Technology: Contemporary Techniques Showcase US Artifact and European Treasures

December 2008

.Tel TLD Debuts As New Way to Network

Science Exchange

November 2008

The Future is Reconfigurable

New Product Uses Light Connections in Blade Server

by George Lawton

A company has delivered the first version of a product that uses light signals, instead of cables and switches, to connect blade-server nodes. Lightfleet has sold and installed its Beacon prototype, a 32-node server, to Microsoft Research. Beacon uses the company's Direct Broadcast Optical Interconnect (DBOI).

"The key innovation is the broadcast simultaneity," said Lightfleet CEO John Peers. "This is not a switch in the traditional sense. It's a permanent continuous interconnect. There's no switch so there’s no congestion. Instead of having to create and maintain a pathway for a connection, all of the connections are maintained all of the time."

Because DBOI uses broadcast light signals to communicate, it reduces power consumption, latency, and data skew compared with other interconnect technologies. More important, it simplifies memory sharing among multiple nodes in a cluster, blurring the line between symmetric multiprocessing (SMP) and a traditional cluster supercomputer.

According to Lightfleet senior fellow Bill Dress, "We get the benefits of the computing power of an SMP but without the limits of the bus and the OS single point of failure."

Interconnect technologies are fundamental to system performance. Even if a server has fast chips and a large amount of memory, slow interconnects will reduce overall performance for many types of modeling and simulation applications. "DBOI enables an architectural shift, rather than just providing a faster interconnect," noted Bob Laliberte, senior analyst for Enterprise Strategy Group an industry analysis firm.

How DBOI Fits In

One big challenge in high-performance computing (HPC) systems lies in optimizing the communications between multiple processors. High-end SMP systems use specially designed (and expensive) buses and crossbar switches that let multiple processing cores share an operating system and memory.

Alternatively, multiple commodity-grade compute blades can be clustered using interconnect technologies such as Ethernet, Infiniband, or Fibre Channel. Each blade has a wire or fiber connecting to a centralized switch, which passes the messages along to other blades. However, this approach can send messages only from one point to another. If a particular message needs to go to multiple blades, the switch has to make copies and forward each one to the appropriate destination. Another solution is to use a special address and an unreliable broadcast mode to all nodes and let the application software determine whether the message is for the receiving host.

In contrast, DBOI broadcasts all of the traffic from one blade to all the other blades simultaneously. Each blade is connected via a PCIe backplane to the DBOI system, and a laser beam modulates the DBOI broadcast data from the host. The beam bounces off the system’s rear surface, and all 32 nodes can read it simultaneously. At this point, the individual nodes' receiving hardware determines whether the node is participating in this message. If so, it passes the message to the host; if not, it discards the message.

In the prototype Microsoft implementation, each of four DBOI modules contains eight transmitters and 32 receivers handling communications for a set of eight compute nodes. The 32 separate receivers in each set allow a node to spatially differentiate between the signals from the different nodes' transmitters.

Electronics underneath the transceiver identify and forward packets destined for a particular node. Each node transmits slightly faster than a single PCIe lane but uses all available PCIe lanes to move data between the DBOI module and host. In the prototype, each host uses a four-lane PCIe 1.1 interface for a gross data rate to and from the host of 10 gigabits per second (Gbps). Future versions will move to eight lanes of PCIe 2.0 or 3.0, increasing the host bandwidth. In the logical configuration, each host monitors all 32 channels simultaneously but the protocol electronics forwards only the messages that an individual host needs to receive.

The transmitter uses direct-modulation techniques on a laser. A set of lenses causes each beam to arrive at a different location on the optical side of the DBOI module. The optics creates a space-division multiplexer that lets receivers differentiate the individual signals. Because the signals don't interfere with each other, the communication path remains open.

DBOI differs from optical networking technologies such as Intel's Light Peak, because the broadcast optics operates in a defined space rather than a point-to-point fiber-optic connection.

Specific DBOI Improvements

DBOI could change the programming model for HPC applications. Its broadcast capability supports a publish/subscribe model, giving every node equal access to the data. Its similarities to a shared-memory SMP system simplify programming across HPC clusters in comparison with Message Passing Interface. Programmers don't have to account for the data-arrival skew, so they can concentrate on the application’s logical operation.

"You can't do broadcasting with any other interconnect," said Brian Garrett, vice president of ESG Labs. "It wasn't easy for every node to have a shared-memory view of a big problem before. In general, you passed messages around."

DBOI also reduces the data-arrival skew across system nodes. This improves performance when synchronizing multiple processes — for example, in a relational database. In a traditional interconnect, the path each message travels can change, which can affect the precision of data-block synchronization. With DBOI, the message-travel distance never changes, and the data skew is a few nanoseconds compared with microseconds in an Infiniband system.

Lightfleet's Peers estimates that the prototype design consumes one-third the power of comparable blade systems. By eliminating an external switch, BDOI eliminates all the power required to move signals down copper wires. In addition, it reduces the communications overhead of sending the same data to multiple nodes.

Initial DBOI implementations will focus on HPC applications that involve considerable communication across nodes, such as financial simulations on Wall Street. As the prices come down, the technology could be ported to high-end servers as a way to increase speed and lower costs. Eventually, Peers expects the technology to find its way into routers and other communications-intensive equipment.

George Lawton is a freelance technology writer based in Guerneville, California. Contact him at