Computing Now Exclusive Content — February 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

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

by George Lawton

Widespread virtualization has made data center operations more efficient, but it has also raised serious management issues. Each of the major virtualization platforms currently supports a unique virtual LAN protocol. Organizations with large data centers must therefore manage multiple virtual networking protocols.

In response, companies that normally compete for control of the data center market are working to develop standards for virtual Ethernet port aggregation (VEPA) to ease the management issues. The IEEE 802.1Qbg and 802.1Qbh VEPA standards will move networking from virtual servers to dedicated Ethernet switches. This will help centralize networking in dedicated equipments for better performance, security and management. It will also help reduce the computing overhead on virtual servers as they scale to support more virtual machines.

Traditional virtual switches generate several challenges, said Shehzad Merchant, senior director of strategy for Extreme Networks. The first is scaling. As data centers and IT managers add more virtual machines to physical servers, less horsepower is available for network processing tasks. Also, it's more difficult to troubleshoot problems using traditional network management tools because the traffic is switched on the server rather than through a dedicated switch.

Another issue is that the Xen Server, Hyper-V, and ESX virtual machine monitors, also known as hypervisors, each support a different virtual switch protocol so the network administrator has to deal with a heterogeneous network.

The new proposals have broad industry support. VEPA technology will be implemented by network equipment vendors, Ethernet card vendors, and hypervisor vendors. Companies working on the VEPA standardization include 3Com, Blade Network Technologies, Brocade, Cisco, Dell, Extreme Networks, HP, IBM, Intel, Juniper Networks and Qlogic.

The Qbg and Qbh proposals reflect two different approaches for implementing VEPA. The proposal championed by HP is being rolled into 802.1Qbg, which will be optimized for edge switches. Another approach, championed by Cisco, is being rolled into 802.1Qbh and optimized for centralized switches.

The lack of standardization isn't hampering the adoption of virtualization now, but Jon Oltsik, senior principal analyst at Enterprise Strategy Group, said that achieving virtualization's full benefits will require better integration between the physical and virtual worlds. "The way people are networking now using virtual switches in the hypervisor will not scale," he said. "It's holding back the industry."

Under the Hood

Virtualization technology enables multiple virtual servers to run on a hypervisor installed on one physical server. This helps improve computer utilization and application reliability, so the use of virtualization is exploding, particularly in data centers. Gartner predicts that 50 percent of all workloads will run inside virtual machines by 2012.

The hypervisor emulates all the hardware and network connections of a physical computer to each virtual machine. VEPA will let administrators move the virtual networking functionality from the hypervisor to a dedicated physical switch.

This hasn't been possible in the past owing to traditional Ethernet limitations that precluded "hairpin turns," in which data packets travel back through the same physical port they came from. Consequently, network traffic between virtual machines on the same physical server had to travel on a specialized virtual networking protocol running on the server. The new VEPA protocols allow these hairpin turns, so organizations can move network traffic between virtual machines off the server and on to dedicated network switches.

VEPA Challenges

One downside of VEPA is increased network traffic, since each data packet has to make a round-trip down the Ethernet cable rather than just going across the physical server's internal bus. Oltsik said that CPU performance is typically a more significant limiting factor on servers than network bandwidth. Today's networks generally support 10 Gbps and are expected to support 40 to 100 Gbps within the next two years. The processing overhead is a much bigger limitation.

One challenge to VEPA adoption is the legacy hardware that doesn't support hairpin-turn networking, said Merchant. Organizations will have to physically replace these switches and networking cards to adopt VEPA. However, vendors such as Extreme Networks are now shipping equipment that will be upgradable to VEPA with a software update.

Another challenge is infighting among the vendors between the two proposed standards. "The sooner they can agree on them, the sooner they can start putting VEPA into products," Oltsik said. "Having both Qbh and Qbg is an issue. But regardless of whether one gets adopted or both do, standardization is the right thing to do."

For more information about 802.1Qbg, see; for more information about 802.1Qbh, see

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