Computing Now Exclusive Content — January 2011

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

To Be or NAT to Be?

by George Lawton

The imminent exhaustion of IPv4 addresses is driving the transition to IPv6. But carriers face the challenge of supporting the new addressing scheme, while maintaining backward compatibility with existing IPv4 traffic. Originally, the IETF advocated a transition approach, called dual stack, of having both IP stacks running simultaneously — mainly because IPv6 is not backwards compatible with IPv4. Given this, some legacy applications might always require some way to the bridge the two protocols.

This is where network address translation (NAT) came in. The quick fix was a NAT and protocol translation (NAT-PT) approach. But multiple performance and security issues plague NAT-PT, and the approach can break applications.

Recently, Comcast developed another approach called Dual-Stack Lite (DS-Lite), which promises to solve these problems. Core-router vendors Cisco and Juniper, along with tunnel-broker vendor GoGoNET6 announced support for DS-Lite, and carriers are waiting on the sidelines to see if it works as well as expected. Others believe that a better implementation of NAT, called NAT64 could provide a smoother transition.

Planning the Path to IPv6

IPv6 proponents started planning the transition to IPv6 in 1993, but infighting among various camps and the adoption of NAT technology forestalled the process. Although NAT helped slow the need for the transition, the growth of the Internet has finally exhausted the supply of new IPv4 addresses.

"I believe that IPv6 is here now," said Bob Fink, who helped develop the new protocol while a computer scientist at Lawrence Berkeley National Laboratory. "I'm hearing from more than enough people of a newer generation that doesn’t care about all of the old reasons they didn't want to go to IPv6 20 years ago. They know that if they want a single network that grows, you have to implement IPv6."

The IETF has been working on a technical solution to the IPv4/IPv6 transition for over a decade. In 2000, it issued RFC 2766 which proposed NAT-PT as one transition approach. But researchers uncovered numerous problems with it, such as breaking the end-to-end use of IPSec, said Jeremy Duncan, IPv6 architect for Command Information.

NAT-PT also uses up random TCP and UDP ports, which could cause applications that rely on the ports to malfunction. It also causes packet fragmentation and breaks the function of DNS record translation, which reduces network efficiency and functionality. After the first round of experimentation, the IETF deprecated NAT-PT to historical status, elaborating its technical problems in RFC 4966 in 2007.

Building a Better NAT

Interest resurged in finding other ways to support ITv4-IPv6 translation and make it friendlier on the network, said Duncan. Most of the approaches involve two NAT levels: one on the customer premise and another between the customer premises and the carrier. These schemes are usually described in terms of where the transition takes place. For example, NAT 444 uses multiple banks of IPv4 addresses. This extends the use of IPv4 protocols but doesn’t solve the security, latency, and performance issues, said Duncan. It therefore hasn't seen much traction.

Carrier Grade NAT (CGN) is a more robust approach that solves many of these problems and provides multiple configurations such as NAT 64, DNS 64, and NAT 464, which connect IPv4 equipment on the premise with either the IPv6 network or the IPv4 network. But CGN's extra layers of translation — around three — can introduce extra computation and latency when IPv6 equipment on the customer’s premise needs to be translated to IPv4 and back.

"A lot of carriers looked at this issue and thought it was an incredibly complex solution," said Duncan.

Tunnel or Translate?

To solve these problems, Comcast's DS-Lite encapsulates the IPv4 packets into IPv6 and leaves native IPv6 packets untouched. Given that IPv6 is never translated, DS-Lite requires less overhead than approaches that translate between the two protocols. With tunneling IPv4, Duncan explained, the router just has to encapsulate the IPv4 header, which is simpler than having to map the local private IPv4 address to a port number.

CGN support predates DS-Lite in core routers, but most carriers are holding off on implementing either technology until the Comcast trials have demonstrated real-world robustness, said Duncan. If it works as expected, he sees DS-Lite becoming the dominant approach in the service provider transition to IPv6.

Other industry experts believe that NAT 64 provides a cleaner migration path for most network providers because it uses only one box on the network for translation instead of the two required for tunneling.

Doug Junkins, CTO of NTT America explained, "DS-Lite works well for cases when the network operator controls the router in the home and can make sure it's implemented properly there. But NAT 64 doesn't have the requirement for both ends of the connection to be similar."

George Lawton is a freelance journalist in Guerneville, CA. Contact him via his website