Top 5 testing challenges for 40 Gb/s and 100 Gb/s Ethernet

By Jeff Lapak and David Estes, UNH-IOL -- Like any new standard, 802.3ba presents some unique testing challenges for both product developers and users.

By Jeff Lapak, Senior Engineer, and David Estes, Ethernet Research and Development Engineer, University of New Hampshire InterOperability Laboratory (UNH-IOL)

Whether from the data center to the consumer or from high-performance computing environments to service providers, the need for increased bandwidth for transporting data continues to grow. The latest Visual Networking Index forecast by Cisco predicts that Internet traffic will grow fourfold over the next four years, with video content being the number one component driving the growth. As almost all Internet traffic crosses an Ethernet port at some point in its travel, the standards bodies continue to develop new Ethernet-based technologies to efficiently meet the forecasted demand.

The IEEE’s 40 Gb/s and 100 Gb/s Ethernet standard, 802.3ba, is the fastest Ethernet standard to date. This standard addresses the need for increased bandwidth and attempts to overcome some of the inefficiencies, such as link aggregation, associated with other solutions. The 40 Gb/s and 100 Gb/s standard is compatible with previous Ethernet standards, allowing targeted implementation within existing networks. Detailed testing will ensure the interoperability of new products and help those products successfully transition from development to deployment.

RELATED STORY: Ethernet Alliance releases white papers on 40/100G interoperability testing

Like any new standard, 802.3ba presents some unique testing challenges for both product developers and users. As an independent provider of broad-based flexible testing services for the networking industry, and with more than 16 years of experience in Ethernet testing, the UNH-IOL has considerable insight into the challenges companies may face. Here are the top five:

5. Efficiency: Lack of support for full line rates -- Although some available switches and routers may be able to support full line rates, many end stations cannot provide the necessary level of support. When Bit Error Ratio Testing requires sending billions of frames, the time required to send them at less-than-line rates can be lengthy.

4. Ethernet PHY: New adaptors and specialized wavelength splitting tools necessary -- Some of the newly defined PHY types rely on Wavelength-Division Multiplexing (WDM). Multiple signals are carried over one channel with WDM, requiring multiplexers and demultiplexers to combine and split the signals. Previous Ethernet PHY types generally carried only one signal per channel.

3. Expense: High price of frame generation and Bit Error Ratio Testing (BERT) equipment -- Pricing of available test equipment may be out of reach for some labs or organizations. If companies choose to rely on their existing equipment instead, coverage and testable bandwidth could be limited.

2. Equipment: Available test equipment does not provide 100 percent coverage for all parts of the 802.3ba standard -- While oscilloscopes and BERTs may support a majority of electrical testing parameters, detailed testing of Auto-Negotiation, PHY control, Physical Coding Sublayer, and equalization training requires custom test tools – with more capability than an off-the-shelf model can provide.

1. Expertise: Technical expertise of Quality Assurance (QA) engineers -- Many test procedures require advanced knowledge of signal integrity design best practices. Additionally, many measurements require detailed calibration routines and test fixture de-embedding, which some engineers may not be familiar with if they are making a transition to nx10G serial technology from lower signaling rates.

For companies preparing products for the IEEE 802.3ba standard for high speed Ethernet, the UNH-IOL offers a solution to these testing challenges through the 40 and 100 Gigabit Ethernet Consortium, launched in July 2010. The consortium is currently accepting founding member companies who will have an early opportunity to provide input into the testing process and have market ready products as the high speed Ethernet standards evolve. The UNH-IOL collaborative testing model distributes the cost of performing trusted, independent testing and validation through an annual membership.

The fee for participation in the 40 and 100 Gigabit Ethernet Consortium is $24K. More information on becoming a member of the 40 and 100 Gigabit Ethernet Consortium at the UNH-IOL can be found at http://www.iol.unh.edu/services/testing/ethernet.

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