Thananya Baldwin, Sr. Director of Strategic Programs at Ixia
Sr. Director of Strategic Programs at ixia

Why 25GE Now?

May 27, 2015 by Thananya Baldwin

We are already used to seeing Ethernet speeds such as 40GE, 100GE, and even 400GE. When you hear a lot of buzz surrounding 25GE in the industry, you are probably thinking why the slower Ethernet speed is making so much noise? I hope to explain why 25GE is important to the market.

It’s a fact that the world’s data requirements are growing at an exponentially rate.

  • In 2003, it took an entire year (365 days) to create 5 exabytes (5 billion gigabytes) of data.
  • A decade later, in 2013, we generated 5 exabyte of data in 2 DAYS!
  • Today, over 100 hours of video are uploaded to YouTube every minute!

Today’s market must address this growth rate. How can we keep up with the demand, especially when the existing data center servers are based on 10GE technology, with top of rack switches (TOR) having 4x10GE and 40GE ports?

The market's answer: next-generation data centers using 25GE and QSFP28 interfaces.

Market Movement

Let’s take a closer look at two key technology advancements in our market. The first is serializer/deserializer (SerDes) speed migrating from 10Gbps to 25Gbps. The first generation of 100GE was based on 10 electrical lanes operating at 10Gbps each. In 2009 Ixia shipped our K2 load modules, the world’s First 100GE test system, based on 10Gbps SerDes technology. The IEEE standards committee ratified 100GE and 40GE Ethernet speed (IEEE 802.3ba) in 2012.

Then, the 2nd Generation of 100GE came out, based on four electrical lanes at 25Gbps each. There was a lot of technical work done by the industry to create the electrical lanes at this speed. Today, new 100GE systems run on 4 electrical lanes instead of 10 lanes. This is part of IEEE 802.3bj, ratified in 2014.

You should also know that our industry LOVES single lane solutions, as it is the most economical architecture. When 10GE was first introduced, there were 4 XAUI lanes making up 10GE. Then, serial 10GE electrical lanes came along, and the 10GE market took off like a rocket ship.

If you work with FPGAs, you also know that SerDes speeds have shifted from 10GE to 25GE. We will see FPGAs with many 25GE SerDes shipping this year.

The 2nd component is the physical interface called QSFP28. For 40GE, the interface is called QSFP+. QSFP+ has 4 lanes of 10GE (either electrical or optical). At Ixia, Everest (FlexAP) has 4 QSFP+’s on the front panel.

For 2nd generation 100GE, the interface is called QSFP28 (which is the same physical size as QSFP+). Each QSFP28 still has 4 lanes, but each runs at 25Gbps instead of 10Gbps. This gives the industry a 2.5x improvement in port density with the same power requirements.

The next-generation data centers, being called “cloud scale data centers,” “web scale data centers,” or “hyper scale data centers,” will be moving to 25GE technology very soon, and will have 4x25GE and 100GE ports in an attempt to keep up with increasing network demands (while maintaining control on costs).

In summary, together with 25GE-based 100GE, the 25GE roll-out is happening this year—and Ixia is ready to help validate vendor implementations with our 25GE solution!

Additional Resources:

Ixia’s 25GE test solution