Data Center Technologists
Data Center Technologists
25GbE: There’s a New Type of Server Access in the Data Center, and Juniper is Well-Positioned to Support It

There is no denying that video-based traffic has increased exponentially over the last few years. People are consuming massive amounts of video, gaming and other rich media on mobile phones and tablets over IP networks, and this trend shows no signs of slowing anytime soon. In fact, a recent report by the IEEE 802.3 Ethernet working group suggests the CAGR for IP network growth will be nearly 32%.



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Figure 1: IP network traffic growth


At the same time, the 10GbE servers that produce the video traffic are operating at near full capacity.  Since demand is not abating, there are essentially two options to keep pace:  either get more out of the same servers (the CPU technology would allow the I/O to be pushed to 40Gbps), or increase the number of servers.  Both choices have economic implications for providers; while 40GbE is a perfect fit for 10GbE access networks, migrating to 40GbE speeds for server access has several consequences, including:

  • Changing the cabling infrastructure: Four times more cabling is required to upgrade the 10GbE access network, as the 40GbE standard is simply a multiplexing of 10GbE signals over four lanes.
  • Customers are not necessarily looking for a 4x increase in server connectivity. Instead, they are looking for something incremental—a higher–performance solution that is closer in cost to 10GbE. Further, 40GbE server access requires very high core bandwidth if wire-speed fabrics are built.


There is a solution that allows customers to keep pace with growing demand for server access bandwidth, one that is cost efficient and improves network performance significantly.  That solution is 25GbE. The 25GbE/50GbE consortium, of which Juniper is a member, was founded two years ago to drive the standard development effort (for a complete list of members, visit


Some of the key advantages of 25GbE technology are following

  • It runs on a pair of cables just like 10GbE, so moving to 25GbE does not require any cabling infrastructure upgrades—it is fully compatible with the existing 10GbE infrastructure.
  • It is cost efficient—the economics of 25GbE are similar to 10GbE, so customers get the benefit of 2.5 times the speed and performance with the same 10GbE economics.
  • Four times 25GbE is equal to 100GbE, resulting in networks that can provide uniform oversubscription and require fewer 100GbE uplinks to build wire-speed fabrics for server access. Likewise, 50GbE performance can be achieved by simply combining a pair of 25GbE interfaces.
  • Building networks with 25GbE interfaces require fewer SERDES (one for 25GbE vs. four for 40GbE), resulting in better overall power consumption.


Broadcom recently announced the availability of 25GbE controllers for servers. As shipments for these controllers begin to grow, the need for network access switches that can support 25GbE speeds will grow as well.  Juniper is fully committed to supporting 25GbE technology, as it provides a clear advantage for environments where 10GbE I/O is no longer sufficient but migrating to 40GbE is not a cost–efficient option.  For these users, 25GbE will drive network performance in a cost-efficient manner, and Juniper will be shipping 25GbE access switches with 100GbE uplinks on par with industry timelines this year.

These 25GbE access switches, combined with dense 100GbE spine switches, will allow customers to build a highly scalable network fabric. Juniper QFX10000 switches, for instance, deliver industry-leading 100GbE scale with more than 2.5 times the density of the nearest competitor. The QFX10016 switch supports 480 wire-speed 100GbE ports in a 21RU form factor, which means customers can have two QFX10016s supporting 960 wire-speed 100GbE ports—that’s 96 Tbps of capacity!—in a single rack.

Furthermore, low-cost direct-attach copper (DAC) 25GbE optics will be available this year with an industry-standard MSA (multi-source agreement) that Juniper is driving along with optical vendors.

With the availability of 25GbE networking, combined with the highest-density 100GbE switches, Juniper will help customers build the highest performance networks suitable for the most demanding workloads.

Juniper Employee

Concise, to the point - articulates the 25G value prop very clearly.