What is QSFP+ and Why Should You Care?

2015-03-04 18:49:04

If you are thinking about upgrading your server network connections, you may want to know about an emerging plug standard called QSFP+, which stands for Quad Small Form-factor Pluggable. You will find that your blazing fast bandwidth is going to literally depend on these cables in the future.

We have been fortunate that for the past thirty or so years, network upgrades have been relatively straightforward and easy to implement. Back in the early 1990s, Ethernet wasn't very easy to implement, requiring very thick cables the diameter of your finger that couldn't easily be laid around offices.

This "thicknet" or 10Base5 cabling, as it was called, could only run 500 meters and wasn't the easiest of things to work with. Fortunately, 10BaseT Ethernet was invented that could use RJ45 connectors and a central wiring closet, and we have continued to expand the speeds of Ethernet ever since, to 1 Gigabit connections that are common on most laptops and servers today.

But the speed at which data packets can be transmitted over copper cabling is just about tapped out, and as we move into 40 GB connections, we will need to add fiber to our data center diets. The problem is that to get to 40 GB, we will need a lot of fiber strands to connect a machine to the network, 12 strands in fact.

So why bother? Because as more equipment comes with built-in 10 GB Ethernet connections, networks will need to run at faster speeds to aggregate all this traffic. We are upgrading our servers faster than we can upgrade the core networks that connect them, which is never a good position to be in. Use cases such as large collections of virtual machines, or low-latency higher-speed financial trading applications, or massive storage networks for Big Data apps are all examples that will place more loads on existing slower networks.

In the past, fiber connections came in pairs, and were relatively easy to terminate and attach connectors by hand on site by semi-skilled electrical contractors. That isn't going to happen with the QSFP+ connectors. Why? Because of the very thin strands of optical fiber, these have to be terminated by specialized and very expensive machinery that isn't very portable. This lack of "field termination" as the data center folks call it means that IT and cabling managers are going to have to measure carefully the distances that they need their optical cables to run and have custom lengths made with the connectors attached. This means you can't just buy a bulk spool of fiber and cut it to the lengths you need. You have to plan things out.

So when you are thinking of moving to ultra-fast networks, start looking at the cabling runs in your data centers and wiring closets and prepare your replacement strategy well ahead of time. Those cables are going to be a major pain to replace.