The increasing demand for higher bandwidth to support Big Data has driven the need for ever-increasing Ethernet speeds, starting with 10 Gig in 2004 to the introduction in 2010 of 40 Gig with 4 fibers transmitting and 4 fibers receiving at 10 Gbps (40GBASE-SR4) and 100 Gig with 10 fibers transmitting and 10 fibers receiving at 10 Gbps (100GBASE-SR10).
It felt like a Monday morning when the call, actually an e-mail, came in. “I think my DSX is broken!” As you know, they are really tough machines and, when it looks like the Fluke is wrong, usually it isn’t.
“What makes you think it is broken?” I asked, “How does this failure manifest itself?”
“The tester is failing links that used to pass.”
Verification of test reference cords is easy, right? Yes, usually…but not always. After the power meter is set to 0 dB via the reference procedure, the loss of a mated connector pair is expected to be less than 0,20 dB for single-mode (e.g., -0,20 dB). Let’s examine one scenario where a loss is not negative (e.g., +0,15 dB).
The typical process for validating the loss of a connector, to verify if it is “reference grade” for example, is as follows:
Depending in which functional area of the data center you are testing, there are different applications, cabling and connectivity that you will encounter. Understanding the functional areas of the data center and what you will likely need to test in each can help prepare you for data center testing.
What Are the Spaces?
The latest TIA standard for balanced twisted-pair cable systems – TIA 568.2-D – was approved for publication during the TR-42.7 meeting on 12 июня 2018 г.. It will replace TIA-568-C.2 and is expected to be published in the coming weeks.
For the past year (or more), we’ve been talking about many of the changes we will see in this standard, and now that it’s approved, we decided a recap is in order.
If you are familiar with deployments where a horizontal cable run terminated on one end to an RJ-45 plug connects directly into a device, then you are familiar with what is now referred to as a Modular Plug Terminated Link, or MPTL (even if it wasn’t always referred to in this way).
While many of our blog readers are well versed in designing, installing and testing cabling systems, some of you may be new to the industry and still trying to make sense of the various performance parameters, standards and testing requirements that today’s cabling systems must meet to support the latest applications, acquire a vendor’s system warranty and ensure a successful installation for your customers.
Over the past few years, several manufacturers have released 28 AWG patch cords that offer a smaller diameter to help improve airflow around active equipment and ease cable management at high density patching areas due to reduced congestion and a smaller bend radius.
Despite causing a bit of controversy in the industry since they were not originally recognized within ANSI/TIA cabling standards that require twisted-pair structured cabling to consist of 22 AWG to 26 AWG cables, these skinny patch cords continued to grow in popularity.
When it comes to calculating loss budget, it’s important to know the loss limits for the given application as specified by industry standards. But if I really want to know how to design a system to these limits, you also need to know the loss of the specific vendors’ cables and connectivity you plan to deploy—and that can impact exactly which components you specify. This can make the task a bit tricky as not all cables and connectors are created equal.
Let’s take a look at a real-world example.