It’s always exciting to deploy in a brand-new cabinet. Often colocation or multi-tenant data centres offer direct cross-connects between cabinets. These cross-connects are typically dropped into cabinets, waiting to be patched.
Engineers and technicians responsible for the deployment of equipment in cabinets need to complete the patching – some keep it tidy while others do not. This usually leads to cable spaghetti, where it becomes impossible to reach equipment through the fibriatelle of cross-connects.
Newer technologies have allowed us to explore different ways to patch systematically, for example, using high-density fibre cassettes. Current cassettes allow for up to 144 fibre cross-connects to be installed per 2U in cabinets.
Let’s review the differences.
High-density fibre cassette versus direct cross-connects
It all depends on the availability of ingredients. NAPAfrica initially accepted direct cross-connects into cabinets. As the number of connections increased, we quickly realised that direct interconnection did not allow for any manageable standard or format.
This made troubleshooting a nightmare since it became near impossible to find the correct cross-connects to work on. It also increased the risk of disrupting services on other cross-connects. Unfortunately, fibriatelle also affects airflow in the rack, leading to increased equipment temperatures.
We changed our cabinet design, including patch panels, single-mode fibre patch leads, and cable management. This allowed us to channel the cables over and around the switches.
With the continued growth of NAPAfrica, we installed approximately 375 new cross-connects per month. In our first cabinet design change, we could theoretically accommodate 816 cross-connects. Still, based on NAPAfrica’s specific design requirements, the new 144-core high-density cassettes allowed 1 008 cross-connects in a single cabinet.
Size matters. When installing patch leads, ensure the cable length is appropriate as excess slack leads to wasted space and the tangling of cables. We have found that one-metre and 1.5-metre cables are perfect for our requirements.
Cabling can pose another issue concerning spacing and accessibility. We use a mixture of standard, single-mode fibre patch leads and MPO cables.
The installed switches allow more connections on a single port using break-out cables. These break-out cables have a single MPO connector on one end with either four or eight-duplex LC single-mode connectors on the other end. This design provides greater density per port but introduces additional complexity due to the bulky cable joints, which use significantly more space than single patch leads. Careful planning is required, not only to keep things tidy, but also to ensure all cabling is within an acceptable bend radius.
On average, a single cabinet in Teraco’s data centres will have 24 cross-connects installed. While this is significantly easier to manage, it remains easy to create cable spaghetti.
Our suggestion is to have a pre-planned patching method that should be followed within cabinets. This includes how cables are channelled, the sequence in which hardware is installed, and whether the deployment will be top-to-bottom or bottom-to-top.
In the end, fibriatelle should become a thing of the past(a).
