Rack Enclosure Basics and Buying Guide

With an increasing demand for better cable management involved with countless fiber cables, fiber optic enclosure, especially rack enclosure, has become extremely important than ever before! Then, what is rack enclosure? How can we choose it? Let’s find out together in the rest of this post.

What Is Rack Enclosure?

Rack enclosure, or rack mount enclosure, is a high-density equipment which offers higher performance to house, organize, manage and protect fiber optic cables. It is widely used in enterprise data centers, server rooms, airports, schools, etc.

As one of the most important equipment for cable management, rack enclosure comes in two styles, namely, slide-out style and cover-removable style. The slide-out rack enclosure features sliding trays which can be pulled out easily for cable management. It avoids removing the whole rack mount enclosure from the rack to gain internal access. Therefore, the slide-out enclosure is more expensive than cover-removable enclosure.

Main Rack Enclosure Types and Buying Guide

Normally, a rack enclosure is made for use in a 19-inch server rack and comes in rack units of 1U, 2U or 4U, which are the most common used types. Next are the three main rack enclosure types and their buying guidance.

1U Rack Mount Enclosure

Normally, a common 1U fiber enclosure allows for 4 x fiber adapter panels or 4 x MPO/MTP cassettes up to 96 fibers. This is the most widely used one of the common three types. Provided with a fully modular solution for a variety of fiber optic patching, terminating and splicing applications, the 1u rack mount enclosure can help you maximize rack space utilization easily.

If you want a 1u rack mount enclosure of cover-removable style, you can use it for patch cord connections with two pieces of spools. What’s more, it can hold up to 4 fiber splice trays and is available for 4 fiber patch panels or MTP cassettes. You can get more detailed usage of the cover-removable rack enclosure through the video below.

If you want a 1u rack mount enclosure of slide-out style, you can enjoy the same features that a cover-removable style have, while you have to pay more for its convenience of avoiding pulling out the enclosure cover. You can also get more information about it from the video below.

2U Rack Mount Enclosure

It is obvious that a common 2U fiber enclosure can hold 8 x fiber adapter panels or 8 x MPO/MTP cassettes up to 192 fibers compared with 1U rack mount enclosure. This rack enclosure provides you with more space for cable management since it is 1U higher than a 1U rack mount enclosure. If you have more cables to manage, you can choose this type over a 1U one. By the way, it is commonly seen in slide-out style for its height design.

4U Rack Mount Enclosure

Relatively, a common 4U fiber enclosure can hold 12 x fiber adapter panels or 12 x MPO/MTP cassettes up to 288 fibers compared with the former two rack mount enclosure types mentioned above. This rack enclosure is commonly seen in slide-out style as well.


Actually, no matter what type (1U, 2U, 4U, etc.) a rack enclosure is, it is not absolute for its capacity of how many fiber panels or cassettes it can hold. Situations vary from vendor to vendor. The rack enclosures mentioned above are the common ones provided by FS.COM. In deed, you can find other configurations from FS as well.


You may have a general understanding of what a rack enclosure is and how to choose a proper one for your cabling system. While, to build a better-managed cabling system, cable organizer is also very important. It can be used together with a rack mount enclosure to make your cables neat and uniform.