If you are at all familiar with fiber optics, then you’ve probably heard of MTP® or MPO cables. But what is MTP® cable? What does MPO stand for? Is there a difference between the two? We hope to be able to answer these questions for you and more.
Let’s start by defining what an MPO is. MPOs are an abbreviation for Multi-Fiber Push On, which is a type of fiber connector.This type of connector makes it easy to connect and disconnect from adapter panels, wall plates, and other fiber couplers.
Connector MPO Structure
What makes this connector MPO so special is that it is known as a “high-density” fiber, which means that it holds multiple fibers in one cable. Whereas an LC or SC connector is just one terminated ferrule, MPOs often have 12 to 24 ferrules at their end. This maximizes server rack space and cuts down cable management because one MPO cable is the equivalent of over 12 connectors. MPOs are also very versatile as they can be found in a variety of different cable styles. MPO Patch Cables are useful when working in a server setting because they can easily be connected from one part of a server rack to another. Similarly, MPO Trunk Cables do the same thing except they can carry more information because of their double ends. Some trunk cables can even have up to six ends on one side. Finally, MPO Harness Cables make it quick and easy to split off one MPO end into multiple different SC or LC connectors.
All MPOs are built with either a male or female connector end. Female connectors can be identified by the two cable pins on the end of the connector. Female connectors are designed very similar to male connectors with the only difference being the two pins being removed with two little holes.
Another important physical feature of MPO cables is the key that helps lock the connectors in place. It’s also an important factor in connector polarity which is a topic we’ll talk about in more detail down the line.
Fiber MPO Speeds
The most important thing you should know about MPO cables is that they are able to send a ton of information at extremely high speeds. Depending on the Multimode type, an MPO cable can send at least 40G and up to 100G of information over hundreds of meters. These cables are most commonly used in big tech company server rooms or companies that need to be constantly sending and receiving large portions of data. In other words, you would never see MPO cables utilized in a home setting, at least not anytime soon.
What are MTP® Connectors?
The biggest difference between MPO and MTP® connectors is that MTP® connectors have a small little clamp which makes attachment to server racks or other MPO cables a lot more secure. MTP® and MPO are the same thing, but let me explain. MTP® connectors are a type of MPO cable which is a registered trademark of US Conec. In other words, all MTP® connectors are MPO cables, but not all MPO cables are MTP®. Kind of like how all Kleenex are tissues, but not all tissues are Kleenex; MTP® connectors are simply a brand name. At Fiber Savvy, we carry MTP® cables from US Conec but we also carry other brands of MPO cable. However, for the sake of your understanding, we will refer to MPO cables and MTP® cables interchangeably for the rest of this blog.
MPO Cabling Polarity
Another important thing to address is the polarity of the cables. Because LC and SC connectors are just one ferrule, it’s not difficult to figure out where one of the connectors needs to go. However, since connector MPOs are 12 fibers wide, you need to keep track of each light signal and where it’s going to be delivered. For this reason, there are some common polarity types that are used with MTP® MPO connectors. Use the image below as a visual reference as fiber polarity may be hard to understand. The first type of polarity is type A, or the straight type, which is where the key of the connector is up on one side and underneath the other end. The key is located on the top side of one end of the cable and on the underside of the other end. However, the fibers run straight across to the other side. Type B, also known as the reversed type, is similar to the Type A polarity with the only difference being that the key is on the top side of both of the cables. Finally, the last polarity type is Type C, or the flipped pairs type. This type of polarity swaps the pairs of each bundle of two. The end of one side also has the key on the bottom side, similar to Type A. Below you will see examples of the MTP® MPO cable polarity types.
Method Type A MPO/MTP® Trunk Cables
also referred to as straight through, connects fiber 1 in the first cassette to fiber 1 in the second cassette, following this pattern through each of the 12 fiber positions—see table 1.0 below. One end is key up and the other end is in the key down position.
Table 1.0 | Polarity Method Type A
Method Type B MPO/MTP® Trunk Cables
also referred to as cross or flipped, connects fiber 1 in the first cassette to fiber 12 in the second cassette, following this pattern through each of the 12 fiber positions, with the last being 12-1—see table 1.1 below. Both ends are in the key up position.
Table 1.1 | Polarity Method Type B
Method Type-C MPO/MTP® Trunk Cables
also referred to as cross pair or rollover, connects fiber numbers in pairs, starting with 1-2 and 2-1 on one end, 11-12 and 12-11 on the other end—see table 1.2 below for all of the fiber pairings. One end is key up and the other end is in the key down position.
Table 1.2 | Polarity Method Type C
What Can MTP Connectors be Used For?
Now we know how MPO cables are structured, how fast they can transfer data, and which polarity types are most commonly used. Now we ask, what would be a practical application for these cables? The most important thing to note is that no matter how fast data transfer speeds of a cable might be, the speed of your internet is only as capable as your switch or converter. Most homeowners and even most offices wouldn’t benefit from having MTP® MPO cables as their network setups wouldn’t be able to handle the speeds. In fact, the only businesses who would benefit from MTP® cables at this time would be large scale corporations such as Google or Apple or companies that constantly need to be sending and receiving large portions of information, like a company with a large server room.
In review, MPO connectors are a type of fiber connector that deliver better, faster speeds. MTP® cables are a type of MPO cable created by US Conec, the company that popularized the cable. We also took a look at the polarity of the MPO cables. We hope this information is helpful.