Type A MTP Cassette vs Type B MTP Cassette

Posted on Nov 16, 2023 by

With the rapid advancement of information technology, MTP cassettes play a crucial role in modern communication. Among them, Type A and Type B MTP cassettes are two common types of fiber cassettes, and many users may have questions about the difference between them and want to know how to choose the correct MTP cassettes. Today, this essay will answer all your questions.

What Is MTP Cassette?

MTP cassettes, also known as MPO box, are typically composed of a metal or plastic casing and refers to a modular plug-and-play box module that allows for easy connection in high-density fiber applications using MPO/MTP connectors. One side of the MTP cassette is equipped with an MTP connector, while the other side has individual fiber connectors such as LC or SC connectors. The MTP connector is pre-terminated with multiple fibers, while the individual fiber connectors are used to connect to equipment or patch cords. MTP cassettes are designed to provide efficient and flexible fiber connection solutions for data centers, telecom networks, and high-density fiber environments. Their benefits include improved cable management, reduced installation time, easy reconfiguration, and scalability. Overall, MTP cassettes offer a convenient and efficient way to manage and distribute high-density fiber connections.

Type A vs Type B MTP Cassette

Type A MTP Cassettes

Type A MTP cassettes, also known as straight-through cassettes, usually feature a straight-through wiring configuration, meaning the fiber sequence is identical at both ends. They are commonly used for connecting equipment and switch ends or for straightforward point-to-point signal transmission. The straightforward wiring of Type A is widely accepted due to its intuitive layout.

Type B MTP Cassettes

Type B MTP cassettes adopt a crossed (flipped) wiring configuration, with fiber strands reversed at the ends. In practice, they are often used for cross-connecting devices or for providing the "flip" in fiber channels to comply with different polarity requirements, especially in migrations and expansions from 10G to 40G, 40G to 40G, or higher rates.

wiring configuration

Comparative Analysis

  • 1. Polarity: The main difference between Type A and Type B cassettes lies in their polarity configurations, with Type A being straight-through and Type B being flipped. Proper polarity configuration ensures optical signals are transmitted correctly from the sender to the receiver.

  • 2. Applications: Type A is typically used for standard direct connections, while Type B is employed when fiber core inversion is required to match the polarity of the fiber optic network.

  • 3. Expandability: Although both types of cassettes can be used for expanding fiber optic networks, they have different applicable scenarios. Type B MTP cassettes are more commonly used in the expansion and migration of high-rate networks.

type A vs type B

Type A or Type B MTP Cassette?

In the market, the majority of fiber optic distribution boxes are of type A, as type A is easier to deploy, suitable for both single-mode and multimode channels, and can easily support network expansions. The biggest limitation of Class B fiber optic distribution boxes is that they do not allow the use of angled physical contact (APC) single-mode connectors. However, the selection of an MTP cassette depends on the choice of MTP cable, and the MTP cassette should be perfectly compatible with MTP/MPO connectors at both ends of the MTP/MPO cable.


In the realm of fiber networks, Type A and Type B MTP cassettes play crucial roles in different scenarios. The selection of a fiber optic cassette is crucial for the entire network system, so it is necessary to choose and connect the cassette based on standard methods. Incorrectly polarized connections may cause link failures and damage critical optoelectronic components. It is recommended for users to purchase MTP cassettes MTP cassettes from suppliers that conform to TIA standards.

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