What are SFP MSA and SFP+ MSA standards?

Small Form-factor Pluggable (SFP) Transceiver MultiSource Agreement (MSA)

We often hear the familiar terms SFP, QSFP28, QSFP-DD, and other optical module package types concerning fiber optic modules.

Who defines the standards for these optical modules? What are the specific measures for optical modules? Today AOA Technology will talk about the MSA standards for optical modules.


What is the MSA standard for optical modules?

In the specifications of each manufacturer’s optical module, you will often see “MSA compliant”. The MSA stands for Multi-Source Agreement and is an agreement between multiple manufacturers to implement standards for optical modules. They are designed to provide the same basic functionality and operability across different suppliers and companies. 

The IEEE (Institute of Electrical and Electronics Engineers), the world’s largest professional technical organization, has established standards for optical modules. However, the interface types of optical modules from different manufacturers became diverse at one time. To solve the incompatibility problem and lack of operability, several manufacturers joined together to form an organization to standardize the interface types, functions, and installation of optical modules, resulting in the MSA protocol, which complements the IEEE standard. So MSA has now become a recognized standards organization in the optical communications industry, but it is not an official organization.

The MSA standard defines the dimensions of optical modules, the electrical interface of optical interfaces, and other standards. Take SFP MSA as an example, the most common SFP optical module in the market; its specifications are not standardized by any official standards body but by SFP MSA. MSA-compliant products include optical modules, fiber optic patch cords, and other networking products.


What are the MSA-compliant optical modules?

The MSA has helped accelerate the development of optical modules such as SFP, SFP+, CFP, and QSFP over the past two decades, enabling them to support higher-speed bandwidths such as 100G, 400G, etc. Below is a list of the basic specifications defined by the SFP MSA.


Mechanical Interface

l SFP Transceiver Package Dimensions

l Mating of SFP Transceiver PCB to SFP Electrical Connector

l Host Board Layout

l Insertion, Extraction, and Retention Forces for SFP Transceivers

l Labeling of SFP Transceivers

l Bezel Design for Systems Using SFP Transceivers

l SFP Electrical Connector Mechanical Specifications

l SFP Cage Assembly Dimension

l Dust / EMI Cover


Electrical Interface

l Pin Definitions

l Timing Requirements of Control and Status I/O

l Module Definition Interface and Data Field Description

AOA Tech_SFP Module Features


What are the common optical module MSA standards?

SFF-8079: SFP Rate and Application Selection

SFF-8089: SFP (Small Formfactor Pluggable) Rate and Application Codes

SFF-8418: SFP+ 10 Gb/s Electrical Interface

SFF-8431: SFP+ 10 Gb/s and Low Speed Electrical Interface

SFF-8432: SFP+ Module and Cage

SFF-8472: Diagnostic Monitoring Interface for Optical Transceivers

INF-8074: SFP (Small Formfactor Pluggable) Tansceiver

INF-8074i: SFP (Small Form Factor) Transceiver

INF-8077i: 10 Gigabit Small Form Factor Pluggable Module (XFP MSA)


Why is the MSA standard necessary for optical modules?

Since MSA has set a uniform standard for optical modules, the optical module manufacturers follow MSA standards for development and production when designing their systems to ensure interoperability and interchangeability between optical modules provided by different companies. The following discusses the importance of MSA standards for optical modules from three aspects.


  • More choices.

The MSA standard provides a variety of options for end users. There are many different brands of module suppliers, but as long as the modules are MSA-compliant, they have the same form factor and size. Various suppliers provide optical module products with the same features and dimensions, so users are not constrained by a single brand and have more choice and bargaining power. In short, as long as these optical modules comply with MSA standards and have good compatibility, customers can choose any optical module they need from any third-party supplier. Still, here it is important to note that the code of the module and the switch should be compatible.


  • Lower cost.

For large network setups (especially data centers), the number of modules used is huge; controlling the cost of module procurement is an essential factor. In some ways, the MSA standard prevents the optical module market from being monopolized by certain mainstream manufacturers. Many suppliers using the MSA standard must compete with each other to win a share of the optical module market, a situation that helps reduce the cost of building networks for end users.


  • Better development of technology and products.

The result of MSA standards is to break the market’s uncontrolled growth. Under the same standard, it is more conducive to global research and development and upgrading optical module products. Reduce the waste of resources caused by different standards.

AOA Tech-Optical SFP Module Packing


If you are interested in the MSA standard, you can contact us, and we can send the MSA standard file to your email.


For more information about SFP modules, click the following link to view them.


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