Multi-Source Agreement: A Beginner Guide

Initial Published: August 21, 2024

When it comes to the optical transceiver and cables, we should take a look at the vendor’s key specifications table. One crucial benchmark is the Multi-source agreement. But what is it?

In this blog, we will focus on the MSA and introduce general information for beginners. We’ll also collect most transceiver MSAs and make a complete guide list, trying our best to help you find them all in one place.

Let’s dive in and explore together!

What is a Multi-Source Agreement

The multi-source agreement, short for MSA, is a multi-vendor specification defining the transceiver form factors and the management interface for seamless communication interface interoperability.

In most cases, Multi-source agreements (MSAs) do not represent official standards organizations. Instead, they are loose organizations composed of many leader transceiver vendors, equipment manufacturers, and industry contributors.

By making and publishing the agreements, all industry suppliers can follow the same basic specifications. That allows all vendors and manufacturers to follow the MSA agreement, resulting in transceivers and modules that are interoperable and compatible with each other, even if they come from different vendors.

The multi-source agreement usually defines the following aspects:

Form factors (Ex. Package Dimensions, Pinout)
Electrical Interface
Optical Interface
Cage and Connector Assembly Dimensions
Management interface

SFP MSA

Let us take the INF-8074i as an example. It is the basic SFP MSA and defines the specifications below.

SFP Transceiver Package Dimensions
Mating of SFP Transceiver PCB to SFP Electrical Connector
Host Board Layout
Insertion, Extraction, and Retention Forces for SFP Transceivers
Labeling of SFP Transceivers
Bezel Design for Systems Using SFP Transceivers
SFP Electrical Connector Mechanical Specifications
SFP Cage Assembly Dimensions

Multi-Source Agreement List

Since multiple organizations publish many different transceiver MSAs, it can be very troublesome for the demander to collect the complete list of MSAs. That is why we created this compressive Multi-Source Agreement guide list.

In this simple but complete list, you can check the primary MSA’s detailed information, including name, revision, published date, responsible organization, and targeted application. Most importantly, you can download the released MSA documents in one place instead of visiting different websites for multiple agreements.

Series	MSA Name	Release Date	Revision	Type	Title	Application	Organization
SFP/SFP+	INF-8074i	2001-05-12	1.0	Form factor	SFP (Small factor pluggable) Transceiver	SFP Module, SFP Connector SFP Cage, SFP Port	SFF Committee
SFP/SFP+	SFF-8431	2013-09-15	4.1	Form factor	SFP+ 10Gb/s and Low-Speed Electrical Interface	SFP+ Module, SFP+ Connector SFP+ Cage, SFP+ Port	SFF Committee
SFP/SFP+	SFF-8432	2018-11-30	5.2a	Form factor	SFP+ Module and Cage	SFP+ Module, SFP+ Connector SFP+ Cage, SFP+ Port	SFF Committee
SFP/SFP+	SFF-8472	2023-08-03	12.4	Management	Diagnostic Monitoring Interface for Optical Transceivers	SFP/SFP+/GBIC Module	SFF Committee
SFP/SFP+	SFF-8079	2005-02-02	1.7	Management	SFP Rate and Application Select	SFP Module, SFP Connector SFP Cage, SFP Port	SFF Committee
SFP/SFP+	SFF-8089	2005-02-03	1.3	Management	SFP Rate and Application Select	SFP Module, SFP Connector SFP Cage, SFP Port	SFF Committee
SFP/SFP+	SFF-8690	2024-05-20	1.5	Management	Tunable SFP+ Memory Map for ITU Frequencies	Tunable transceiver	SFF Committee
SFP/SFP+	SFF-8024	2024-07-09	4.12	Management	SFF Cross Reference to Industry Products	SFP/SFP+/SFP28/QSFP/QSFP28 Module SFP-DD/QSFP-DD/OSFP Module	SFF Committee
SFP/SFP+	SFF-8419	2022-01-14	1.3	Management	SFP+ Power and Low Speed Interface	SFP+ module	SFF Committee
SFP/SFP+	SFF-8402	2022-12-21	1.2	Form Factor & Management	SFP+ 1X Pluggable Transceiver Solutions	SFP+ (4 Gb/s), SFP10, SFP16, SFP28, SFP56, and SFP112	SFF Committee
SFP/SFP+	DSFP MSA	2018-09-18	1.0	Form Factor & Management	Dual Small Form Factor Pluggable Module	DSFP	DSFP MSA
SFP/SFP+	CSFP MSA	NA	NA	Form Factor & Management	Compact Small Form-Factor Pluggable	Compact SFP	CSFP MSA
XFP	INF-8077i	2005-08-31	4.5	Form factor & Management	10 Gigabit Small Form Factor Pluggable Module	XFP Module, XFP Connector XFP Cage, XFP Port	SFF Committee
XFP	SFF-8477	2009-12-04	1.4	Management	Tunable XFP for ITU Frequency Grid Applications	Tunable XFP Module	SFF Committee
X2	X2 MSA	2005-04-07	2.0	Form Factor & Management	X2 MSA	X2 Module, X2 Connector X2 Cage, X2 Port	X2 MSA
XPAK	INF-8475	2002-12-05	2.2	Form Factor	XPAK Small Formfactor Pluggable Transceiver	XPAK Transceiver, XPAK Connector	SFF Committee
Xenapk	INF-8474	2002-09-18	3.0	Form Factor	Xenpak 10 Gigabit Ethernet Transceiver	Xenpak Module, Xenpak Connector Xenpak Cage, Xenpak Port	SFF Committee
CFP	CFP MSA	2010-06-07	1.4	Form Factor	CFP MSA Hardware Description	CFP Module, CFP Connector CFP Cage, CFP Port	CFP MSA
CFP	CFP2 MSA	2013-07-31	1.0	Form Factor	CFP2 Hardware Specification	CFP2 Module, CFP2 Connector CFP2 Cage, CFP2 Port	CFP MSA
CFP	CFP4 MSA	2015-03-18	1.1	Form Factor	CFP4 Hardware Specification	CFP4 Module, CFP4 Connector CFP4 Cage, CFP4 Port	CFP MSA
CFP	CFP8 MSA	2017-03-17	1.0	Form Factor	CFP8 Hardware Specification	CFP8 Module, CFP8 Connector CFP8 Cage, CFP8 Port	CFP MSA
CFP	CFP MSA	2017-03-24	2.6	Management	Management Interface Specification		CFP MSA
QSFP	SFF-8436	2018-08-31	4.8	Form Factor & Management	QSFP+ 10 Gbs 4x Pluggable Transceiver	QSFP+ Module, QSFP+ Connector QSFP+ Cage, QSFP+ Port	SFF Committee
QSFP	SFF-8665	2024-07-09	1.9	Form Factor	QSFP+ 28 Gb/s 4x Pluggable Transceiver Solution	QSFP28 Module, QSFP28 Connector QSFP28 Cage, QSFP28 Port	SFF Committee
QSFP	SFF-8636	2023-01-03	2.9	Management	Management Interface for Cables Environments	4-channel pluggable transceiver and 4-channel managed external cable	SFF Committee
QSFP	SFF-8661	2018-06-22	2.5	Form Factor	QSFP+ 4X Module	QSFP+ 4X Module	SFF Committee
QSFP	SFF-8635	2015-06-29	0.6	Form Factor	QSFP+ 4X 10 Gb/s Pluggable Transceiver Solution (QSFP10)	QSFP10 Module	SFF Committee
Other	SFF-8086	2018-08-31	2.6	Form Factor	Mini Multilane 4X 10 Gb/s Common Elements Connector	Mini Multilane Connector	SFF Committee
Other	SFF-8081	2014-09-13	1.4	Form Factor	SFP+ 1X 16 Gb/s Pluggable Transceiver Solution (SFP16)	SFP10 Module, SFP10 Connector	SFF Committee
GBIC	SFF-8053	2000-09-27	5.5	Form Factor	GBIC (Gigabit Interface Converter)	GBIC Module, GBIC Connector GBIC Cage, GBIC Port	SFF Committee
SNAP12	SNAP12 MSA	2002-05-15	1.1	Form Factor	12-channel optical pluggable module	Multi-fiber parallel optics. Superseded by CFP and CXP	SNAP12 MSA
QSFP-DD	QSFP-DD MSA	2024-06-25	7.1	Form Factor	QSFP-DD/QSFP-DD800/QSFP-DD1600 Hardware Specification for QSFP DOUBLE DENSITY 8X PLUGGABLE TRANSCEIVERS	QSFP-DD/QSFP-DD800/QSFP-DD1600 Module and Connector	QSFP-DD MSA
QSFP2	SFF-TA-1027	2024-07-13	1.0	Form Factor	QSFP2 Connector, Cage, & Module Specification	QSFP2 Cage, Connector & Module	SFF Committee
OSFP-XD	OSFP-XD MSA	2023-03-17	1.0	Form Factor	OSFP-XD, OCTAL SMALL FORM FACTOR eXtra Dense PLUGGABLE MODULE	OSFP-XD Module, connector and cage systems	OSFP-XD MSA
OSFP	OSFP MSA	2022-10-02	5.0	Form Factor	OSFP OCTAL Small Form Factor Pluggable Module	OSFP&OSFP1600 Module, connector and cage systems	OSFP MSA
LPO MSA	LPO MSA	NA	NA	Form Factor	Linear Pluggable Optics	LPO Module	LPO MSA
OpenZR+	OpenZR+ MSA	2023-07-28	3.0	Form Factor	Open ZR+ MSA Technical Specification	400G OpenZR+ solution	OpenZR+ MSA
PON	25GS-PON MSA	2023-11-02	3.0	Form Factor	25GS-PON Specification 25 Gigabit Symmetric Passive Optical Network	25GS-PON	25GS-PON MSA
PON	ITU-T G.987	2012-06-13	3.0	Form Factor & Management	10-Gigabit-capable passive optical network (XG-PON) systems	XG-PON	ITU-T
Terabit BiDi	Terabit BiDi MSA	2023-01-26	1.0	Form Factor & Management	800G-VR4.2, 800G-SR4.2, 1.6T-VR8.2, and 1.6T-SR8.2 Multimode Fiber Technical Specifications	800G-VR4.2, 800G-SR4.2, 1.6T-VR8.2, and 1.6T-SR8.2 Module	Terabit BiDi MSA
100G Lambda	100G Lambda MSA (100G-FR &100G-LR)	2018-09-18	2.0	Form Factor & Management	100G-FR and 100G-LR Technical Specifications	100G-FR and 100G-LR Module	100G Lambda MSA Group
100G Lambda	100G Lambda MSA (400G-FR4)	2018-09-18	2.0	Form Factor & Management	400G-FR4 Technical Specification	400G-FR4 Module	100G Lambda MSA Group
100G Lambda	100G Lambda MSA (100G-LR1-20,100G-ER1-30,100G-ER1-40)	2021-06-29	1.1	Form Factor & Management	100G-LR1-20,100G-ER1-30,100G-ER1-40 Technical Specifications	100G-LR1-20,100G-ER1-30,100G-ER1-40 Module	100G Lambda MSA Group
SFP-DD	SFP-DD MSA	2023-10-27	5.2	Form Factor & Management	SFP-DD/SFP-DD112 Hardware Specification for SFP Double Density Pluggable Transceiver	SFP-DD/SFP-DD112 Module, connector and cage systems	SFP-DD MSA
QSFP112	QSFP112 MSA	2022-10-11	2.1.1	Form Factor & Management	Quad Small Form Factor Pluggable Module 112	QSFP112 Module, connector and cage systems	QSFP112 MSA
General	Common Management Interface	2021-11-02	5.2	Management	Common Management Interface Specification (CMIS)	QSFP-DD, OSFP, COBO, QSFP	Optical Internetworking Forum (OIF)
ELSFP	ELSFP MSA	2023-08-23	01.0	Form Factor	External Laser Small Form Factor Pluggable (ELSFP) Implementation Agreement	ELSFP Module	Optical Internetworking Forum (OIF)
CPO	CPO MSA	2023-03-29	01.0	Form Factor	Implementation Agreement for a 3.2Tb/s Co-Packaged (CPO) Module	3.2T Co-Packaged Module	Optical Internetworking Forum (OIF)
400ZR	400ZR	2022-11-03	02.0	Management	Implementation Agreement 400ZR	400G-ZR Module	Optical Internetworking Forum (OIF)
CWDM4	CW-WDM MSA	2021-06-04	1.0	Management	CW-WDM MSA Technical Specifications		CW-WDM MSA
CWDM4	CWDM4 MSA	2015-11-23	1.1	Management	100G CWDM4 MSA Technical Specifications	100G CWDM4 Module	CWDM4 MSA

Table 1: Multi-Source Agreement List

MSA FAQs

Q: What is an MSA transceiver?

A: Simply put, an MSA transceiver means the optical module complies with one or multiple multi-source agreements. In contrast, it is called a Non-MSA transceiver. Nearly all the transceivers follow the MSA standards for seamless performance on different brands’ equipment.

Q: What is an MSA SFP module?

A: In most cases, the MSA SFP module refers to the SFPs manufactured per the industry MSA agreements. However, sometimes, the IT guys may use it to refer to the generic SFP, which is different from the compatible SFP.

Q: Will the MSA-compliant SFP work in Cisco, Juniper, and HPE brand switches?

A: The quick answer is “NO.” Though the SFP port in all brand switches requires the MSA-compliant SFP module, the opposite is invalid. Because most of the leading brands, including Cisco, Juniper, and HPE, lock the SFP port to prevent third-party SFPs from working correctly.

Therefore, only the MSA-compliant SFP with a unique code can work with those switches.

Conclusion

You should now know about the general transceiver Multi-Source Agreement (MSA). MSA ensures seamless interoperability and compatibility of optical transceivers and modules across various vendor platforms. Following the same MSA standards, the industry vendor, manufacturer, and end users can choose the suitable transceiver for diverse networking equipment.

One thing to remember: As technology evolves and needs escalate, some MSAs become outdated, stop upgrading, and cease to be used. The most common examples are XPAK, X2, Xenpak, and GBIC MSAs.

However, others (like INF-8074, SFF-8472, and SFF-8431) are still popular and important in the telecom and datacom industry. We will also put one eye on it and regularly upgrade this blog to keep it fresh.

Do you know any other MSA missed?

If you have any further questions, leave a comment below.

Reference

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Optical Networking, Optical Transceiver