The main elements defined in the SFP/SFP+ MSA is listed as follows:
Mechanical dimensions of the device (H: 8.5mm, W: 13.4mm, D: 56.5mm)
Transceiver edge connector to host PCB-mounted electrical connector mating
Host board mechanical layout (location/size of solder pads, etc.)
Insertion, Extraction and Retention forces
Bezel design considerations for host systems
Electrical connector mechanical aspects
Cage assembly dimensions (hollow cage mounted in host system)
Timing requirements and Status I/O
Module definition interface and data field description
Besides, the Digital Diagnostics Monitoring (DDM) feature common in many modern SFP/SFP+ transceivers as defined in SFF-8472 MSA specification. “D” in GLC-LH-SMD represents the DDM function according to the industry standard MSA SFF-8472. The SFF-8472 added DDM interface and outlined that DDM interface is an extension of the serial ID interface defined in GBIC specification, as well as the SFP MSA.
The Importance of SFP/SFP+ MSA
MSAs, like most standards efforts, are important primarily because they can give customers a choice in suppliers from which they purchase products. Freedom of choice is the foundation of the efficient operation of markets. Customers in the marketplace should have the benefit of multiple independent suppliers, each competing to gain a share of the market. This behavior forces suppliers to be as efficient and creative as possible, driving down costs and offering customers the widest array of options.
It is true that some system vendors have attempted to subvert the standardizing value of the SFP MSA or SFP+ MSA. The most common scheme is to write a unique code into some of the undefined memory in the EEPROM of each SFP/SFP+. When the transceiver is inserted into the host switch, its EEPROM is read, and, if the code is “incorrect” the module is rejected as “incompatible”. But Fiberstore can do it. At present, fiber-mart.COM offers a comprehensive brand’s compatible solution of the transceivers which can meet the demands for Cisco, HP, Juniper, NETGEAR, Brocade etc.