The main elements defined in the SFP/SFP+ MSA is listed as follows

Mechanical Interface

.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

.Labeling

.Bezel design considerations for host systems

.Electrical connector mechanical aspects

.Cage assembly dimensions (hollow cage mounted in host system)

Electrical Interface

.Pin definitions

.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.Know more:www.oemfibers.com