Small Form-Factor Pluggables (SFPs) are compact, standardised
modular, hot-pluggable, optical or electrical transceivers for
Gigabit Ethernet (1000Base-FX) or Fast Ethernet (100Base-FX).
The form factor and electrical interface are specified by a
multisource agreement (MSA). Siqura XSNet™ SFPs are
compliant with the MSA and intended to be compliant with all
other equipment that is designed according this MSA.
The XSNet™ SFPs are available in a wide range of models for
multimode or single-mode optical fiber, 100 Mb or 1000 Mb
speed rate, various distances, and one or two fibers. For reasons
of convenience, there are also two electrical RJ-45 SFPs available
(100 Mb or 1000 Mb speed rate). These are applied when an SFP
slot must be connected to an electrical cable and a few should
be available as an indispensable item during the installation of
The SFPs come in two speed grades: 100 Mb and 1000 Mb.
Though the practise of using 1000 Mb SFPs in 100 Mb speed
slots is fairly accepted - in most cases without problems - correct
functioning cannot be guaranteed as the 1000 Mb SFP design is
made primarily for 1000 Mb slots. Best practise is to use 100 Mb
SFPs in 100 Mb slots. Even if a 1000 Mb SFP can run at 100 Mb,
the combination of a 1000 Mb SFP (running at 100 Mb) and a
100 Mb SFP is NOT possible. The optical power windows (optical
transmitter output power versus minimum optical receiver input)
are totally different for 1000 Mb and 100 Mb SFPs.