Lantronix
SISPM1040-xxxx-L3 Install Guide
33855 Rev. A
17
Installing SFP/SFP+ Modules
You can install or remove a mini-GBIC SFP/SFP+ module from an SFP/SFP+ port without having to power off the
switch.
Note
: The SFP/SFP+ ports should use UL Listed Optional Transceiver product, Rated 3.3Vdc, Laser
Class 1.
Step 1: Insert the module into the SFP/SFP+ port.
Step 2: Press firmly to ensure that the module seats into the connector.
Installing an SFP/SFP+ Module into a SFP/SFP+ Port
Installing DAC Cables
You can install or remove DAC-1m, DAC-2m, DAC-3m, and DAC-5m cables in ports 29-32.
These copper 10 Gigabit Ethernet cables comes in either an active or passive Twinax (twin axial) cable assembly
and connect directly into an SFP+ housing. An active Twinax cable has active electronic components in the SFP+
housing to improve the signal quality; a passive Twinax cable is mainly just a straight "wire" and contains few
components. Generally, Twinax cables shorter than 7 meters are passive and those longer than 7 meters are
active, but this may vary between vendors. SFP+ Direct Attach Copper (DAC) is a popular choice for 10G
Ethernet reaches up to 10 meters due to low latency and low cost.
One major application is connecting network hardware via their SFP+ interfaces. This type of connection is able to
transmit at 10 Gbps full duplex over 5 meter distances. This setup offers 15 to 25 times lower transceiver latency
than current 10GBASE-
T Cat 6/Cat 6a/Cat 7 cabling systems: 0.1 μs for Twinax with SFP+ versus 1.5 to 2.5 μs
for current 10GBASE-T specification. The power draw of Twinax with SFP+ is around 0.1 watts, which is also
much better than 4–8 watts for 10GBASE-T.
As with all cabling, one consideration point is the bit error ratio (BER). Twinax copper cabling has a BER of better
than 10−18, and thus is acceptable for applications in critical en
vironments.
Cables must not be bent below their minimum bend radius, which depends on cable size (in AWG). The table
below summarizes minimum values typical for SFP+ sustained bend radiuses:
AWG cable size Sustained bend radius
24
1.5 inches (38 mm)
26
1.3 inches (33 mm)
28
1.0 inch (25 mm)
30
0.9 inches (23 mm)
