Users Guide

You can use QSFP optical cables (without a QSA) to split a 40 Gigabit port on a switch or a server into four 10 Gigabit ports. To split the
ports, enable the fan-out mode.
Similarly, you can enable the fan-out mode to congure the QSFP port on a device to act as an SFP or SFP+ port. As the QSA enables a
QSFP or QSFP+ port to be used as an SFP or SFP+ port, Dell Networking OS does not immediately detect the QSA after you insert it into
a QSFP port cage.
After you insert an SFP or SFP+ cable into a QSA connected to a 40 Gigabit port, Dell Networking OS assumes that all the four fanned-out
10 Gigabit ports have plugged-in SFP or SFP+ optical cables. However, the link UP event happens only for the rst 10 Gigabit port and you
can use only that port for data transfer. As a result, only the rst fanned-out port is identied as the active 10 Gigabit port with a speed of
10G or 1G depending on whether you insert an SFP+ or SFP cable respectively.
NOTE: Although it is possible to congure the remaining three 10 Gigabit ports, the Link UP event does not occur for these ports
leaving the lanes unusable. Dell Networking OS perceives these ports to be in a Link Down state. You must not try to use these
remaining three 10 Gigabit ports for actual data transfer or for any other related congurations.
NOTE: You can use the QSA adaptor to establish connectivity between a high-density 100 Gigabit platform and a relatively
lower-end 1 Gigabit switch or a server. The QSA acts as an interface between the QSFP28 ports (that support 100 Gigabit
speeds) and SPF optics with a maximum speed of 1 Gigabit per second. Depending on the type of optics you plug into the QSA
connected to a 100 Gigabit port, the system automatically detects the supported speed of the optics and sets the interface
speed accordingly. For example, if you plug in optics that support 40 Gigabit speeds, the speed of the interface is set to 40G.
Similarly, if you plug in optics that support 1G speed, the speed of the interface is set to 1G.
Important Points to Remember
• Before using the QSA to convert a 40 Gigabit Ethernet port to a 10 Gigabit SFP or SFP+ port, enable 40 G to 4*10 fan-out mode on
the device.
• When you insert a QSA into a 40 Gigabit port, you can use only the rst 10 Gigabit port in the fan-out mode to plug-in SFP or SFP+
cables. The remaining three 10 Gigabit ports are perceived to be in Link Down state and are unusable.
• You cannot use QSFP Optical cables on the same port where QSA is used.
• When you remove the QSA module alone from a 40 Gigabit port, without connecting any SFP or SFP+ cables; Dell Networking OS
does not generate any event. However, when you remove a QSA module that has SFP or SFP+ optical cables plugged in, Dell
Networking OS generates an SFP or SFP+ Removed event.
Example Scenarios
Consider the following scenarios:
• QSFP port 0 is connected to a QSA with SFP+ optical cables plugged in.
• QSFP port 4 is connected to a QSA with SFP optical cables plugged in.
• QSFP port 8 in fanned-out mode is plugged in with QSFP optical cables.
• QSFP port 12 in 40 G mode is plugged in with QSFP optical cables.
For these congurations, the following examples show the command output that the show interfaces tengigbitethernet
transceiver, show interfaces tengigbitethernet, and show inventory media commands displays:
NOTE
: In the following show interfaces tengigbitethernet commands, the ports 1,2, and 3 are inactive and no physical
SFP or SFP+ connection actually exists on these ports. However, Dell Networking OS still perceives these ports as valid and the
output shows that pluggable media (optical cables) is inserted into these ports. This is a software limitation for this release.
Interfaces 469