Users Guide
Converting a QSFP or QSFP+ Port to an SFP or SFP+
Port
You can convert a QSFP or QSFP+ port to an SFP or SFP+ port using the Quad to Small Form Factor Pluggable Adapter (QSA).
QSA provides smooth connectivity between devices that use Quad Lane Ports (such as the 40 Gigabit Ethernet adapters) and
10 Gigabit hardware that uses SFP+ based cabling. Using this adapter, you can effectively use a QSFP or QSFP+ module to
connect to a lower-end switch or server that uses an SFP or SFP+ based module.
When connected to a QSFP or QSFP+ port on a 40 Gigabit adapter, QSA acts as an interface for the SFP or SFP+ cables. This
interface enables you to directly plug in an SFP or SFP+ cable originating at a 10 Gigabit Ethernet port on a switch or server.
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 configure 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 first
10 Gigabit port and you can use only that port for data transfer. As a result, only the first fanned-out port is identified 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 configure 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 configurations.
If you use an active optical cable (AOC), you can convert the QSFP+ port to a 10 Gigabit SFP+ port or 1 Gigabit SFP port. Use
the speed command to enable the required speed.
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 first 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 configurations, the following examples show the command output that the show interfaces
tengigbitethernet transceiver, show interfaces tengigbitethernet, and show inventory media
commands displays:
Dell#show interfaces tengigabitethernet 1/40 transceiver
SFP+ 1 Serial ID Base Fields
SFP+ 1 Id = 0x0d
SFP+ 1 Ext Id = 0x00
Interfaces
417