Users Guide

• The quad port must be in a default configuration before you can split it into 4x10G ports. The 40G port is lost in the configuration
when the port is split; be sure that the port is also removed from other L2/L3 feature configurations.
• The system must be reloaded after issuing the CLI for the change to take effect.
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.
NOTE: Trident2 chip sets do not work at 1G speeds with auto-negotiation enabled. As a result, when you peer any device
using SFP, the link does not come up if auto-negotiation is enabled. Therefore, disable auto-negotiation on platforms
that currently use Trident2 chip sets (S6000 and Z9000). This limitation applies only when you convert QSFP to SFP
using the QSA. This constraint does not apply for QSFP to SFP+ conversions using the QSA.
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.
• The QSA module does not have a designated EEPROM. To recognize a QSA, Dell Networking OS reads the EEPROM corresponding
to an SFP+ or SFP module that is plugged into QSA. The access location of this EEPROM is different from the EEPROM location of
the QSFP+ module.
• The diagnostics application is capable of detecting insertion or removal of both the QSA as well as the SFP+ or SFP optical cables
plugged into the QSA. In addition, the diagnostic application is also capable of reading the DDS and Vendor information from the
EEPROM corresponding to SFP+ or SFP optical cables. As a result, no separate detection of QSA is required.
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.
Interfaces
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