Channelization

Use the channelization feature to configure a single port to operate as four individual ports. Channelization can apply to the following port speeds:

• 40 Gbps (Quad Small Form-factor Pluggable) (QSFP+) — when channelized, operates as four 10 Gbps ports

• 100 Gbps (QSFP28) — when channelized, operates as four 25 Gbps ports

  

  Note

  In cases where the hardware supports it, you can insert a 40 Gbps QSFP+ transceiver in a 100 Gbps port, and use the 100 Gbps port as a 40 Gbps port. If you enable channelization on a 100 Gbps port and the switch detects a 40 Gbps QSFP+ transceiver in the port, the port operates as four individual 10 Gbps ports.

  If the switch detects a 100 Gbps QSFP28 transceiver and you enable channelization, the port operates as four 25 Gbps ports.

  To know if you can use a 100 Gbps port as a 40 Gbps port and support the channelization of that port, see the applicable hardware documentation.

You can use breakout direct attach cables (DAC) or transceivers with fiber breakout cables to connect the channelized ports to other servers, storage, and switches.

For the number of ports on the switch that support channelization, see the applicable hardware documentation.

If the product supports channelization and you enable or disable channelization on a port, the port QoS configuration resets to default values. For information about configuring QoS values, see Quality of Service.

Note

When you use channelized ports in an Split MultiLink Trunking (SMLT) configuration, the system does not display the channelized ports properly when you show MLT information for the remote port member if the remote switch runs a release that does not support channelization.

When a port is channelized, use only break out cables (copper or active optical DAC) in it. Using other cables in either a channelized port or a non-channelized port results in mismatched link status between link partners, which can lead to network issues.

Automatic Channelization

By default, ports are not channelized, which means that a port operates as one single port at the fully supported speed. The switch automatically channelizes a port if the port operates in Auto-sense mode and you insert one of the following:

• QSFP+ to SFP+ adapter

• QSFP28 to SFP28 adapter
• QSFP+ to 2xSFP+ passive or active breakout cable
• QSFP28 to 4xSFP28 passive or active breakout cable

You can also enable or disable channelization on a port manually. To disable automatic channelization on a port, you must disable Auto-sense on the port.

Note

Automatic channelization does not affect 40 Gbps and 100 Gbps SR parts; you can enable or disable channelization of ports with these parts regardless of the Auto-sense port configuration.

If you remove the existing part from an auto-channelized port, the port does not automatically disable channelization until you insert a new part that does not support channelization.

SFP-DD Ports

Note

Product Notice: SFP-DD ports are specific to 5420 Series.

Advanced Feature Bandwidth is enabled by default on the SFP-DD ports. When Advanced Feature Bandwidth is disabled, SFP-DD ports can operate as 1 Gbps ports with an SFP and as 10 Gbps ports with an SFP+. When the SFP-DD split DAC is used, SFP-DD ports can accept two SFP+ with 10 Gbps port speed.

Note

SFP-DD split DAC applies to certain 5420 Series models.

For more information about SFP-DD ports, see 5420 Series.