This is the actual negotiated link speed currently in effect across the member ports of this LAN uplink port-channel. Comparing this operational value against adminSpeed on the same row is how an admin catches a member port that negotiated down to a lower speed than configured, which would silently reduce the bundle's total throughput without taking the port-channel itself down. If adminSpeed reads '10gig' but this field reports a lower rate, one of PC-1280's four members likely has a bad transceiver dragging down its portion of the bundle.