What ultimately defines the maximum throughput in a VLAN?

The maximum throughput in a VLAN is ultimately defined by the service provider infrastructure. This infrastructure encompasses the physical and logical components involved in delivering Ethernet services, including the switches, routers, and other networking elements that manage and route traffic within and between VLANs.

Service provider infrastructure determines factors such as bandwidth capacity, network congestion, and overall network design, all of which play significant roles in influencing the effective data transfer rates that can be achieved in any VLAN. Even if other factors like Ethernet frame size or Quality of Service (QoS) settings impact the efficiency of data flow, the fundamental limit on maximum throughput is established by how the network is architected and what capacities the devices within the network can support.