Hubs, Unmanaged Switches, and Managed Switches

When choosing the right industrial Ethernet switch for your network application, you should probably first ask yourself whether the switch should be an unmanaged or managed.  The information below is a brief overview of the topic.

Unmanaged Ethernet switches provide reliable "plug-and-play" Ethernet communication allowing connected Ethernet-enabled devices to communicate. Simply wire power, connect your devices, and you are done.

Managed Ethernet switches can be installed simply as "plug-and-play", but with their management functionality enabled you can secure, control and remotely monitor the network.

Users should choose managed switches when they want to:
  • Create redundancy paths to allow the network to self-heal from wiring breaks or equipment failure
  • Monitor the network and send alarms regarding network health
  • Prioritize critical control traffic over less important traffic
  • Implement access control rules and/or "lock down" the network to outside devices
  • Account for growth in size and complexity of the network

As a note, hubs (legacy equipment) function at layer 1 of the network OSI model and lack intelligence. They simply forward copies of ethernet frames to all devices connected as opposed to ethernet switches (managed or unmanaged) which efficiently forward unicast, multicast, and broadcast frames appropriately. Ethernet switches also create separate collision domains as opposed to hubs which put everything in the same collision domain. This opens the door for data collisions when devices attempt to transmit data at the same time. A final negative to note is that devices connected to a hub share bandwidth as opposed to switches which provide dedicated bandwidth for each connected device.

While it is recommended to eliminate hubs, both unmanaged and managed switches have their place. Contact Industrial Networking Solutions for advice about your unique application.

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