You didn't try typing "gigabit switch" into eBay and looking for a cheap one?
OK
Works perfectly, just been tested.
www.ebay.co.uk
"Hub" is a problematic word in networking; back when Ethernet networks were quite primitive hubs were common. As opps said they would receive a message on one port and blat it out to all other ports. Ethernet devices like computers generally pick up only messages intended for them (bearing their address) and ignore others, so it doesn't matter if hubs blat out messages to everywhere because the filtering was largely done on the devices connected to the hub, but it fills up a network with a lot of useless messaging.
An analogy might be if you posted a letter to your friend and the local postman photocopied it 5000 times and left a copy at every house in the village. 4999 people put it in the recycling because it wasn't addressed to them and 1 opened it and read it
Nowadays we have switches, which are slightly more intelligent in that they learn the addresses of things connected to them and they can send arriving packets to ports based on the packet's address, so they generally only send packets to ports where they will eventually be picked up. This means that multiple devices can communicate more like directly, without flooding the rest of the network. An analogy is much closer to how the actual postal system operates
"Switch" as a word is like "switchboard" in old telephone nomenclature, but most people think more of like a light switch so it's not a good word for marketing departments to describe networking gear even though it it technically correct among networking nerds
Virgin choose to call your router/media center/whatever a "hub" for the marketingy fluffy "it's one place that brings everything together" meaning - it's nothing to do with a networking hub, which generally aren't sold any more
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If you want more Ethernet sockets and wifi upstairs, I would recommend you get a switch and a wireless access point (AP); you run a cable from the virgin hub to the switch, you run another cable from the switch to the PoE injector that came with the AP, and you run a third cable from PoE injector to the AP. Or you buy a switch that does PoE and connect it directly to the AP. The AP gets its power and network connection from the single network wire, but you need power on the network wire. They don't normally carry power in a home setting so that's what the PoE injector or PoE switch is for. PoE switches are more expensive than normal switches and there are different voltages of PoE so take care to match or adapt (via inline voltage changer) the requirements of the AP with the export of the switch
Example PoE injector
https://www.ebay.co.uk/itm/126165929570 and AP
https://www.ebay.co.uk/itm/314922554845
You don't make "another" wifi; you create the same network ID and security settings, as it's less headache that way- your devices will roam between the different APs on the same ID/password pairing
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You can also reuse an old ISP router for this, as long as it's wired up internally in the same way (the internal AP is connected to the internal switch) but for reasons already given in this thread I prefer dedicated kit for these things, especially when I have to tech support it