RJ45 cable question, conecting 2 devices

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formula400
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RJ45 cable question, conecting 2 devices

Post by formula400 »

Right, not that clued up here, but ill try and explain.

So we moved into a new build, all the bedrooms have an arial socket and an RJ45 socket, so you can plug the TV straight into the internet. guessing as wired is better than WIFI, anyways in the living room I have 1x RJ45 socket, currently I have that plugged into the BT TV box (only has 1 RJ45 in put), but id like my TV to be wired, rather than wifi (wifi is decent) not sure if there are benefits to having it wired but I think it might be more reliable and stable??


also might be handy as ill be able to connect my wahoo KICKR with a wired connecting as well,

ive had a google and can for the life of me find an RJ45 cable with 2 heads, do I get a splitter box and plug that into the wall and have one going from the TV and one from the BT box??


cheers


hope that makes sense.
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Re: RJ45 cable question, conecting 2 devices

Post by Ditchfinder »

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Re: RJ45 cable question, conecting 2 devices

Post by KungFooBob »

You need a network switch.

Something like this.

https://www.argos.co.uk/product/8495459 ... lsrc=aw.ds

You connect the socket to one port, then plug the devices into two of the other ports.
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Re: RJ45 cable question, conecting 2 devices

Post by KungFooBob »

Guess what the first google result is when you search for "5 port network switch"
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Re: RJ45 cable question, conecting 2 devices

Post by Silly Car »

I’m not sure, but you probably need a 5 port network switch, try Argos ;)
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Re: RJ45 cable question, conecting 2 devices

Post by Screwdriver »

I recommend the Netgear 5 port switch which the TP Link is trying to copy. The Netgear ProSAFE is all metal construction, unlike the injection moulded plastic copies which try desperately to look like metal.

Example: https://www.ebay.co.uk/itm/234294631172 ... Sw3ophjlM8
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Re: RJ45 cable question, conecting 2 devices

Post by Ditchfinder »

Or if you have an old network router knocking about you can repurpose that as a switch too.

https://www.howtogeek.com/174419/how-to ... rk-switch/
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Re: RJ45 cable question, conecting 2 devices

Post by Le_Fromage_Grande »

Get a switch, you can get RJ45 splitters, you'd need one at each end of the cable, as 100 Mbps uses 4 of the 8 wires in the cable, so you can use 4 wires for one connection and the other wires for the other connection, but they're a lot shit, so don't do it.
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Re: RJ45 cable question, conecting 2 devices

Post by Count Steer »

Pardon my higgerance but when you say switch, clearly it's not a physical switch, how does it split the signal/traffic so that multiple devices work at the same time?
Just interested like. :hmmm:
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Re: RJ45 cable question, conecting 2 devices

Post by Le_Fromage_Grande »

Count Steer wrote: Wed Nov 24, 2021 1:11 pm Pardon my higgerance but when you say switch, clearly it's not a physical switch, how does it split the signal/traffic so that multiple devices work at the same time?
Just interested like. :hmmm:
Each device has a network card which has a hardware address (MAC), the switch has a table of the MAC addresses and which port they're connected to and sends data for that MAC to the appropriate port.

https://en.wikipedia.org/wiki/Network_switch
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Re: RJ45 cable question, conecting 2 devices

Post by Count Steer »

Le_Fromage_Grande wrote: Wed Nov 24, 2021 1:20 pm
Count Steer wrote: Wed Nov 24, 2021 1:11 pm Pardon my higgerance but when you say switch, clearly it's not a physical switch, how does it split the signal/traffic so that multiple devices work at the same time?
Just interested like. :hmmm:
Each device has a network card which has a hardware address (MAC), the switch has a table of the MAC addresses and which port they're connected to and sends data for that MAC to the appropriate port.

https://en.wikipedia.org/wiki/Network_switch
Cheers! Makes more sense as a 'switch' rather than 'splitter' now (have actually heard of packet switching before but didn't know stuff about MACs being involved).
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Re: RJ45 cable question, conecting 2 devices

Post by KungFooBob »

Before switches were as common, hubs used to be used. They provided the same connectivity, but sent the traffic to all ports and only the device that wanted it accepted, unlike the switch that only sends it to the port with the right MAC connected.
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Re: RJ45 cable question, conecting 2 devices

Post by Count Steer »

KungFooBob wrote: Wed Nov 24, 2021 1:38 pm Before switches were as common, hubs used to be used. They provided the same connectivity, but sent the traffic to all ports and only the device that wanted it accepted, unlike the switch that only sends it to the port with the right MAC connected.
You've reminded me of a small group that used to work in some labs that I was involved with (this is going back a fair amount of time...early 80s iirc). They were a bit 'boffiny' and had this demo of various appliances (lights etc) plugged into a mains circuit. They'd send a signal via the mains supply and an appliance would go 'ahah! That's for me' and the light would come on or whatever. They were v proud and had a little model of a train carrying something for each item....but I did wonder what it had to do with gas supply. :D
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Re: RJ45 cable question, conecting 2 devices

Post by Le_Fromage_Grande »

Count Steer wrote: Wed Nov 24, 2021 1:58 pm
KungFooBob wrote: Wed Nov 24, 2021 1:38 pm Before switches were as common, hubs used to be used. They provided the same connectivity, but sent the traffic to all ports and only the device that wanted it accepted, unlike the switch that only sends it to the port with the right MAC connected.
You've reminded me of a small group that used to work in some labs that I was involved with (this is going back a fair amount of time...early 80s iirc). They were a bit 'boffiny' and had this demo of various appliances (lights etc) plugged into a mains circuit. They'd send a signal via the mains supply and an appliance would go 'ahah! That's for me' and the light would come on or whatever. They were v proud and had a little model of a train carrying something for each item....but I did wonder what it had to do with gas supply. :D
Sounds like frequency division multiplexing, ethernet over mains works via the same way, you can look it up on Wikipedia if you want to know how it works, I did a BT course on it in the late 80s, by which time it had mostly been replaced with Time Division Multiplexing, which is now also defunct.
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Re: RJ45 cable question, conecting 2 devices

Post by formula400 »

wow, never thought this would be so intense.

excuse my ignorance but what's the difference between the https://www.argos.co.uk/product/8495459 ... lsrc=aw.ds

and this

https://www.electricaldirect.co.uk/prod ... aNycGzNB70
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Re: RJ45 cable question, conecting 2 devices

Post by wheelnut »

An Ethernet cable has 8 cores, 100mbps only uses 4 of those cores, so a splitter will allow you to use the other 4 cores for a second device. You need one at both ends though.

Don’t do it that way though, get the switch below and a few of the patch leads

The switch is more of a traffic management device for the network. You need a switch.
.
Take a patch lead from the wall socket and plug it in to the switch (doesn’t matter which port). Take another patch lead and plug one end into the switch and the other end into your BT thing. Take another lead and plug it between the switch and TV.

Then another lead between the switch and any other device you want to use a wired connection for.




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Re: RJ45 cable question, conecting 2 devices

Post by formula400 »

wheelnut wrote: Thu Nov 25, 2021 5:11 am An Ethernet cable has 8 cores, 100mbps only uses 4 of those cores, so a splitter will allow you to use the other 4 cores for a second device. You need one at both ends though.

Don’t do it that way though, get the switch below and a few of the patch leads

The switch is more of a traffic management device for the network. You need a switch.
.
Take a patch lead from the wall socket and plug it in to the switch (doesn’t matter which port). Take another patch lead and plug one end into the switch and the other end into your BT thing. Take another lead and plug it between the switch and TV.

Then another lead between the switch and any other device you want to use a wired connection for.





Brilliant, thanks for that. I’ll get them ordered
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