Can the smaller RJ11 jack be plugged into an RJ45 (technically a 8P8C) socket?
I've seen the plug be plugged into the socket, but have not seen it used to transmit data.
Yes it can. I have my home ADSL modem line (RJ-11) plugged into an RJ-45 socket, which goes back to my BT master socket.
They are fiddly to unplug though.
Like others have said about alignment problems, be mindful of this. The outer edges of the RJ11 cable end are thick plastic and will push the copper connectors in positions 2 and 7 down further then they are supposed to go which can cause a later issue with a RJ45 in it's place.
Yes, you could do this. You can wire RJ-45 to handle RJ-11 signals.
Personally I'd tend to look at just a few jacks with this setup as a bit unprofessional, but I've seen installations where they did everything as RJ-45 to avoid needed two kinds of connectors/cabling/etc.
Yes, can you physically plug an RJ11 jack into an RJ45 socket, as you have seen before.
Standard Cat5 cabling uses twisted pairs for pins 3&6 and 4&5 this is going to give you decent signal propagation too because RJ11 generally pairs 2&5 and 3&4.
Edit: Changed RJ11 pin numbers. I tend to forget about pins 1&6 because they aren't usually used...
Sometimes there are sockets available which fit both connectors. I had a surge protector for a while that allowed both to fit in, to supress surges on either ethernet or phone.
That said, just because you can plug an RJ11 plug into an RJ45 socket doesn't mean you should. RJ11 sockets fit RJ11 plugs. RJ45 sockets fit RJ45 plugs. Right tool for the right job. I would only try to put an RJ11 plug into an RJ45 socket if:
Yes, you can, but due to the inconsistency in getting the pins lined up, I usually end up cutting the RJ-11 end off and crimping on an RJ-45.
Cannot recommend the other way, I have had to replace RJ-11 jacks (female) where a user tried to plug in an RJ-45(male) cable. Not sure how, but he managed to get it part way inserted, and I could not get it out without damaging the receptacle.
You can plug an RJ11 plug into an RJ45 jack, but I'd make or buy an adapter in order to prevent damage and alignment problems.
By the way, in your question you use "jack" when you should use "plug". And, though "socket" works, it's more commonly referred to as a "jack".
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