RJ45 and RJ11

In this video from ITFreeTraining, I will look at the connector types RJ45 and RJ11. These are fundamental connector types that are used in networking and, thus, very important for the IT technician to know about.
Download the PDF handout: itfreetraining.com/handouts/ap...
Registered Jack (RJ)
0:12 To start with, I will look at the Registered Jack otherwise known as RJ. RJ is a specification that defines the jack and the connector - this is essentially the plug and the socket that it goes into.
The original RJ standard defines the number, wire position and conductors in the connector. This is something you don’t really need to know. Why? Because in IT we only use RJ45 and RJ11 as the terminology to define the plug. In IT we don’t worry about how many conductors there are, or how many wires it supports or their position, as we just use the names to refer to the plug rather than the specification. Let’s have a look at a RJ45 plug attached to a cable, and this will start to make sense.
RJ45
1:00 Let’s consider a standard network cable, which we would in IT refer to as RJ45. This particular cable, therefore, meets the standard called RJ45. This is because, in order to meet the standard, it needs to have eight positions. A position simply means somewhere a connector can be mounted to. The next requirement it needs in order to meet the standard is that it needs to have eight wires or four pairs of wires. You can see that this connector has this and, thus, meets the standard for RJ45.
Now let’s consider this cable. This cable, like before, has eight positions. However, there are only four wires or two pairs of wires being used. This connector does not meet the RJ45 standard and, technically, it should not be called RJ45. This cable does meet another RJ standard which has a different number, not 45 after it; but you will never need to know that in IT. In IT we still call this an RJ45 connector, even though, technically, it meets a different RJ specification.
Essentially, in IT, we adopted the convention of calling the connector an RJ45 connector. If there are eight wires, technically this is correct, but any less than that it is not. Don’t worry about it, if you are talking to someone in IT they will all call it an RJ45 cable; someone in telecommunications may call it by its correct name, but not in IT. Let’s now have a look at the other connection you may come across.
RJ11
2:40 The next connection that I will look at is the RJ11 connection. To be technically correct, this connector has six positions and two wires or one pair. This connector is often use to connect telephones.
If, for example, you come across a cable like the following, it has six positions, six wires or three pairs, then technically it is not an RJ11 connector, but in IT we still call it an RJ11 connector.
Before I move on in the video, I will do a quick summary of the main points to make sure everything is clear.
RJ Summary
3:16 Shown here is what we refer to, in IT, as an RJ45 connector. These are used primarily in networking, so you will see a lot of them. They have eight connectors for wires which are called positions in telecommunication language. In telecommunications, the number of wires in the connector will determine what number follows RJ. In IT, however, regardless of how many wires are used we call it an RJ45 connector.
The next connector that you are likely to come across is the RJ11 connector. A little bit smaller than the RJ45 connector, the connector itself has six connectors for wires. As before, in IT regardless of how many of these connectors have wires attached, we still call it an RJ11 connector. Although, at times, it may not be technically correct, it is a convention that we have been using in IT for a long time. If you are working in IT, you won’t need to worry. If you decide to take up a career in telecommunications, you may need to know.
Description to long for KZbin. Please see the following link for the rest of the description. itfreetraining.com/ap/1c60
References
“The Official CompTIA A+ Core Study Guide (Exam 220-1001)” Chapter 3 Position 11380-11662
“CompTIA A+ Certification exam guide. Tenth edition” Pages 809 - 811
“Registered jack” en.wikipedia.org/wiki/Registe...
Credits
Trainer: Austin Mason ITFreeTraining.com
Voice Talent: HP Lewis hplewis.com
Quality Assurance: Brett Batson www.pbb-proofreading.uk

[@Sneder]

The revelation as to why the pairs of wire are laid out how they are in RJ45 is exactly the kind of stuff why I like learning, thank you!

[@itfreetraining]

Glad to hear it. Thanks for watching.

[@FinFu509]

I love how u emphasis there is no need to dig further into those protocols as IT

[@itfreetraining]

Thanks, glad you like the video.

[@RBASB10]

Awesome video. Well explained and straight to the point.

[@itfreetraining]

Thanks very much.

[@Kid420]

That was super helpful, I thought I needed to buy an RJ11 to RJ45 adapter but it turns out an RJ11 will fit anyways!

[@itfreetraining]

Thanks, glad we could help.

[@laughingbird]

Such a great video man.. You are who i call a teacher. well done!

[@itfreetraining]

Wow, thanks!

[@sagarsuryawanshi3354]

Your Videos are very helpful for getting basic information if starting career in I.T

[@itfreetraining]

Happy to hear that!

[@LIYNSKIN]

Thanks for the video Can you please explain what is the color scheme for an rj45 to 1 pair rj11 cable?

[@engineeringinsight1338]

Thank you for the free knowledge ! much appreciated

[@itfreetraining]

Thanks for watching.

[@mRahman92]

It's actually called a 8P8C Connector and 6P4C Connectors. But like you said, this is considered semantics.

[@itfreetraining]

Thanks for information.

[@sudarshann.a.7304]

Awesome precise & sharp video

[@itfreetraining]

Thanks very much.

[@RodolfoAmbriz]

Great explanation!

[@itfreetraining]

Thanks very much.

[@mohsinshah66]

Great job. Thank you Sir

[@itfreetraining]

Thanks for watching.

[@throwaway2161]

great video, thank you

[@itfreetraining]

Thanks for watching.

[@InformationTechnology-er2wj]

Very informative, thank you.

[@itfreetraining]

Thanks for watching!

[@haichconcept9087]

I’ve learned Thanks a million

[@itfreetraining]

Thanks, glad we could help.

[@kafra2074]

Could we get another Video on the RJ45 considering the different ways to wire it considering the number of pairs? Would be really great =)

[@itfreetraining]

We are working on the new course at present and will include more ARJ45 content.

[@richardpalmer7468]

When making up RJ11 for phone do you do the color code the same positions on both ends? Because I have bought ones that were reversed from one end to the other.

[@itfreetraining]

For RJ11 they should be the same color on each end.

[@sxsphil]

Not true. they are rolled. 45 yr phone tech.@@itfreetraining

[@vinayakthote8411]

you are great man. last question can we convet rj 11 to rj 45

[@itfreetraining]

RJ11 will just plug into an RJ45 port so you don't need to. However, if you want to you could change the RJ11 connector to an RJ45 connector is you wanted to.

[@simpliciocamirino2271]

thank you for that sharing sir

[@itfreetraining]

My pleasure

[@aquibssiddiqui6387]

Is it possible to convert RJ45 broadband cable to RJ11 for old router/adsl modem? only for WIFI use........... not for telephone connection. please guide me and if there is a splitter or converter then please provide me a link. Thanks in advance!

[@itfreetraining]

To convert the cable is quite simple. If you want to convert the signal that something you are not able to do. The router will support one or the other and in some cases both.

[@saugatrgm1728]

Very nice

[@itfreetraining]

Thanks for watching.

[@gamebox3263]

can analog phone still works even if you patch it to a DATA port?

[@itfreetraining]

If you plug your analog phone into a RJ45 point it will work if you plug the other end into your PABX. If you plug the other end into a network switch it will support networking. So, it is determined by what is plugged in on the other side.

[@ashishchhetri7713]

Great 👍

[@itfreetraining]

Thanks for watching.

[@IsllamalHashimi]

Can I plug rj11 on cat6 cable for landline phone???

[@itfreetraining]

Yes. Any network cable will work with an RJ11 for a phone line.

[@1994deacon]

So you can get a cat8 rj45 but do the rj11 cables have different cat types?

[@itfreetraining]

Rj11 was designed to run telephones so only needs a very low standard of copper cable due to not much data being sent. The cat types are designed for networks which send a lot of data so a standard was required. Thus, there is no really stand for RJ11, just need some copper wire.

[@1994deacon]

@@itfreetraining but surely the rj11 cable quality will effect the overall speed of the Internet as this is literally the fist cable my Internet has to pass through before it gets to my router, then down my rj45 cables to end up in my pc. I could be missing something but it seems like it would effect it.

[@itfreetraining]

@@1994deacon Ok, so I not to clear on that one. If you are only using the RJ11 for telephone then it quality is not that important. However, if it is really bad quality this can effect the telephone. The quality not as important just for telephone calls because there is not much data being sent. If however, you are using an RJ11 connection for internet, thus sending data over it, the cable quality will have more of an effect. Having said that, you just need a good quality cable it does not need to be cat 5 or anything like that, but if it is poor quality you may have problems. I have had it before where I have had problems with the internet and replace the cable and it worked a lot better. If the cable damaged or the connection damage it can effect the signal.

[@1994deacon]

@@itfreetraining I've ordered a new cable today. Quality looked good however I was just getting confused as ethernet cables have cat types but rj11 ones don't. Got an rj11 coming with gold plated conectors so should be better than what I currently have. Also do you know if its worth shortening cables so that they are custom length fit or just spool up the excess and hide it? Not sure if exercise cable will have a noticeable effect on Internet speeds?

[@clarenzcea8897]

can you pls help me how to connect rj45 router to rj11(one pair) service provider.. need to change my old router but the problem is that it only has one pair of wiring(white blue& blue wire).

[@GitXxxd]

same here

[@itfreetraining]

A rj11 cable will plug into an rj45 port. So you can use a standard cable. However, it depends on what your rj45 port supports. Most router with an rj45 port are designed for use with an rj45 port so won't work with rj11. In order to get it to work, you would need some sort of modem to convert the rj11 (Probably phone or DSL) into rj45 (Probably Ethernet)

[@jamesnos2530]

Very good!

[@itfreetraining]

Glad you think so!

[@sharadikweli9650]

The expectation is that people in IT are dumbed down on true technical specifications. I have never heard such a 'don't worry about it' explanation!

[@itfreetraining]

It does fell like that. When the techs are installing the lines maybe they are just trying to make it simple for IT guys.

[@MrTF66]

Tnx

[@itfreetraining]

Thanks for watching.

[@bra1nsen]

How to Rj11 to USB?!

[@itfreetraining]

You are not able to that. Your best bet is to purchase a USB ethernet adapter.

[@arrowarrow6924]

main rj45 types

[@itfreetraining]

Thanks for watching.

[@technicalthug]

Plugging in an RJ11 into an RJ45 will usually damage the outer pins. Best to use an RJ45 plug int an RJ45 jack.

[@itfreetraining]

In the old days I use to this all the time and never damaged any ports. As long as you not overly forceful you should not have any problems. If you can however, I would use an RJ45 plug.

[@technicalthug]

I've seen enough bent 1& 8 pins on 8P8C jacks to know that it's generally not the case.

[@aymanla471]

you are wrong dsl connections (RJ11) use just 1 pair (2 wires) not 4

[@itfreetraining]

Huh, we make the point RJ11 standard is one pair, however in IT we incorrectly call any number of pairs in RJ11. This is incorrect.