Cat 5e, RJ45, and Telephone


Old 01-12-05, 07:32 PM
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Question Cat 5e, RJ45, and Telephone

Hello all.

I'm rather new hear, but you folks have to be the most helpful lot around. In fact, I'm so new to this forum, that this would be my first post on any internet forum. Anywho...

I'm starting a major remodel of my home. Part of that remodel is to re-wire all 2 of the existing telephone jacks and add a few more. I'm also planning to pre-wire for a whole house a/v system as well as network connectivity.

I plan on using Cat 6 cable for all the networking (RJ45) and telephone (RJ11) jacks. Now this is where I get confused and am possibly making a bigger issue out of this than it might be...

Can I use an RJ45 jack as a telephone jack? Given the different sizes, I'm guessing no. However, I ran accross a post by lilfos from '03 ( that shows a phone distribution block wired with Cat5 cable to a 12-port patch panel on the rack. The connectors there are RJ45 (as well to the other patch panels).

This is where my confusion sets in Can I have an RJ45 connector at the distribution panel and an RJ11 when I get to the wall??

Sorry for the long winded post, but I want to be sure I get all my information in Thanks in advance for your help.
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Old 01-13-05, 06:21 AM
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RJ45 jacks work fine for telephones. You can switch to RJ11 at the wall, or, as I did, just stick with RJ45 there too...

When I rewired my house shortly after buying it, I ran two Cat5 & two RG6 into a standard outlet box everywhere I wanted phones, computers, and/or Televisions. The other end of each run went to my "distribution center" (aka piece of plywood mounted to a garage wall). I terminated all of my Cat5's at the dist. center to a 24 port Patch Panel. At each jack, the two Cat5's were terminated to identical RJ45 jacks.

By running the Cat5's identically, I have more flexibility. I can make ANY of the RJ45 jacks serve either as phone or data jacks at the patch panel. Just use a Cat5 patch cable to connect a port to a switch if you want the corresponding jack to serve data, or use a phone cord to connect the port to a phone splitter if you want it to serve a phone.

If you go this route (or some variation of it), make your life easier by buying spools of Cat that are different colors, and spools of Coax that are different colors. Better yet, spend the extra bucks for Banana Peel (google that term) or similar bundled cables (to make the pulls a LOT easier).

One other thing you can do to make your life easier...instead of the standard, cheap blue electric boxes I bought, get the orange low voltage boxes that have not back...they do cost more. Or, do like my dad and I did on his house and cut the backs off the blue boxes.

Oh, and if you do use anything that requires punching down wires, buy the tool, don't use a screwdriver. The electricians at work used screwdrivers for a office trailer they wired for us, and we had much grief until we had the jacks reterminated. my turn to apologize for being long winded.

Last edited by chirkware; 01-13-05 at 06:26 AM. Reason: Clarification
Old 01-13-05, 07:56 AM
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Thanks Chirkware.

I feel like an idiot saying it this way...

If I put RJ45's at the wall what do I do with my telephone?? They are wired with RJ11 jacks. Is it as simple as replacing the RJ11 with an RJ45?

Its amazing, 110 block, punchdown, bridging... I get all that stuff. Why is RJ45 v Rj11 thing so confusing to me (maybe its better we consider that a retorical question ).
Old 01-13-05, 10:52 AM
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At the risk of simplifying this process overmuch, I will post a link to what I did in my house. I wired it with Cat5 and replaced the telephone wiring in the process with Cat5. The RJ11 plug will fit into the RJ45 outlet. Plug it in and the telephone works fine. No need to replace the plug on the telephone cord.

Here is the text of the page, for your convenience.

My application of structured wiring. 2001

My house was built in 1939. Of course, many things that we take for granted today were unheard of then. Of necessity, many changes have been made to the house over the years. Plumbing, wiring, heating and cooling have affected the way the house is used and modified. When I moved here in 2000, I wanted to be able to network my computers. We had already had the wiring changed to accommodate the needs computers have for more reliable and grounded service. I looked at wireless and wire. Wireless was still coming along and was expensive. Wiring with Cat 5 cable seemed to be the ticket. I looked at the pros and cons, and concluded that wiring the house would not be all that bad. After all, there is nothing in the attic of this house. Therefore, I had nothing to worry about as far as routing around air conditioning ducting and water heaters.

As I studied structured wiring, its hows and whys, I decided that another benefit to networking the computers would be the ability to run a telephone line anywhere I needed, via the Cat 5 cable. I could also route the television or video feeds to where needed. Although I have not yet done so, the video could be routed similarly throughout the house. We have not moved in that direction, being happy with what we have where it is.

I looked at cabling the obvious places: my wife's office, the ham radio shack. I could not decide about any other place, until it dawned on me that it may be that there will be a need for cabling in every room of the house. Since, I figured that drilling one hole was not much different from drilling several holes; and pulling one wire was not much different from pulling several wires, I made a plan.

I would run Cat 5 cable to every room in the house, except the bathroom. (More on that later). I decided that every room should have two cables, one for data and one for telephone. At least, the wiring should be there. The office was the locus of computer activity so it got 6 cables. The more I learned about structured wiring, the more I began to appreciate its benefits. I could drop a telephone line anywhere I needed. A computer could be put anywhere as needed.

Following the concept of a central wiring hub and home run wiring for the Cat 5 network, I decided to run everything to a location on the enclosed back porch of the house. There is no basement, only a crawl space. Closet space is so precious here that I would not dream of putting it in one.

I selected the locations for the outlet boxes in the rooms based upon my ability to drill an access hole from and attic and feed the cable to it and maintain distance from electrical lines and outlets.. Some of this was tempered by the individuality of the use of each room. Some was compelled by the locations of doors and windows and other such features in the rooms. The house has plaster over gyprock wall. That means that the wall sheathing is 1.25" thick I cut the box apertures in the plaster walls, then drilled the holes through the triple top plate of the walls. The triple plate is 60 year old pine. Not be confused with concrete. I had to use a brace and bit to drill the holes as my 12 volt cordless drill would not develop enough torque to cut the rock hard heart pine. The two by fours in this house are actually two by four. So the top plate was six inches of pine. Needless to say, I did not drill the holes without being sure of the proper location.

After the boxes were cut and the holes drilled, I dropped a string loop from the attic to the outlet opening for each. I used this loop to pull the Cat 5 cable gently to the box and left 18 to 24 inches at the box. The loop meant that I always had a means to retrieve the string, if I needed to redo a run. At the end, I discarded the stings. I had to extend each run to the home location at the rear of the house. I used almost all of a 1000 foot spool of Cat 5 cable. There are twenty runs of cable. I left 18 inches at the home hub location on the porch. Five feet would have been better for actual use. I ran the cable on the tops of the ceiling joist along the sides of the length of the house so that they were away from the central part of the attic to reduce the chance that they would be crushed by footsteps or items put into the attic.

Each room has at least two cables running to it. The kitchen has two outlets on adjacent walls as far apart as possible. I don't know but that someday the refrigerator will need to talk to the telephone. Anyway, the cable is there. I left out the bathroom because I could not imagine needing any connections there. Well, I believe that was a mistake. Someone mentioned that the availability of a port to wire an alert button of some sort if someone fell in the bath and could not get up or get help otherwise. This is on the to-do list.

The video cabling was not done, and nothing has been done to address wiring for the entertainment area. Later on, I suppose that I will run a set of feeds to the entertainment area and install cable amplifiers and video crossover capacity.

I borrowed and applied information from all sorts of sources and recommendations to build the network. I avoided buying the manufactured boxes and housings for networking because they were expensive, lacked flexibility, and represented overkill. Using punch down blocks avoids the needs for 8p8c terminated cables because the connections are made with the wire direct to the terminals.

I mounted a large sheet of 3/4" plywood, painted white on the wall next to the aggregation point. On this board is mounted all the components: telephone connection, telephone distribution block, DSL modem, router for network, a power strip to keep for the power supplies, punch down block for all the possible cat 5 connections imaginable, and space for future video components and wiring.

All the cables are labeled at both ends. I did this as I laid each one. I used masking tape to fold over each end and marked the tape with a sharpie indelible marker. I wanted to be sure that I did not have to trace wires anywhere. I made a chart to mount on the layout board to show the physical layout of the wires in the house as well as the labeling terminology I used for each location. That would enable someone else to understand what went where.

I abandoned the existing telephone wiring. It was a hodgepodge of modifications over many years. I pulled a run of Cat 5 to the telephone network interface device and connected the Cat 5 for the run the home run panel. This gave me a home run of telephone connection to insure the quality of the DSL signal. Similarly, one would run the primary cable connection for cable internet service to have the peak signal to distribute from the hub.

Here is a photograph of the hub panel. I shows all the equipment at a glance. I used a velcro strap to mount the DSL modem and router to the panel. I constructed a vented cover to hang over all this so that it is out of sight. The cover is open and the top and bottom to allow for convection cooling.


Here is a view showing the cabling coming out of the wall through an open backed wiring box. It is more crowded than I thought it would be. It would have been better to use a larger box to pass the cabling through. I was faced with having to come through the wall to this point because I wanted to provide the protection of the wall enclosure to protect the cabling. As luck would have it, the location for the box is between two studs about nie inches apart. I got lucky on the location for this box.


This is a view of the wiring for the line from the telephone company to the punch down distribution. The telephone runs straight here from the outside. The individual telephone lines for the house punch down into the block and into the network distribution to provide dial tone on the 8p8c wall jack. The traditional RJ-11 telephone connector standard on a telephone line plugs into the 8p8c wall jack and the dial tone is available on the appropriate pins.


The telephone comes in from the upper left to supply the blue and white wires in the punch down block. The individual taps are punched down from the punch down blocks applied over the underlying wiring to feed the block itself. The tap at the upper row runs to the DSL modem.

Although there is quite a bit of extra cable involved, the telephone loops around at the top of the panel. I learned from wiring the network in the house that it was a mistake to have the wires too short. You cannot add to them. This forced me to have the feed from out of the wall come in to the side of the panel and offset everything from the original plan because the cables were not long enough.

Here is a shot of the router as mounted with feeds into it. I have a hub to augment the router, if need be. The hub uplinks to the router to provide more connections. Currently there are three computers on the network. At times, there have been as many as five. Given sufficient connections, the router can support up to 254 devices simultaneously. A router provides some protection for the network through a sort of Network Address Translation, preventing someone from looking into the network address and seeing the actual computers.


This is a closer shot of the feeds from the individual rooms connecting to the punch down block and from there to patch cords punched down with 8p8c connectors on the other ends to connect to the router.


Individually, the components included: Cat 5 cable - approximately 1000 ft, 8p8c connectors, crimping tool for connectors, 8p8c wall receptacles to mount on the cable, mounting/face plates to support the receptacles in the wall box, 110 block for 100 pr wiring with legs, 110 punchdown tool, c-4 blocks to mount over the wiring on the 110 punch down blocks whereon to punch down the leads to the router and telephone connections, masking tape for tags on wiring itself, cable ties to restrain the cable, adhesive cable ties to mount cable on the board. I skipped the tool to mount the c-4 blocks. It was $200 and I thought I would fake it with the 110 punchdown tool. It worked.

All in all, I have been happy with the network that I built. There is much more detail to it than is covered in this article. This is a look at what it is. If you want any more information how I put all of this together, drop me an e-mail at [email protected]

Hope this helps.
Old 01-13-05, 12:57 PM
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Originally Posted by dewmyster
If I put RJ45's at the wall what do I do with my telephone?? They are wired with RJ11 jacks. Is it as simple as replacing the RJ11 with an RJ45?

Sorry, I should have mentioned that...Just plug the phone directly into the RJ45 port. An RJ11 end will plug in to an RJ45 port just fine. There's no need to do any modifying. Just plug it in.

The link from the thread you referenced is a good example of a home brewed distribution center, though it is more elaborate than necessary.

I'll try to take a few pictures of my setup this weekend and post links to them. Basically, its just a 2x2 foot board mounted on the wall with a 24 port patch panel, a couple of cable splitters, and a double RJ45 jack with the phone line running through it. Throw in a a cable (or DSL) modem & a broadband router and you are set. The 2x2 board just gives you an easy way to mount everything to the wall. Just be sure power is available to the board, as you will want to put a surge protector there to power the modem and router.

I'll also try to take a shot of a "spider cable" which I created to distribute dial tone to the appropriate jacks. Then I'll try to explain what to do with them. This link shows what a spider cable does, though they are using it for a different purpose:

Spider Cable

Now you've got me wanting to set up a "How I did my structured wiring" web page. LOL
Old 01-25-05, 04:33 PM
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Thanks, again!!!

Chirkware & Chris,

Sorry for the long delayed "thank you" for the information. Work (my real job, not all the remodeling that I'd love to be my real job) has been a nightmare.

The project websites are great learning tools for me. Relating the text and concepts to the physical implementation clear up a lot of questions. I've been taking pictures of my entire project and will include the structured wiring stuff. Hopefully, I'll finally be able to get my website together and "chronicle" this home improvement saga

The information on the spider cable cleared my RJ45 - RJ11 question right up. No more confusion here.

Thanks again for all the information. You folks rock.
Old 02-10-05, 08:42 AM
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Great info, but I have to say I am still a bit confused and hope you can clarify for me.

I am wiring my basement, including RG6, Cat 6, and Audio (14 guage speaker wire).

I have Verizon DSL which is great. I would like to distribute this throughout the basement, in addition to handling the existing phone jacks throughout the house. My DSL setup includes the modem with a direct connect port and a Lynsys wireless access point/router that can alos be connected to the modem.

With Verizon, there is also filter placed in-line at the phone jack between the phone and the jack for plain old telephone service. (Of course this is not done when connecting to the modem.)

So, when wiring the home-run location/wire closet in the basement, I plan to bring the Cat 3 to this spot, then split to phones (Cat 3) and DSL modem (Cat 6). The DSL modem would then link to the wireless router access point.

If I put a filter in line here on the phone distribution side, but not the DSL line, will that mean I can eliminate the filters throught the house at the voice phone jacks?

Not sure I want to do this, but am considering it. For the basement I could wire all of the jacks to include a voice-only RJ45 and a a data RJ45. Then I would be able to use any one of the data RJ45 jacks as a direct connect to the DSL modem (location could be changed via patch panel) or I could add a router and have all basement locations DSL-accessible. Wireless access to DSL would only be necessary upstairs in this last case.

Am I thinking correctly? Will this work? Is there a simpler solution? How did you handle the voice filter?

Old 03-03-05, 08:23 AM
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just hook your t&r on the pin 4 & 5 of the RJ45... or look at the colors on the jack and put you tele line on the g & r markings.. you'll see things like w/b, b, w/o, o, w/g, g, w/brn, brn, and g, r... your ethernet connections will be made on pairs 1, 2, 3, 6.... T1 for those that use it, are on 1, 2, 4, 5...
and personally, when I make up an ethernet cable, I do not split pairs.. I lay them in the modular so as to use pairs 1 & 2 on my pins 1,2,3 & 6... organize the wires like b/w w/b o/w g/w w/g w/o w/brn brn/w I realize the reversals, but when you lay down wires on the jack, pin 1 is the R lead, 2 is the T lead, 3 is the R lead, and 6 is the T lead.. most cables you buy just lay the pairs along side each other in order.. they split the 3 & 6 doing this..
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