phone jacks and cat5 ?

Discussion in 'Computing and Networks' started by Mathematics!, Feb 4, 2010.

  1. Mathematics!

    Thread Starter Senior Member

    Jul 21, 2008
    1,022
    4
    My new house has phone jacks with 6pins in them
    My old house had phone jacks that where 4 pin jacks

    All my phone cords I use for telephone use 4pins green , red , yellow , black... really only ( the green and red because the yellow and black is for a second line that I don't have)

    I am wondering if the old 4pin rj11 connectors can be plugged into/used on the 6pin RJ11 wall jacks.... like are they backwards compatible???

    Also question 2
    I have always used 66blocks for connecting alot of phones together I found that they are less of a hassel then using telephone splicers.
    But my question is I have been installing cat5 rj45 jacks in all the rooms so everybody will have the ability to get internet in there room...
    But I am wondering can I just connect all the cat5 wires together on part of the 66 block and then from that to the cable modem /router...
    Or must each cat5 wire be connected to a distinct port on the router...

    I think they have to be connected to distinct ports of the router to be given a different ip address for each computer...

    But wondering what would happen if you didn't use a router and just wired all the cat5 from each room together on a 66block and then had a main cat5 wire running from the 66block to the cable modem?

    Would everybody get internet would every body get assigned the same ip address since their on the same line?

    Thanks because it would be nice not to have to run all of the rooms cat5 wires back down to the router and plug them into distinct ports all the time. When I am stringing wire sometimes it makes the run twice as long to get back to the router/cable modem room with it....

    Also question 3
    I would like to know how big busniess do the cat5 wall jacks I would think running all the wires to a router would be not possible..... I have only seen router/switches with a specific amount of port say 120 or so what happens if the building had more then 120 rj45 jacks then how would they do it? Their must be a way they can easyly add on an unlimited amount of ports???
     
    Last edited: Feb 4, 2010
  2. retched

    AAC Fanatic!

    Dec 5, 2009
    5,201
    312
    You can daisy chain each bank to the next bank and so on.

    attached is the back side of a typical switch setup.
    and take a look at this huge business setup on pic 2
     
  3. Mathematics!

    Thread Starter Senior Member

    Jul 21, 2008
    1,022
    4
    I am unsure what you mean
    In picture one is this a router?

    And in picture 2 are these pink wires all cat5 wires It is hard to make out weather they have rj45 connectors on them or not... They look like sideways long 66 blocks but do these contain have rj45 jacks on them or are these wires directly screwed onto terminals...cann't tell in pic.

    Thanks

    Also is those rj11 6pin jacks backwards compatible with rj11 4pin jacks for the telephone?
     
  4. AlexR

    Well-Known Member

    Jan 16, 2008
    735
    54
    Q1. 6pin RJ11 sockets are backward compatible with 4 pin RJ11 plugs and you can even buy masking plates that fit into the 6 pin socket and effectively turn it into a 4 pin unit.
    Strictly speaking you don't the masking plate, they are designed so that you can plug a 4 pin plug into a 6 pin socket but the masking plate makes it neater.

    Q2. You must wire each RJ45 socket back to its own ports on your router or switch. Cat5 cables must not be commoned together. If you did common up the cables and take them to a singles router port you would end up with no-one receiving anything because the router would not be able to establish a link.

    Q3. Business usually have a distributed system of routers and switches. There will be one or two large switches on every floor of a building (or sometimes every 2nd floor so that each switch services 2 floors). Every data outlet on that floor will connect via cat5 cable to a port on the floor switch. The floor switches are in turn linked by fibre optic to the main switches and routers in the building data centre.
    Ethernet switches do come with a lot more than 120 ports. Using switches with 250 ports per floor is common but if you need them you can get switches that support over 1000 ports.
     
  5. Mathematics!

    Thread Starter Senior Member

    Jul 21, 2008
    1,022
    4
    Ok , I only have a question about this got you on everything else
    So will the 4pin telephone cord plug directly into the 6pin jack or must you first use a masking plate before using it with the 6pin jack?

    Question 2
    Could you use a RJ45 jack as an RJ11 phone jack?
    What I mean by this is if I connected the correct wires/pins of the RJ45 jack to the telephone lines could you plug a telephone RJ11 into the This jack.

    Or at least I would think it would work if I made a telephone cord with one side of the cord with an RJ45 (for wall connection) and the other side RJ11 jack (for the phone connection )

    Now that I think about it why do we have 2 seperate connectors/jacks for phone and computer.... Is the 4pins not enough for the computer data being send to the router do the 8pins on the RJ45 jack all get used when connecting to internet ,...etc. If so then I see why we have 2 different jacks for the phone and computer but if the computer is only using 2 reciever/transmitter pairs then they would only need 4 pins....?
    Either way seems that if you cann't do that then maybe the phones should just use RJ45 jacks and get rid of the RJ11 jacks no reason to have 2 seperate jacks.....

    And if people where confused about which jack is a telephone or computer jack a simple lable on the plate could indicate it (or a color code plate or something)

    Or if that didn't work you could just plug it in and if you don't here dial tone then you know that it must be a computer jack...

    Thanks for all your help
    I am pretty much all set
     
  6. BMorse

    Senior Member

    Sep 26, 2009
    2,675
    234
    they sell wall outlets equipped with cat5, phone and cable all in one unit, you can probably find them at your local home remodeling store (Lowes, or Home Depot....).... some even have a 2 outlet ac plugins too, so you can have everything terminated neatly in the j box....


    also here is the pinout for cta5 connections >>> http://pinouts.ru/Net/Ethernet10BaseT_pinout.shtml
     
  7. Mathematics!

    Thread Starter Senior Member

    Jul 21, 2008
    1,022
    4
    So in your link cat5 pinout looks to only use 4pins of the 8pins.
    So why do we have 8wires in the cat5 cable if we only ever use 4 wires??? I know for phone lines the other nonused wires are for a seperate line or fax but don't get why the extra 4 are reserved on the cat5 wire when it comes to computers/data?

    I have made crossover cables and regular RJ45 cables but I always put all the wires into the connectors but if their are 4 wires that aren't used I should beable to make the same RJ45 cables be following the pinout and not connecting the nonused wires to the pins at all???

    Also I understand they see wall plates to do everything I want but I am just curious about my posted questions (not saying I am going to do it this way)

    Thanks
     
  8. AlexR

    Well-Known Member

    Jan 16, 2008
    735
    54
    Because the Ethernet utp standard was developed to cover all foreseeable eventualities. It reserves one pair for send data, one for receive data, one for collision detection and a pair for power. The fact that if you use a switch rather than a hub you don't need collision detection and that most devices supply their own power does not alter the fact the the standard says that there will be provision for those functions so the connectors must have 8 pins.
    Not a good idea. Its just as easy to connect the 8 wires as to fiddle around trying to connect only 4 plus some day you will come across an application that needs all the wires and then you will spend days trying to figure out why it doesn't work.
    The standard for Ethernet over UTP has been layed down. Stick to it and make life easier for everyone.
    Also be aware that RJ45 cat5 plugs and sockets may not be electrically the same as RJ45 plugs and sockets for telephone use. The cat5 standard lays down the inter-pin capacitances and the amount of crosstalk that is allowed between pairs which is different to the needs of telephones. Using sockets designed for phones in place of cat5 sockets will at best give you high error rates and at worst won't work at all.
     
  9. Mathematics!

    Thread Starter Senior Member

    Jul 21, 2008
    1,022
    4
    Ok , got you on all that.
    But
    can I go the other way around like use cat5 jacks for the phone lines ?
    Provide I wire it correctly.


    Also main question on the cat5e jacks they are color coded so you punch the correct color into each slot but they have 2 color codes the top strip is for making 568B and the bottom is for making 568A which color code should I use or does it even matter as long as I do all of them the same????

    Thanks you have been a great help
     
  10. AlexR

    Well-Known Member

    Jan 16, 2008
    735
    54
    Yes, You can use cat5 for phone no problems.
    Straight through connects should be 568A at both ends. You only use 568B at one end if you are making a cross-over cable. You could have other arrangements of colors as long as both ends are the same and you stick to the same grouping of wire pairs. In other word if you exchange the blue wire of the 568A layout with a brown wire then you must exchange blue/white wire with the brown/white.
    On the whole its better and easier to stick to the accepted standard.
     
  11. Mathematics!

    Thread Starter Senior Member

    Jul 21, 2008
    1,022
    4
    OK, got you on that
    Just one more thing to clear up
    If I wire all the cat5 walljacks as 568B instead of 568A would it matter as long as I keep both ends the same.

    I know crossover cable is using 568A on one side and 568B on the other ...
    But what is the difference in using 568B to 568B instead of 568A to 568A on the walljack??? Seems that sites are saying 568B is more common to use. Any way my main concern is when I connect the cat5 cord to the cat5 wall jack... will the cat5 cord be 568A and the walljack be 568B this would be making a crossover by accident???

    Maybe I am missing something but what is the typical cat5 computer cords wired with 568B or 568A. If I knew this then I would just use the same thing as those to do the wall jacks?

    Thanks
     
  12. rjenkins

    AAC Fanatic!

    Nov 6, 2005
    1,015
    69
    As long as both ends of any given cable or link are wired the same and correctly using the pairs in the cable, the A or B standard does not matter. Everything is wired pin-for-pin all the way through.

    The only time you will have problems is if the two ends of a cable are wired differently.
    568B is the commonest standard and it's probably best to stick to that to avoid future confusion.

    The four wire ethernet setup on RJ45 sockets deliberately leaves the two middle contacts unassigned for telephone use (usually the blue/white + white/blue pair).

    You can plug an RJ11 telephone cord directly into an RJ45 ethernet outlet.

    10MBit and 100MBit ethernet only use two pairs, but most newer PCs have Gigabit Ethernet.

    Gigabit RJ45 wiring uses all four pairs, so if you ever want to be able to upgrade to that, make sure you do fully wire all your connectors (and keep the untwisted wires going in to connectors as short as possible, like small fractions of an inch).

    Gigabit devices are usually designed to auto-detect the cable configuration, you do not need crossover cables or special uplink ports on switches, just connect everything with normal cables & make sure all parts are at CAT5 rating or higher.
     
  13. Mathematics!

    Thread Starter Senior Member

    Jul 21, 2008
    1,022
    4
    OK , but I am curious if I wired all the jacks using 568B standards and had a cat5 that was both sideds 568A plugged into the jack to the router/switch will it still work or must you have a cat5 cable that is 586B plugged into the 568B jack?

    In other word the regular cat5 , cat5e ,...etc are they using 568B when you buy them pre-made in stores or 568A.
    Because if I make the jacks 568B and the store bought cords are 568A then will I have a problem?

    Thanks
     
  14. AlexR

    Well-Known Member

    Jan 16, 2008
    735
    54
    As long as both ends are the same and conform to one of the standards it doesn't matter which one you use. The patch cables you buy will work with either standard since they simply connect pin for pin of one socket to the second socket while using the right pair groupings.

    As to which standard you should use, 568A or 568B. The answer is, it all depends where you live!
    See here http://www.ablecables.com.au/568avb.htm
     
Loading...