CAt 5e Cable

[WLeg]

Is there any technical reason why one strand of Cat5e cannnot be used to cable a standard telephone line and Computer data at the same time - neither function uses the same pin outs....

Reason: next door neighbour Cat5e'd their whole house several years ago, but now also want to put some additional phones in. DECT does't work too well as they have huge amounts of foil backed insullation in both the walls and ceilings (they built it themselves, and are Danish).

 

[Spinal]

If you want the Cat5E cabling to be CAT5e certifiable (and thus support a gigabit connection) you will be using the full 8 pins.

If not, its a quite common (albeit frowned upon) way to cheaply turn one dataport into two. 2 twisted-pairs (i.e. 4 pins) will carry a signal, albeit not a full gigabit one.

Michele

 

[WLeg]

It's a self done home install, that I've been volunteered (the wife) to help on...so no certification necessary...

 

[Harley Man]

You can use 1 cat5 outlet for both Voice and data, but you may experience errors when the phone is ringing due to the 75Volt ac ringing being induced into the data pairs, but I have been doing this for years in my house as I installed Cat 5 data cabling some years back. I made my own splitters to make it easy to move stuff.

 

[whizzkid11]

You can use 1 cat5 outlet for both Voice and data, but you may experience errors when the phone is ringing due to the 75Volt ac ringing being induced into the data pairs, but I have been doing this for years in my house as I installed Cat 5 data cabling some years back. I made my own splitters to make it easy to move stuff.

I ran Cat 5 throughout the house with a socket in each room connected to a hub in the cupboard under the staircase. Its been working fine for over 5 years, and now has a wireless router feeding the hub - so we have cabled and wireless through the whole house.

 

[ceejay]

Definitely no problem at all, unless as Michele says you want to use gigabit connections. Standard 10/100 connections will be fine. You can even buy splitters which give you one data socket and one or two phone sockets - you use one at each end.

 

[NiallerS320]

Well in today's world of multi gb AVI files, streaming music/videos around the house I'd leave the cat5 as is for gigabit speeds. Digital cordless is the way to go, one in each room, and a couple of spare slots on the base station.

 

[timskemp]

It can be done. Best way to do it is to only wire the middle pair (blue) to the phone line, you can buy a mastering adaptor to convert back to a BT socket. Be careful as some network cards, not just gigabit ones, use the other two pairs as do some network switches - best to cut the blue and brown pairs in the patch lead.

 

[reflexboy]

As us cowboy BT engineers say "any two is a pair"

 

[Spinal]

As us cowboy BT engineers say "any two is a pair"

Thats what I love about standards... there are so many to choose from! Didn't BT and BSI muddle up the pin-out for their sockets a while back, and as such everything is mirrored most of the time? (on a 431 plug that is)

WLeg, as a general rule the blue pair is use for phones - and, should you have an in-house-pbx (or other system that allows the phones to ring independently) you might use the orange/w.white for ringing. The other wire in the pair (white/w.orange) isn't needed - but more often than not is included for consistencies sake.

Hence, you could, in theory, use a 6-2 arrangement if your switches/network cards use an extra pair for some odd reason but you'de lose out a bit on the phone side. A typical INTERNAL phone wiring is:

 Blue with White Bands
 Speech and Ringing
 
 Orange with White Bands
 Ringing
 
 White with Orange Bands
 Not used but usually connected for neatness
 
 White with Blue Bands
 Speech and Ringing

Its always nice to keep things neat - some of the work of (especially the older) BT engineers is amazing! They don't make em like they used to anymore

For troubleshooting, I found this site very helpful! I especially found usefull the advice on using a second master socket when you have only 1 pair of wires...

Michele

 

[fredfloggle]

You can use 1 cat5 outlet for both Voice and data, but you may experience errors when the phone is ringing due to the 75Volt ac ringing being induced into the data pairs, but I have been doing this for years in my house as I installed Cat 5 data cabling some years back. I made my own splitters to make it easy to move stuff.

Experience problems? You might well take out the ethernet port - isolated or not - use the cable for one thing or the other .

 

[fredfloggle]

Thats what I love about standards... there are so many to choose from! Didn't BT and BSI muddle up the pin-out for their sockets a while back, and as such everything is mirrored most of the time? (on a 431 plug that is)

WLeg, as a general rule the blue pair is use for phones - and, should you have an in-house-pbx (or other system that allows the phones to ring independently) you might use the orange/w.white for ringing. The other wire in the pair (white/w.orange) isn't needed - but more often than not is included for consistencies sake.

Hence, you could, in theory, use a 6-2 arrangement if your switches/network cards use an extra pair for some odd reason but you'de lose out a bit on the phone side. A typical INTERNAL phone wiring is:

 Blue with White Bands
 Speech and Ringing
 
 Orange with White Bands
 Ringing
 
 White with Orange Bands
 Not used but usually connected for neatness
 
 White with Blue Bands
 Speech and Ringing

Its always nice to keep things neat - some of the work of (especially the older) BT engineers is amazing! They don't make em like they used to anymore

For troubleshooting, I found this site very helpful! I especially found usefull the advice on using a second master socket when you have only 1 pair of wires...

Michele

Always used to be BOG
Blue Orange Green for the pairs , with the colour being the master of the pair

 

[Spinal]

Always used to be BOG
Blue Orange Green for the pairs , with the colour being the master of the pair

Wow, I NEVER connected the green pair! I always relied on it as a "just-in-case-one-of-the-other-pairs-breaks-in-some-forsaken-place" backup. What are the green pair used for? (i.e. what do they do?)

 

[agatward]

Hehe I wondered when someone would comment.

There are two wiring standards in use on CAT5(e) nowadays, TIA/EIA 568A and 568B. They are essentially the same but two of the pairs are swapped.

http://www.duxcw.com/digest/Howto/network/cable/cable5.htm

Most cable installations and patch cables are now wired to the 568B standard.

Did you know the reason for the blue and orange pairs being used is that the whole design of the RJ-series connectors allows the smaller ones to mate with the bigger ones; so if you were to insert an RJ11 connector (small, used on ADSL modems and american phone lines) into an RJ45 socket (Ethernet), the centre four or six pins would still mate.

Oh and in response to Michele's question - the green pair in the 568B standard is used for T1/E1 and T3/E3 lines, and ATM 155Mbit/s over CAT5 (rather than the usual fibre or coax).

 

[Spinal]

Hehe I wondered when someone would comment.

There are two wiring standards in use on CAT5(e) nowadays, TIA/EIA 568A and 568B. They are essentially the same but two of the pairs are swapped.

http://www.duxcw.com/digest/Howto/network/cable/cable5.htm

Most cable installations and patch cables are now wired to the 568B standard.

Did you know the reason for the blue and orange pairs being used is that the whole design of the RJ-series connectors allows the smaller ones to mate with the bigger ones; so if you were to insert an RJ11 connector (small, used on ADSL modems and american phone lines) into an RJ45 socket (Ethernet), the centre four or six pins would still mate.

Oh and in response to Michele's question - the green pair in the 568B standard is used for T1/E1 and T3/E3 lines, and ATM 155Mbit/s over CAT5 (rather than the usual fibre or coax).

Oh, ok - so the Green pair wouldn't be used in a voice-only/POTS situation, right? If we remain limited by the POTS, you need just 2 wires (possibly 3 for some of the advanced PBX functions) but thats it - right?

I'll admit, when it comes to telephones I'm totally self taught and stumble over my own feet most of the time! Networking is a different matter though

Michele

 

[agatward]

In a domestic POTS installation, the correct way is to use 2 pairs, one wire of which isn't used. Usually the blue and orange pairs would be used:

Wire colour      BT Pin  RJ45 Pin  Purpose
==========================================
White / Blue     2       5         Audio / signalling
White / Orange   3       3         Bell shunt (ringing)
Orange / White   4       4         PABX earth recall (not used)
Blue / White     5       4         Audio / signalling

Colours are listed primary colour first, i.e. White / Blue would mean the white wire with blue bands on it.

Sticking to this standard way of wiring also allows the use of off-the-shelf parts for the outlets, such as these secondary socket adaptors:

http://uk.farnell.com/jsp/Mechanica...UNBRANDED/LJA23/displayProduct.jsp?sku=916341

Note you should normally never have more than one "master" socket on a phone line - the only condition under which this is technically valid is if you lose continuity on the cabling, are only left with one working pair, and cannot replace the cable; a second master socket can then be installed to regenerate the ringing signals.

Unfortunately I have to know about both voice and data as we have some areas in which their paths meet at work, and no I don't mean VoIP We still have one link connected over an ISDX data circuit (not ISDN) at 768Kbit/s.

 

[WLeg]

Useless-ish info I have discovered fixing this up....If you have ADSL on the line, you only need one pair (normally blue & blue/white - 2 & 5) connected....no ADSL and you need the Orange 3 connected...

Now can someone explain this to me ?

 

[agatward]

If I remember correctly It's to do with the way the ADSL microfilters interact with the phone line. The 90V AC (saw wave, if I remember correctly) is shunted in a different way to avoid interfering with the tones used for the data signalling. If it was just handled in the normal way you'd end up dropping your data connection every time the phone rings - this is one of the reasons you should have a microfilter on every socket a telephone is attached to. The other reason is the high-frequency tones do get a bit annoying.