Discussion between me and an IT tech 1

[classydreams]

I do not do a lot of network cabling, can someone answer this question. An IT guy insisted that I must use all four pairs on every network connection but I understand that only 2 pairs are actually used 12,36. Usually Orange/White / Green/White. I have tired this and it does work I have heard that this is for 10/100 but on a Gigabit network yes all four pairs are used. Can someone clear this up for me? Thanks

 

[TouchToneTommy]

There are situations where all 4 pairs are needed, so don't be lazy and sloppy and neglect to punch down all 4 pairs, or worse yet, try and split out 2 ethernet connections on a single cable.

 

[meyer1y2k]

I am one of those that likes to know why things need to be done rather than just be told "because this is how you do it"...

Yes - the orange and green pairs are the transmit/receive pairs on the standard Ethernet connection but there are now standards in place that use the other pairs.

As you pointed out, the 1000BASE-T standard uses all 4 pairs.

You might also be more likely to have devices that use POE (Power Over Ethernet). This will also use the other pairs.

Save yourself a lot of potential future re-work and terminate all 4 pairs.

Please understand we are not trying to beat up on you but to save you the pain some of us might have already borne trying to save a little labor. ~ Mike

 

[delladiaz]

let me throw something out to you guys. There are situations where because of the design of a building or lack of facilities or because of the cost involved in pulling additional or new cabling there is no other option other than splitting the cable. Or if you only have 2 pairs to work with or the others are damaged. What have you done in those situations. Especially with older buildings that were never designed for technology. Sometimes you just have to make what you have work. Some situations do not require the highest speed for example if someone is just checking email. What are your comments please and experience. Thank you

 

[classydreams]

Than you for your replies.

Yes I agree with meyer1y2k I always like to know why something is the way it is. This is important for the educational value and if another person asks me why.

I would like to know about the question about what do do when the is a shortage of facilities. Also one more issue, is there any disadvantage to adding a switch at the end of a run to add more network connections without having to run more home runs. I know this does add multiple points of failure like bad switches, failing power supplies. I see this done all the time and wonder if this is just the cheap and fast way to add more connections.

 

[mforrence]

IF we are forced to split cable pairs, we don't actually modify the building wiring. Instead, we use an external splitting mechanism on each end - either one manufactured for this purpose or one that we make up. Advantage is that, by removing this external splitter, we have "undone" the change, and building wire is left untouched.

 

[edfair]

So far as using switches to multiply connections, yes, in those places where failure of the switch doesn't affect critical services. Even to the point of having 3 switches in my home network.

Although I advocate punching down all pairs I have used just 2 in one location where one wire opened in the original pull. I would do anything short of going wireless as replacement for that one cable. Replacing it would be a 4 hour job opening conduit above the ceiling of a working office.



Ed Fair
Give the wrong symptoms, get the wrong solutions.

 

[meyer1y2k]

This has become a very interesting topic and, yes, sometimes the industry standard cannot be accomplished due to other factors. I was basing my answer on the assumption doing the job to standard could be easily done and I have seen some cases where the minimum to "just get it working" was done when there was no reason for this.

There are some pretty cheap solutions to extend Ethernet over 1 pair or even over different physical mediums. I had a site that just needed one PC in an adjoining building and wireless would not work due to the buildings construction. There was perfectly good CAT 3 between the building already. For about $200 the customer purchased an Ethernet extender from Amazon that would extend Ethernet over CAT 3 to something like 1000'. This was much cheaper than pulling a CAT5 UG cable. I installed, it came right up, and we scored about 50Mb on a bandwidth test. In this case, it would be more than what the user needed for web browsing, printing, etc. I would not recommend this for something bandwidth intensive but for 1 or 2 users it is fine.

Switch to switch will work too if you have to do it. Just remember though, that all the users on that switch will have to share the bandwidth available on the 1 port back to the data closet. For the average user, they are not going to notice, but you might see some performance problems where multiple users need high data throughput.

One thing I have come to appreciate in this industry is that there is rarely 1 right answer. Some answers are better than others but we seem to always find our way. ~ Mike

 

[classydreams]

Yes thanks for your answers. Some customers just will not spend an extra penny. When I have told them the right way to do it and then don;t hear from them the next time I am there I have seen a hold hammered through the wall and a network cable dragged across the floor, taped down under chair mats and to the computer and THIS was all done by their "computer expert"! This guy went behind my back for a few bucks and told the customer he would do it cheaper. This is a multiple million dollar printing company. I was shocked!

 

[SYQUEST]

With clients that do that kind of work, guess who is liable if something goes wrong? The insurance company will have a field day! Or even OSHA, if a person is injured. That is why we have building and electrical codes. Some companies don't care! Then they get sued or fined! Or when it stops working and they call you out to fix it...

I have told clients there is one way, the right way, and do it right the first time! Otherwise I pass on it. There are a lot of stupid IT people out there, that have no business doing this stuff...

Just my three cents...

....JIM....

 

[delladiaz]

I agree. I am really glad about the cloud because it's been rapidly getting rid of my customers servers and expensive IT quipment in the phone room and what I've noticed is the reduction or elimination of the incompetent IT geek. All these guys need is a business license for $45 in this state they can hang a shingle out and say their IT experts. I'll be glad when the majority of them are gone and out of the phone room. They've been nothing but a problem since they started messing around with telephone systems and inside low voltage wiring. Most of them are unprofessional and usually rip off the customer because they don't really know what they're doing. A lot of them I've been trying to make extra money by installing crappy VoIP systems and getting rid of their telephone systems. Have you experienced any of that? Of course they think you just plug the handset in to the back of the computer and everything works but it always provides horrible service for the customer.

 

[meyer1y2k]

I get glared at but I tell IT weenies that if there is anything wrong with your network, VoIP will point it out to you. Every time I get a this VoIP is crap call I go to site and find a bad patch cable, frayed data cable, etc. It amazes me how many calls poor infrastructure generates. If I am allowed to clean it up, I rarely have to visit the site again.

My favorite is the network completely down because someone looped the switch which does not do spanning tree and the cables are an awful mess.

Forgive my cynicism but I heartily agree there are many less than competent IT people. It makes me truly appreciate the good ones.

 

[jknichols]

While I will agree that there are time when it is expedient to split a cable or run a long patch cable around/over a wall on a TEMPORARY basis, there is no excuse for getting lazy and not connecting all 4 pairs on the initial install. Likewise, if you know you are pulling a cable on a difficult run, get another box or two of cable and pull extra cable at the same time - the repeat labor later will far outweigh the initial wire cost.

Unfortunately, around here, "Temporary" still has a half-life of about 6 months to a year. While I would never hammer a hole thru a wall, I might if necessary drill a small neat hole.