Ethernet Alien Crosstalk & Cat5e vs Cat6

[northtexas55693]

First point:

Got this link from another TH user in another thread I started the other day:
Automatedhome.co.uk - Installation Pitfalls of Cat6 cabling
Quote:But once we get to the 250 Mhz limit for Cat 6 the wire is acting just like a wave-guide. Most of the electrical energy travels from one end to the other outside the conductor as electromagnetic energy. Quite a lot of it travels within the plastic of the insulation, so these are no longer just mechanical devices for protecting and holding the wires together, they are now an integral part of the dielectric of the cable. The sheath becomes a significant factor in the cable’s impedance make-up.

If you run multiple S/UTP through a conduit (say 4 cables in a single vertical 1" conduit in wall) would there be crosstalk between the cables? Same question with running multiple cables alongside each other in an attic? I see hundreds of cables laying on top of each other in basket systems so I think I am over analyzing but wanted to ask anyways.

CablingInstall.com - Effects of alien crosstalk on the physical layer
15 year old article but brings up super detailed information about alien crosstalk. Given the newness of Cat6 at that time and their test conditions are their findings still valid?


Second point:

Audioholics.com - Why Your Cat6/5e Network Cable is Slowing You Down: Interview with Blue Jeans Cable
Cat5e is much more forgiving both with price and termination/cable running than Cat6 (seems to be the "accepted" notion)

I WAS planning on running Cat6 mostly for higher bandwidth which allows for more future proofing.

Now I keep finding articles like this that say that unless you really need it now or are running large scale networks (I am going to install what I think is a simple home network; 24 runs @ 100-150 ft, 6 PoE cameras, 18 keystone jacks for PC's, routers, TV's, audio, game consoles. NAS, printer)

I don't have test equipment and probably wont rent any or hire anyone to test whatever I install so I will effectively be relying on my own research and manufacturer specs (scary thought I know, but I am planning on running Belden wire which is supposedly good stuff, and careful handling during installation)

If Cat5e can get me by for those above needs for the next 5-10 years I will run it now.
If Cat6 would be overkill for my needs, cost more, and may/may not perform to spec I would rather skip it.

 

[bill001g]

We have huge bundles of cable ziptied together in server cabinets and lots of power cords running very close and many times actually touching the ethernet at places. When you put 30 1u high servers in a rack all with dual power and at least 3 ethernet ports each you get massive amounts of cables. Then you have multiple racks next to each other.

In most cases this is a mixture of cat5e and cat6...whatever was available at the time.

The switches that control these servers are connected to every monitoring tool there is...mostly for utilization rates. Even on ones that have been installed for many years the error counts on the ports are zero.

You really have to look at who is writing these article. Most the ones screaming about this are companies trying to sell you cable. A lot of there stats are there to confuse. They love to spout amount how many mhz the cable can run. It doesn't matter as long as it is more than the port requires it will work. A 1g port only runs at 1g even you run it on cat7 cable. Now sure if there was 2g or 5g ports maybe it would have a use.

Cat6 cable main purpose was to allow you to run 1g on 2 pair of wires like 10m and 100m did. When the industry decided they would use 4 pair cat6 became a product that had no purpose. Only a tiny number of cisco interfaces were produced that could run 1g on 2 wire standard. Because of this the cable manufactures ramped up the hype machine and do there very best to get people to buy into bigger numbers are always better.

That said you can actually get cat6 cable cheaper than cat5e at times. Why exactly is supply and demand thing. So if you can get it cheaper you might as well use cat6.

If you are looking to "future proof" go to cat6a but use cat5e or cat6 jacks. This will let you go to 10g if we ever see end user devices that can actually use more than 1g.

 

[northtexas55693]

I can agree there is a lot of hype surrounding the search results when I look up "home networking"

From what I can tell "home networks" are still an emerging niche market. People like myself who are building a new home at least think about it, and if they have any sort of tech bug like myself, really look into it and probably install one. Existing homes usually only get one if the owner is really into tech.

The second article I posted seemed as legit as an online article can get without being a peer reviewed research paper. Super dense material and something that should be considered in high throughput enterprise systems, though home networks don't fall into this category IMO. I only cited it since it was packed full of information which I thought would be of import.

In the end, since I am running 1" conduit for in-wall and open air in attic, running new lines 10-15-25 years from now should not be a problem.

I guess a follow-up question/concern would be this:

Given that I wont be testing the network after install; I am concerned that running Cat6 "improperly" IE too much line bend, terminations not good enough, etc. would affect the network speed so much that it would perform at a lower level than a Cat5e network which is supposedly so simple to install "right" that a child could do it.

Is this concern something worth thinking about?

 

[bill001g]

You have to read between the lines. They are assuming you are going to use the cat6 cable to run more than 1g. The frequencies the signaling runs at is controlled by the port. It send the data at the exact same rate if you have cat5e or cat6. So IF you had some device that could send at the higher signaling rates then you need to worry about things like this.

Cat6 cable does not have any other install requirements than cat5e cable if you only plan to use it for 1g.

It is only when you run 10g you need to worry about stuff like this and the solution for that is to go to cat6a cable which is more resistant to those kinds of issues than normal cat6.

The more I see this the more I think it is people desperate to sell cat6.

If you can get the cat5e cable for cheap I would just do that. Since you are running conduit in the walls it running open in the attic you can easily just pull it back out and run cat6a or cat?? whatever in the future.

 

[northtexas55693]

1000 ft Cat6a S/UTP - $287
1000 ft Cat6 S/UTP - $107
1000 ft Cat5e S/UTP - $81

Haven't even dug into switch pricing yet. Just know I need at least 6 ports that have PoE for security cameras. I was thinking it might be more economical to get a dedicated switch for PoE devices, and a smaller switch ~16 ports for the networked devices. I presume the more ports the higher cost, throw in PoE capabilities and it goes up higher from there. This is all for another thread and another time I guess.

Any issues for compatibility/network setup by running 2 switches?

 

[bill001g]

Switches will be transparent. The limitation will be the cable connecting them. The group of machine on one switch would have to share the capacity when they talk to the group on the other switch. Traffic within each switch would not be impacted. This is why you see switches with higher uplink ports. Used to be you would see 20 ports at 10/100 and 4 ports at 1g. Now the uplink ports are 10g or 40g. It all is going to depend on your traffic pattern but I suspect 1 1g connection will be more than good enough.

With PoE what you will find is that all ports can not be powered at the same time. You are going to have to dig though all the fine print and see what the power budgets are. A 24 port switch that only has enough power to run 8 ports at full watts is going to be cheaper than one that can run all 24 ports.

Be very sure your cameras are 802.3af when they say PoE. It is very common for cameras and even some AP vendors to call 12 volt systems PoE and then you must use their custom power injectors.

 

[crashnburn]

I need to take some notes on these as well and test CAT6 Cabling.