[TowerTalk] Data transfer

[K8RI]

On 7/10/2013 6:53 PM, James Wolf wrote:
> A couple things here.
>
> If your wired network is using a cable that is anything over 100 meters, you
> are at the extent of what you can run.  The reason is that for each pair of
> conductors in a CAT-5/6 cable the twist is different, and the next frame
> will start to overlap signals on the first frame.

I might phrase it a bit differently in that at gigabit speeds the 
packets take so little time you create your own collisions and one 
collision creates others
  You can however extend
> the length by using a switch.  In using a 1 GB wired link, it is critical
> that there are no sharp bends,

Cat 6 kinks easily so it pays to use sweeps and when pulling, never let 
the cable coil up where it goes into the conduit as its a sure fire rout 
to a kink and although it's not a short, the data will treat it as if it 
  were.

I've been running parallel, 130 ft runs of CAT6 with a gigabit network 
with no problems and there are 9, 90 degree bends in each run.

  cables don't cross or are not rolled up.
> Early on using standard CAT5 you were lucky if you could get a 1 GB steady
> rate at 20 ft.  Newer cables, CAT5e and Cat6 are much better.

CAT6 uses dividers so each pair is held separate from the others.

   Best bet is
> CAT7 which has shielding around each pair of conductors and tolerances are
> very tight, but you have to be careful that your connectors match your
> equipment.  I'm a few years dated on this information so someone might be
> able to shed some light on current practice.
>
> Have you looked into the new wireless standard, 802.11ac?

I have it on my newest router, but it's still slow.

   It is just
> starting to hit the market and I know of no one who has used it yet, but I
> hear that it is in the new Mac computers.  You can go to exotic measures
> with it and get over 1 GB aggregate rates.

I have not been able to get a gigabit with it yet and I'd have to use a 
repeater to reach the shop which has bonded metal walls and ceiling. 
It's only a little over a 100 feet from the router.

73

Roger (K8RI)


   I think it can use up to 160 MHz
> of bandwidth in the 5 GHz band.
>
> Jim, KR9U
>
> ________________
>
>> On 7/8/2013 6:50 PM, K8RI wrote:
>>
>>> I can't get rid of the wired network. wireless isn't fast enough for
>>> large file transfers and I do a lot of photography with typically 8 to
>>> 10 terabytes on each of 4 computers.  Unfortunately even a gigabit
>>> network is slow when talking this much data.  OTOH  I've reached the
>>> point where the computers I/O is now the limiting factor.
>>
>> Go optical fiber.
>>
>> -Steve K8LX
>
> Steve,
>
> Can you offer suggestions as to how to make fiber practical for a DIYer? I
> would love to run fiber from my barn to the house, a run of about 100
> meters in buried ENT.
>
> Bulk FO direct-bury cable, connectors and media converters are sort of
> affordable, especially given the advantages over copper.
>
> The problem seems to be fitting the connectors to the cable. I have not
> found a source for pre-assembled direct bury cable, and I am not certain
> that I would be able to pull it through the conduit anyway. Tool kits for
> the purpose are way out of reach, and I have not found a rental source. I
> do know a couple of folks with training and tools, but they're not
> interested in just applying the connectors, and will not help me pull
> cable that I sourced. Paying one of these guys for the entire installation
> is just plain not affordable.
>
> --
> Art Greenberg
> WA2LLN
> art at artg.tv
>
> *********
>
> _______________________________________________
>
>
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk at contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
>