You say that the 100-foot leg is in two 50-foot sections, but you
don't mention how these two sections are connected to each other.  I can
think of three common possibilities:

1.  A female-to-female cable extension connector.  These are not
provided for in the Cat5e spec, but they are certainly available -- at
the risk of adding a certain amount of noise and signal loss.

2. A hub -- another name for a multi-port repeater.  This will
regenerate the power levels of the cable signals, so it's a better
option than the above -- at the cost of delivering power to the midpoint
of the run.
  (The 3-4-5 rule limits how far you can go down this path:  A run may
consist of at most 5 segments joined by 4 hubs/repeaters, of which up to
3 segments may include host devices such as computers.  Each segment may
be up to 100 meters long, so it should be possible to do what you need
to with a single cable -- you just need to find one long enough.)
  Within the 3-4-5 rule -- up to half a kilometer, potentially! -- you
should not have any "timing" or "lag" issues -- network signals travel
pretty close to the speed of light.

3.  A switch.  Switches add some intelligence to try to deliver packets
only to the segments where their intended recipients are connected. 
SOHO gear (LinkSys, D-Link, etc) are store-and-forward, so they DO add a
small amount of latency to the network -- not usually enough to notice. 
The store-and-forward architecture also gets them out from under the
3-4-5 rule, since they are actually re-sending each packet and not just
boosting the signal.

  Cat5e is a type of UTP (Unshielded Twisted Pair) cable.  As such, it
can be subject to interference from other nearby electromagnetic fields
such as from household AC wiring, appliances, and so forth.  Ethernet
typically sees line noise as corruption of data packets, calling for
them to be retransmitted.  THAT can get into big-time "lag" pretty
quickly!
  Make sure that your data cable are not running parallel to power
cables or flourescent lights.  You might consider, if you are looking
for a single 100-foot cable anyway, finding one that is *shielded* --
these generally have visiblr bare metal around the base of the connector
on each end, so the shield layer can make contact with the electrical
ground of the connected devices.  (You can also avoid electrical
interference by switching to fiber-optic cable, but that's probably
overkill....)

  Cat5e cables come in two major varieties:  stranded and solid.  Solid
is what contractors install in building walls, and so it is normally
sold by the box/spool.  It's not at all unusual for people to make their
own jumpers by taking a leftover length of this and crimping their own
connectors onto the ends.
  But solid cables are intended to be static, not moving around much --
it's surprisingly easy to break an individual wire inside the cable.  (I
once handled a call for a malfunctioning network drop where the cable
between the wall and PC was visibly crimped where it had been *under*
one corner of the tower, until it broke.)
  Stranded cables are much more flexible, intended to be moved, coiled,
uncoiled, rerouted, etc.  If you have any choice, this is what you want
between your computer and the wall wiring.
  There's very little difference between Cat5e and Cat6, except that
Cat6 is usually more expensive -- it's tested and approved for
gigabit-over-copper use.  Unless you are actually trying to run gigabit
over this connection, you shouldn't see any improvement that would
justify the price.

David Gillett, CISSP CCNP


3. 

-------- Original Message --------
Subject: [PCBUILD] Network lag on Cat 5e
From: Brad Feuerhelm <[log in to unmask]>
Date: Tue, August 16, 2011 11:18 am
To: [log in to unmask]

Hi again

Another question on another topic.

For the network experts out their. I have a wired leg off a wireless 
router running Cat 5e cable. I seem to have a lag on a section which is 
100 foot long but it's in two 50 foot sections. I'm wondering as to the 
possible chance the lag is caused by the 100 foot length as being to 
long and thus a signal loss? I don't know for sure how long is too long 
on Cat 5e. Also if it is the length, would putting a switch in the 
middle help or make things worse. The lag might also be caused by the 
computer using the on-board LAN (on the motherboard). I do have a 3-com 
(pci) card I can install if using the on-board LAN might be the problem.

Thanks

Brad Feuerhelm

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