What is a booted cable?
A "booted" patch cable is a cable that has a molded plastic boot that is either integral to the connector, or
“slips”
on the RJ45 connector and a portion of the cable itself. Sometimes a booted cable is also referred to as a
"strain-relief" cable, which is exactly the purpose of the boot…
There are two main types of boots that you will encounter, a separate boot that you can purchase to put on a
cable
that you’re making on your own, or when you buy a manufactured cable that has an injection-molded boot.
The injection-molded type is more efficient than slip-on boots as the injection molding process pushes the
material
right into the connector and around the individual wires. As you can imagine the main reason for the boot is
to
protect the cable and the connector from being damaged, wires being dislodged from the connector body, etc.
Booted patch cables are a better choice for applications where the cable will be connected and disconnected
frequently, lasting much longer than their non-booted counterparts.
So what is a “snagless” boot
When an Ethernet cable is referred to as “snagless” it is referring to an extra part of the boot that covers
the end
of the locking tab. There are two common types of protectors you will encounter; Bubble and Ferrari.
The main difference between the two styles is that bubble tab protectors are harder to disengage than Ferrari
tab
protectors. Some people hate bubble boots because they can be frustrating when disconnecting the cable,
others love
them for the same reason. Ferrari boots are a good choice for high-density applications as they are much
easier to
disconnect when space is limited.
The locking tab of an RJ-45 connector is easily damaged or broken off, one of the most common ways to do so
is when
pulling a cable through a bunch of other cables. If there is no protection for the tab then the tab will
become
stuck (or snagged) on another cable and break off, rendering the cable useless.
What is a non-booted (crimped or assembly style) cable?
Technically every network cable starts its life as a non-booted cable. The outer jacket of the cable is
stripped to
the required length, the internal wires cut to the right length, put in the right order, and the connector
placed on
the end of the prepared cable. Once the connector is in position, it is fixed on the end by "crimping" the
gold
connectors onto the wires and also pushing a plastic bar inside the connector onto the cable jacket that is
inside
the connector for stability.
When you use this type of cable there are some advantages and disadvantages. As you can imagine the
non-booted type
is slightly less expensive than its booted counterpart, but the actual difference in price is minimal,
sometimes
only a couple of pennies depending on where you buy them from.
The non-booted type has no strain relief capabilities or protection for the locking tab on the connector. But
there
is one advantage to non-booted cables… They are very suited to high-density applications such as patch
panels. If
you have a 96 port patch panel with 96 patch cables connected to it, things are going to be a bit tight! If
you are
using molded booted patch cables you may run into a couple of issues…
The point at which a crimped cable is flexible is right at the point the cable exits the connector, this is
not the
case with a booted cable, you have the additional distance the boot takes up before it becomes flexible.
This may
not sound too bad, but this can make a big difference in a couple of ways. The cable will protrude further
from the
patch panel, due to the boot, which may make it difficult to fit into existing cable management, or could
even mean
that the door to the rack will not close. Additionally, the locking tab may be difficult to disengage on a
booted
cable in our patch panel scenario, the extra room the boot takes up can make a difference between being able
to
press it in enough to release the connector or not.
A word on choosing the length of a patch cord.
We are mentioning this point in this article because the differences we have just described between booted
and
crimped play part in choosing the correct length of patch cable for your application. Anyone who is building
a rack
in an office or multiple racks in a data center wants to make a good job of cable management.
Untidy cables are painful to look at and are also a reflection on the installer themselves. We have seen
installers
meticulously measuring distances between patch panels and equipment with just plain cable, string, etc. to
work out
exactly what lengths to order, but this approach usually ends badly.
The length of a patch cable is measured from the end of one connector to the end of the other connector, not
the
length of the cable without the connectors. So why mention this in an article about booted vs. crimped
cables? Well
as described above, a booted cable does not flex as soon as the cable emerges from the connector because of
the
boot, the length of the boot is obviously part of the overall length of the cable itself.
So getting back to our installer who has just worked out he needs 300 3ft booted patch cables. When he comes
to
install them he suddenly finds out that hardly any of his patch cables are long enough!
So where did he go wrong? When a patch cable is booted, the cable does not bend directly at the connector
body like a
non-booted cable. There is the length of the boot to account for on both ends of the cable, this can reduce
the
overall length available between the ports he is trying to connect.
The best way to work out the needed length is simply measured as described and add 6 to 12 inches to your
measurement. It will not matter that the cables will work out longer in some instances, as long as you order
the
same lengths it will be easy to produce a tidy and symmetrical result.