Anything you choose to do will increase attenuation and potentially shorten the distance you can run PoE.
There is no best practice answer to this as the best practice is to re-run the cable. Since you can't (or aren't willing to do this) then I would do one of two things, although I would still highly recommend running a new cable (you can use the old cable to pull the new cable through walls, etc).
- Use a quality mechanical splice solution maintaining the characteristics of the cable as much as possible (i.e. don't untwist or remove more jacket than needed). This may include the splice box you found or may simply be the use of IDC splice connectors (although these are more of a voice solution).
- Run a 20-30' cable to the break. Terminate one side to a surface mount jack and the other to a male end. This still increases the terminations by two but will eliminate the coupler.
No matter what you choose to do, after you are done make sure you re-certify the cable with a tester to make sure it meets your standard (Cat5E from your post).
When you use TIA/EIA-568B on both sides this is a straight through cable. The colors of the inner jackets don't really matter, much the same as it makes no difference to the operation of the network if you use a network cable with a black or yellow outer jacket.
However, the standard is in place for a real reason, and that is that the cabling system should be implemented in a standard way so that anyone who works on it will intuitively understand what they are working on.
For instance, imagine if someone used your reversed wiring in a real environment, left, and you were now troubleshooting a cabling issue at that site. On inspection, you determine the cable is damaged and it need to be re-terminated on one side and did so with the standard TIA/EIA-568B. After doing so, the cable still will not work.
It isn't because your termination is bad, but because the cable is now a rolled cable. You may waste additional time/resources on trying to re-terminate the cable additional times. Unless you use a cable tester, you may not easily figure out that the cable is now a rolled cabled.
Ultimately, this potentially causes more problems/downtime and isn't really justifiable by any possible reason the original person may have had to not follow the standard.
Old answer (thinking the OP was talking about using TIA/EIA-568B on one side and the reverse on the other):
What you are describing is what is often referred to as a "rolled" or "rollover" cable. Pin 1 connects to pin 8 on the other side, pin 2 to pin 7, etc.
This type of cable would not work for network communications, but is used by many vendors for serial communication, such as console port access.
Best Answer
My guess would be
You can often check the colors by looking carefully at the plug where the wires go to the pins. This will also let you check if the plug was wired to 568A or 568B so you don't inadvertantly make a crossover cable.
However I would advise against doing what you propose to do. Patchcords are made of stranded cable and wallport/patchpanel sockets are designed for solid cable. Using the wrong type of cable for the connector leads to unreliable connections. If you must have a plug on one end and a socket on the other I would suggest making up the whole assembly yourself using solid core cable and make sure that the plug is designed for solid core cable. You can get plugs for both types, again using the wrong type of plug will lead to unreliable terminations. If the vendor won't say what type of cable the plug is for don't buy.