PoE over older cables

[Anothername]

Hi all,

 

Were looking at updating our wireless network and having some new network points put in for some PoE WAP's. In some of the area's we are going to need new cabling/data points, but in a few area's we have existing Cat5 with data points already in place. Would you suggest running new cabling to replace the old or can we run PoE over the Cat5 that we have existing? Were currently looking at the Unifi system. Thanks.

[synaesthesia]

No reason why not, but it would be wise to give those cables a once-over with a decent cable tester.

[PotNoodleTech]

Best practice to run new cables if possible for WAPS as the shielding comes in handy with POE devices, particularly if using higher end APs that use 20+ watts.

 

That being said I do still have a couple of Waps on older unshielded cat5e and don't appear to have any issues.

[NDEJosh]

Admittedly a little bit of a resurrection - I apologise.

 

However, you should be fine providing the cabling was installed to a high quality.

 

I'm assuming the cabling is Category 5e and not just Cat5.

 

Providing that all pairs are punched down correctly at both ends and the cable is a good quality cable (not CCA, Copper-Clad Alliminium) you will be fine.

 

 

As AButters mentioned, shielding does come in useful when PoE applications are considered, however, this is more beneficial at larger demands (take a look at 802.3bt for example) or when cables are bundled together in a comms room for example.

 

 

I have witnessed in the past that the brown pair (the pair used for conventional 802.3af/at PoE) isn't punched down. This pre-dates Gigabit days where not as many pairs were required.

 

 

 

Simply put, bad installers or bad cable will provide you with issues.

 

 

However, good installers and a good cable will mean you have no issues.

 

 

A TDR/Modtap would allow you to double check all pairs are punched down, but only the most expensive cable testers will ensure the cable can handle the PoE safely.