If cable is going in the attic, using LC PLENUM grade as the materials handle higher sustained temps better and is the “ultimate”. This cable for higher temps is called LC, or Limited Combustible, that is all TEFLON 200C. LC cables have the LOWEST smoke emissions available. OK, but the CHOICES are more limited for LC and isn’t the best compromise in my mind. But to ward off the overkill crowd I do need to mention LC grade cables.
Standard CMP Plenum cable is modified LS-PVC 90C jacket and FEP insulated singles. Smoke emissions are low, but not as low as LC rated designs. LC cable is expensive! The 3612/13 carries a good 90C temp rated cable design, and 0.6A POE rating, and is 1 GbaseT.
For the price and to the minimum standard CMR 3612 riser rated will work in the attic. Get the HIGHEST temperature rated cable you can, as this indicates a better higher temp PVC jacket is used, too. The POE, Power Over Ethernet, standard requires a worst case HEAT soak to be passed, thus good quality jackets need to be used that retain what is called Tensile and Elongation, or T&E, properties compared to virgin materals. Look for 75C or above rated cables.
You can design for higher sustained POE power in two ways, or use both ways;
- higher temp material to handle the higher heat from smaller wires.
- larger copper to lower the heat. You can use lower temp 60C jackets with larger copper, for instance, with big enough copper.
Bigger copper means bigger cable, though. So a more balanced material and copper approach is needed. And don’t forget, we are ALSO sizing copper for Ethernet signal attenuation, not just POE losses, too! Watch both hands at the same time.
There is a LIMIT to using higher temp material, though, and the smallest copper you can. The LOSS across the cable can’t exceed set loss limits (too little power to run devices at the end!). So once you reach that current squared time resistance limit, you need larger copper to go to a higher standard POE current rating. The jacket’s temp rating can’t help you with copper losses, just T&E retention! Both are in play at the same time.
POE is pretty involved to balance with all the other requiremments. 3612/13 CAT6 is the best balance of cost for Ethernet and POE, both.
On WHAT cable to use, I suggest for 1GBaseT to use 3600 series CAT6 as it also uses a larger copper wire for POE, 23 AWG not 24 AWG, so it can run powered ethernet devices better. Not so much for the Ethernet, that 5e can run. 5e can’t handle DC powered devices as well before the loss limits are reached.
The next step is 10Gig. This is really confusing to many people. This kind of cable has to meet cable to cable interference as well as internal pair to pair cross talk, both. This noise mitigation allows shannon’s law to extend the bandwidth to 10G.
There are indeed 1000baseT, or 1GbaseT, cable that specs HIGHER on internal specs than 10G like DT600e and 4800 series or cables like that. BUT, they DO NOT mitigate cable to cable noise and thus may not meet 10G worst case distance (100 meters) performance. So don’t ignore the importnce of cable to cable noise.
There is a downside to 10G, and not a bad downside at all. Using the PAM encoding technology developed for 10G, you can sort of alter the voltage states to create 2.5G and 5G links as well with lesser cost cable. We see those ports on new PC’s now.
Again, make sure you get cable that meets the cumulative noise issues of each speed rating both internal (can be canceled) and external (can’t be canceled).
Sorry for all the info, but this art is not as simple as I read people believing here and elsewhere. It isn’t as easy as four 24 AWG twisted pairs is Ethernet. The tech is incredible.