[SOLVED] Can a PoE ethernet repeater offset RF interference?

Oct 2, 2020
3
0
10
0
I have CAT6e cable running from the main living room where my Nighthawk C7800 modem/router is located. I have gigabit service and when a wired device is directly connected to it, I get gigabit speeds. My main PC is in my office on the end of the house, so CAT6e is run from an outlet, up the wall, into the attic and running to my office via an outlet where my PC is connected to it.

My PC only gets like 440-460 mbps. The total length of my CAT6 is only 29 meters, so I'm not running into length issues. My NIC is configured for gigabit. I didn't install the CAT6 and I can't really find where the cable is in the attic, but I suspect major RF interference as the outlets are next to power outlets, so I assume the CAT6 is running next to power lines within the walls and attic.

So, how can I work around this without having it all replaced? Will a PoE repeater (put into my office) able to "reboost" the signal and get me up to higher speeds?
 
Well, run a cpature and see what it shows you. You will see errors and retransmits at any data rate if the cable is bad. Ideally, put computers on both ends of the cable and run iperf in each direction with large frames, that will tell you the truth right away.
P.S. CAT 5e is just fine at the speeds you have anyway. CAT6 is needed for over 100MHz (for copper-wired ethernet it would be 10GBps)
 
Last edited:
Reactions: bill001g
Oct 2, 2020
3
0
10
0
Even cat6 loses a fair bit (~5dB/100ft) - https://media.extron.com/public/download/files/specs/UTP_CAT_6_cable_020402.pdf

What speed do you get at the router?

PoE is about the same loss as ethernet cable from my experience. I use it to save punching holes in walls and then the missus punching me in the head.
Do you think 29 meters (90-something feet) would cause me to lose half of my speed? Directly connected to the modem/router I get around 940 mbps.

I'm not sure what you're saying about the repeater though. I would assume the repeater will boost the signal from the point I connect it, yes?
 
I have CAT6e cable running from the main living room where my Nighthawk C7800 modem/router is located. I have gigabit service and when a wired device is directly connected to it, I get gigabit speeds. My main PC is in my office on the end of the house, so CAT6e is run from an outlet, up the wall, into the attic and running to my office via an outlet where my PC is connected to it.
Did you get those speeds by connecting your PC through the router or directly to the ISP (while the router is in the "bridge mode")? The router part might be the bottleneck, and not necessarily by bps, but by packets per second.
My NIC is configured for gigabit. I didn't install the CAT6 and I can't really find where the cable is in the attic, but I suspect major RF interference as the outlets are next to power outlets, so I assume the CAT6 is running next to power lines within the walls and attic.
I would expect for that CAT6 to be shielded. Are the devices synced at 1Gbps? Try to make a Wireshark capture and see if there are a lot of retransmits. In that case, it might be the cable or the port, or the wall socket.
Will a PoE repeater (put into my office) able to "reboost" the signal and get me up to higher speeds?
I doubt it. PoE has nothing to do with it.
 
Oct 2, 2020
3
0
10
0
Did you get those speeds by connecting your PC through the router or directly to the ISP (while the router is in the "bridge mode")? The router part might be the bottleneck.

I would expect for that CAT6 to be shielded. Are the devices synced at 1Gbps? Try to make a Wireshark capture and see if there are a lot of retransmits. In that case, it might be the cable or the port, or the wall socket.

I doubt it. PoE has nothing to do with it.
No, I just connected it via a CAT6 cable into port 1 of the router. No outlet or any of that jazz.

I actually tried to install wireshark and my PC crashed during the install and I'm having issues getting it to re-install, much to my frustration.
 
Well, run a cpature and see what it shows you. You will see errors and retransmits at any data rate if the cable is bad. Ideally, put computers on both ends of the cable and run iperf in each direction with large frames, that will tell you the truth right away.
P.S. CAT 5e is just fine at the speeds you have anyway. CAT6 is needed for over 100MHz (for copper-wired ethernet it would be 10GBps)
 
Last edited:
Reactions: bill001g

ASK THE COMMUNITY