Question How to test the transfer speed of Ethernet cables without a tester?

[d239919]

Dear Community,

I would like to ask whether it is possible to test the transfer speed of Ethernet cables without using a proper tester. Would it be possible to send packets between two devices or between a node and a router, and based on this determine the transfer speed? The reason why I am asking is because I crimped my own Ethernet cable and I would like to find out whether I have done it properly. Thank you in advance.

 

[DeauteratedDog]

Check out iperf - it does just that. It needs two machines, tests throughput between them.

iPerf - The TCP, UDP and SCTP network bandwidth measurement tool

iPerf3 binaries - measuring TCP, UDP and SCTP bandwidth performance

iperf.fr

 

[SAINT.LUPIN]

Connect a computer at the cable you want to test and run a speedtest or transfer files trough FTP between the two devices. If you need to be acurate run iperf on both computers and get a proper measurement.

 

[d239919]

Thank you for your replies. I came across iperf, however, I did not manage to get it working. I connected both devices to my router. I set one of the devices as a server to receive packets (dir/iperf3.exe -s) and the other one to send packets (dir/iperf3.exe -c server's IP address), but it could not establish connection. I was able to ping the "server" node, but not able to make connection using iperf and both of those devices had internet connection, so the cables are working fine. Maybe I forgot to put in some parameters which is causing the problem. I tried connecting those devices directly, but I do not think that would work as my wires are aligned for crossover connection. But would it be possible to ping another device if I were to connect them directly using a straight through Ethernet cable? And what would be the IP address if it were not to be connected to a router with DHCP which assigns IP addresses?

 

[bill001g]

Iperf is pretty simplistic to use so I would keep trying. If ping work iperf should work. If you do not have a router in between you must manually assign ip addresses.

I think you can skip the -c on the client side not sure realized I did not have iperf loaded on any of my machines.

You should not use any form of crossover cable. The concept does not really exist for gigabit cables. It actually transmit and receives on all 4 pair in both directions at the same time. I have not seen a 100mbps port in a pc in a very long time and the ones that are in router have a feature called MDX that allows you to use straight cables. It will in effect make the cable into a crossover cable with software.

What would be really nice is if you could see the number of packet errors your got on ethernet cables. Many commercial switches have this feature. Then again I used to see reports on many thousands of ports and the numbers were many times zero. The errors mostly occur when a user unplugged his machine from the port. A non defective cable will most times have zero errors.

Pretty much a ethernet cable transfers at full speed all the time. The only way you get less transfer is if the packets are damaged and are discarded. Very technically even the bad data is transferred at full speed.

IPERF tends to be the best tool because it is not affected by things like disk speed or file structure. You should see over 900mbps in both directions.

 

[d239919]

I followed this guide

View: https://www.youtube.com/watch?v=Hx2cJAh28oY
and I made sure that I turned off VPN and anything else which could be blocking the connection. I am running it through a router which assigns IP addresses using DHCP. When I try to send packets across, it states that it could not connect to the server. No idea why it is doing that for me, whereas everyone else is making it work.

 

[DeauteratedDog]

Maybe a firewall problem? Try turning off the firewall on the server (and maybe the client too - can't hurt).

 

[d239919]

Maybe a firewall problem? Try turning off the firewall on the server (and maybe the client too - can't hurt).

I tried turning off the firewall for both of my devices and it did not seem to help. It is annoying. I can not figure out why I am not able to establish connection with the "server", but I am able to ping it.

 

[bill001g]

Try going the other direction. Run the server on the machine you are attempting to run the client on. You can make the data go both ways from either end.

 

[d239919]

Try going the other direction. Run the server on the machine you are attempting to run the client on. You can make the data go both ways from either end.

I tried using different devices and I still could not manage to establish a connection. It waits for a while and then it just says that the connection timed out. I think it transfers all the packets successfully, but it is just the confirmation which does not get back. I do not know, maybe there is something in the router's settings which needs to be changed. Anyway, if you go to the adapter's settings and click on view status of connection, it will show up all the information for selected network card such as speed and signal strength etc.