Speed of my internet connection

Question

When I plug in my computer to the "World wide web" with an Ethernet cable, does its length affects my internet speed?

Answer 1

No. The length of the ethernet cable does not effect your connection speed. Transfer rate of the ethernet protocol runs at a fixed speed (e.g.; 100 MBPS) regardless of your cable length. Your ethernet cable must be able to transfer the signals in this particular speed. If it can't, the connection cannot be established in the first place. If your cable is too long, it won't be able to preserve the wave form of the signals because of a physical phenomenon called "Channel Dispersion", and the connection will fail.

But I have to mention that, there is a critical cable length interval (a transition length between the safe and unsafe legths), in which the connection will still be established, but there will be transfer errors. Because of this, the connection speed will reduce. As you push the limits, the error rate will increase, and overall connection speed will drop down.

Answer 2

The length of the cable may affect the speed you get as a reduced signal creates more errors and requires the protocol to go through more retransmissions of corrupted packets. However, lengths of (say) 10m between modem and PC will have no noticeable affect. This is assuming you do not have a gigabit Net connection (mine is 100Mb/s and works fine over 20m of CAT6 cable)

Answer 3

Length of the cable will not affect the transfer rate. However, it will affect the latency and it can affect the signal integrity.

Signals propagating down an electrical cable generally travel at around 70% the speed of light. This results in a delay of about 1.5 ns per foot. 670 feet of cable would add one microsecond (one millionth of one second) of delay. Over very long distances, this can be very noticeable as 'lag.' Generally delays from cable length are only really noticeable when your traffic is routed through something like an intercontinental fiber optic cable.

Electrical signals travelling down a cable slowly leak away the farther they go. Electrical cables can have loss on the order of perhaps a few tenths of a dB per meter. Let's call it 0.2 dB per meter. 100 meters of cable would reduce the signal by 20 dB, which is a factor of 100 - 1% of the original signal comes out the other end. Digital circuitry is great in that it can tolerate some amount of loss. However, beyond a certain point, it is not possible to communicate without regenerating the signal. As a result, there are limits on the length of cables for reliable communication based on the type of cable and the data rate required.