200 mbps but only getting 90 mbps cabling issue?

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samgdan

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#270070 21-Apr-2020 21:49

Hi all,

finally I have the fiber connected into my house and I have an existing phone wiring around the house (1 cable - 6 wires on it)

I have google it and as far as I know to get the 200mbps I only need 2 pairs of the 4 pairs (2 pair are not in use) and with 2 pairs i should be able to get 200mbps.

As a quick tests I connected my laptop directly to the router and all great I get the 200mbps.

then because my existing phone cable has only 6 wires I did the following tests.

The cable connected from my laptop to the router (cat 6)

1: I cut the blue wire (in theory unused) and immediately the speed went down to 90mbps

2: on a new cable (cat 6 always) this time I cut the white/blue the speed went down again to 90mbps

3: same tests I did with the brown and brown white, one at the time and always the speed went down to 90mbps.

4- if I cut any of the other wires I lose connectivity.

Question:

if only 4 wires are needed for speeds below 1gbps, why every time I cut any of the "unused" wires the speed drops to 90mbps?

are the tests I doing wrong?

Thank you in advance for your help 😀

White/Green

Transmit+

BI_DA+

Green

Transmit-

BI_DA-

White/Orange

Receive+

BI_DB+

Blue

Unused

BI_DC+

White/Blue

Unused

BI_DC-

Orange

Receive-

BI_DB-

White/Brown

Unused

BI_DD+

Brown

Unused

BI_DD-

CYaBro

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#2467448 21-Apr-2020 21:52

2 pairs are needed for 100mbs connection. Green and orange.
4 pairs are needed for gigabit.
There is no in between speeds by using 3 pairs.

Opinions are my own and not the views of my employer.

SomeoneSomewhere

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#2467450 21-Apr-2020 21:58

Two pairs (four cores) will get you 100BASE-TX, not anything capable of 200Mb/s. Plus, not all devices will properly negotiate down to 100Mb/s ethernet if both ends support gigabit but the cable is missing a pair. Standard gigabit (100BASE-T) requires all four pairs.

Beware that phone cable is not built to the same standards as Cat5 so you might have issues even with 100Mb/s over longer runs or where it runs alongside power.

There are newer standards for gigabit over single pairs intended to be used in industrial and automotive sectors, but normal networking equipment doesn't support them and you would still need Cat6A for them.

darylblake

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#2467451 21-Apr-2020 22:00

Yep sounds like not all the pairs working correctly.

All 8 cables / 4 pairs must be working correctly to obtain the speed.

So I would rewire, or get a cable tester. In MOST cases now days most units are auto-sensing, so Even if you did a crossover connection by mistake, the switch should work it out. :D

SomeoneSomewhere

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#2467454 21-Apr-2020 22:01

darylblake:

Yep sounds like not all the pairs working correctly.

All 8 cables / 4 pairs must be working correctly to obtain the speed.

So I would rewire, or get a cable tester. In MOST cases now days most units are auto-sensing, so Even if you did a crossover connection by mistake, the switch should work it out. :D

OP is trying to use existing 3-pair phone cable.

sbiddle

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#2467572 22-Apr-2020 08:18

There is no such thing as a 200Mbps Ethernet link speed - it's either 10Mbps, 100Mbps, or 1Gbps.

The cable you are using is cat3 rated with a maximum performance of 10Mbps because it is untwisted, and you should ideally be forcing your NICs to 10Mbps if you want the best performance. Under good conditions you can get 100Mbps from it but are also likely to see Ethernet performance issues over say 20m runs.

I'm not sure what you're reading that says you can get 200Mbps with 2 x pairs. This will only give you 100Mbps. You need 4 x pairs for Gigabit Ethernet to get 200Mbps.

antoniosk

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#2467576 22-Apr-2020 08:22

Based on OP's description, it looks like there's some good luck involved to get what he's getting, but it's also fragile because touching or cutting anything impacts the speeds.

________

Antoniosk

SomeoneSomewhere

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#2467808 22-Apr-2020 13:39

antoniosk:

Based on OP's description, it looks like there's some good luck involved to get what he's getting, but it's also fragile because touching or cutting anything impacts the speeds.

OP is testing with a Cat6 cable, not the Cat3 cable he's intending to use.

It's not exactly fragile; cutting cores is deliberate, not accidental.

Samsung

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antoniosk

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#2467892 22-Apr-2020 14:29

SomeoneSomewhere:

antoniosk:

Based on OP's description, it looks like there's some good luck involved to get what he's getting, but it's also fragile because touching or cutting anything impacts the speeds.

OP is testing with a Cat6 cable, not the Cat3 cable he's intending to use.

It's not exactly fragile; cutting cores is deliberate, not accidental.

good point, missed bullet 2.

________

Antoniosk

samgdan

160 posts

Master Geek

#2467945 22-Apr-2020 15:40

first thank you so much for all the responses. now things are much clear.

I will need to start investigating how to do some wiring around the house, alternatively I will need to look into using wireless..

Thanks 😀

SomeoneSomewhere

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#2468005 22-Apr-2020 18:10

100Mb/s ethernet, if it's working reliably over those links, is still not bad for an internet connection. It'll be better than wireless.

The thing to do will be to watch for packet loss.

samgdan

160 posts

Master Geek

#2470420 24-Apr-2020 16:37

I have configured two access points and it seems that they are doing well. I getting about 150mbps +- around the house.

this is for testing I have cables running around the house (cat6)

as now I know I getting good speed on wireless I will need to run a wire outside the house (I dont want the wires around the house)

I can see prices for 20 metres outdoor cat6 cables is about $60 while the standard cat6 cables for the same length about about half price.

Question:

What are the risks of running the standard cable outdoor? anyone can give me an estimate how long it will last? any performance impact?

Thanks in advance for all your help. 😊

cyril7

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#2470425 24-Apr-2020 16:54

Standard pvc sheathed cable is hydroscopic and will eventually take up water if exposed continuously the water changes the dielectric of the pairs which causes reflections which in turn creates packet loss.

If the cable is shielded from water so that it never sits in it for an extended period, and can dry when it's not raining then it may last for several years.

Also pvc will break down with sun exposure so eventually fracturing and again letting water in.

Cyril

andrewNZ

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#2470430 24-Apr-2020 17:04

I think you're approaching this wrong. There are some really smart cookies here, they can point you in the right direction from the get go.

How about just posting what you have and what you want to achieve. For example:
Could you replace the existing phone cable?
Do you have access to floor/ceiling spaces?
Is this permanent or temporary?
How many runs do you need?