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Standard User Mygri
(member) Fri 10-Apr-15 16:38:03
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Suitable Cable


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Hello,

We're looking to move to a different address with FTTC - good - and the owner has had network cable run to various locations - also good!. However, my preference would be for at least Cat 5e, but this, http://bit.ly/1z2mpMp , is what's actually been used. The printing on the cable reads "System Cable UTP 4 Pairs 24awg 169M"

I'm really not sure how good it is and I'd be grateful for any advice you may have.

Thanks in advance
Administrator MrSaffron
(staff) Fri 10-Apr-15 16:54:52
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Re: Suitable Cable


[re: Mygri] [link to this post]
 
CCA - copper coated aluminium - which is cheaper but not as good. My worry is that the box has no CAT5e labelling and cannot be any as the spec calls for copper core. So it may be fine at 100 Mbps but on longer runs you might find packet loss an issue quality of CCA varies a lot but push it for Gigabit to do local LAN streaming and probably issues.

Probably perfectly fine, but ideal world full copper core would be used.

http://www.blackbox.co.uk/gb-gb/fi/1234/11407/GigaBa... has copper CAT5e in boxes and if worried you could use the existing cable to pull through new full copper wiring.

The author of the above post is a thinkbroadband staff member. It may not constitute an official statement on behalf of thinkbroadband.
Standard User Mygri
(member) Fri 10-Apr-15 17:05:22
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Re: Suitable Cable


[re: MrSaffron] [link to this post]
 
Hi Andrew,
In reply to a post by MrSaffron:
CCA - copper coated aluminium - which is cheaper but not as good. My worry is that the box has no CAT5e labelling and cannot be any as the spec calls for copper core. So it may be fine at 100 Mbps but on longer runs you might find packet loss an issue quality of CCA varies a lot but push it for Gigabit to do local LAN streaming and probably issues.
As I suspected, and it's really Gigabit I'm wanting...
Probably perfectly fine, but ideal world full copper core would be used.
Indeed
http://www.blackbox.co.uk/gb-gb/fi/1234/11407/GigaBa... has copper CAT5e in boxes and if worried you could use the existing cable to pull through new full copper wiring.
Thanks for the link, however, everything I've read says absolutely NEVER pull through network cable - too susceptible to fracture...


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Standard User Pedrostech
(learned) Fri 10-Apr-15 18:02:34
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Re: Suitable Cable


[re: Mygri] [link to this post]
 
I've had gigabit speeds running over 200m of CCA 4 pair cabling before without any packet loss. There's certainly no harm in trying
Administrator MrSaffron
(staff) Fri 10-Apr-15 18:08:57
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Re: Suitable Cable


[re: Mygri] [link to this post]
 
Be interested to find out how people get it through ducting in buildings without pulling.

In my time have pulled long runs from out under stacks of muddy power and audio cables and it has survived and working at gigabit fine. I would give the wiring a good old test before panicking too much though.

Just use the possibility that it might need replacing in near future as a bargaining chip smile

The author of the above post is a thinkbroadband staff member. It may not constitute an official statement on behalf of thinkbroadband.
Standard User TheEulerID
(member) Fri 10-Apr-15 18:46:09
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Re: Suitable Cable


[re: MrSaffron] [link to this post]
 
At high frequencies the signal is largely confined to the surface of a conductor. As on the UK network the ANFP will only allow VDSL2 frequencies above about 2.2Mhz, the skin depth will only be about 44 micros (0.044mm). As long as the copper plating is at least that thick, the core material won't matter that much as the vast majority of the AC signal doesn't penetrate any further.

The skin effect is implicated in the increased distance-related signal attenuation with frequency. For very high frequency signals it's very common to plate surfaces with a more suitable metal.

nb. a Wikipedia article on the subject. There's an interesting table at the end that shows how the resistance of 24 gauge telephone cable changes with frequency due to the skin effect. At 1Khz it's 172 ohms/km, at 1Mhz it's 464 ohms/km and at 5Mhz 999 ohms/km. This has a strong bearing on attenuation losses.

http://en.wikipedia.org/wiki/Skin_effect

Edited by TheEulerID (Fri 10-Apr-15 18:52:53)

Standard User Mygri
(member) Fri 10-Apr-15 19:06:08
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Re: Suitable Cable


[re: MrSaffron] [link to this post]
 
In reply to a post by MrSaffron:
Be interested to find out how people get it through ducting in buildings without pulling.

In my time have pulled long runs from out under stacks of muddy power and audio cables and it has survived and working at gigabit fine.

Can't argue with experience - trumps theory every time. However, I well remember reading an article by a highly experienced network specialist, where amongst other woes he records

"Anyway, in the end it wasnít my dodgy carpal tunnels that caused the biggest problem, it was the fact that those helpful electricians had pulled through a lot of the cable runs, and as a result about four of the 16 cables had at least one of their conductors snapped inside the cable sheath. CAT-5 cable for wall trunking is solid-cored and therefore not all that flexible or strong. Itís meant to be laid, not drawn."
The full article is available at http://bit.ly/1CAiFSX.

Two contrasting experiences!

I would give the wiring a good old test before panicking too much though.
That seems the best course to me.

Just use the possibility that it might need replacing in near future as a bargaining chip smile
ditto.

Thanks for giving me some hope smile
Standard User Mygri
(member) Fri 10-Apr-15 19:08:58
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Re: Suitable Cable


[re: Pedrostech] [link to this post]
 
In reply to a post by Pedrostech:
I've had gigabit speeds running over 200m of CCA 4 pair cabling before without any packet loss. There's certainly no harm in trying
As per my response to Mr Saffron, I shall give it a go! Might be while yet before I can get my hands on it though.

Thanks smile
Standard User Mygri
(member) Fri 10-Apr-15 19:15:44
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Re: Suitable Cable


[re: TheEulerID] [link to this post]
 
Hmmm...

Had a quick glance at your link - there's some very deep reading to be done there - very interesting, but it might take a while!

Thanks smile
Standard User TheEulerID
(member) Fri 10-Apr-15 19:45:26
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Re: Suitable Cable


[re: Mygri] [link to this post]
 
The upshot is I think, if the copper is of a reasonable thickness, then it should be fine for VDSL2. Or, for that matter, g,fast or anything that comes along using higher frequencies.
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