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Posted

Hi folks, hope this is the right section for this.

 

Just for a bit of back story, the other day I cabled in a couple of points in rooms of the school previously off the grid. This involved ascending a million miles (roughly) up a ladder and fighting off giant spiders and mutants... and also, the main aspect of problem, a very long run of cat5.

 

I am definitely beyond the 100m to the switch but I have a link half way in a secure place at a patch panel on the wall.

 

I've heard from time immemorial there are devices out there to extend the range of cat5 but I cannot find much that's solid out there about them. I only need to extend the one cable. I'd DEFINITELY have run fibre if it were an option but sadly not.

 

Anyone ever been worked into this situation before and bought/used one? Any suggestions on what to get?

 

Thanks in advance to you for reading. :D

Posted

A switch installed will mean you can run 100m from the switch, by placing this in the middle means you can go to almost 200m from the main cabinet. In theory you shouldn't have more than 2 switches in any link back to the core, but in reality you can get 3 in if you really needed.

 

Skr

Posted

Also, keep in mind that "little switches" have a tendency to lock up and stop passing traffic. Problem is, by the time this happens, you (or your successor) may have forgotten that there is even a switch in this room. I'd suggest making a note of this somewhere appropriate so that when this room falls off the network you remember to restart this switch.

 

Chris

Posted
In theory you shouldn't have more than 2 switches in any link back to the core,

I don't think this is true (as the whole internet is made up of quite a lot of switches connected together and that works a lot of the time :) )

 

The 100m limit per segment is due to the time it takes the signal to zip up and down the cable and the inability to detect collisions.

 

Once you've stuck a switch in the path your OK again for another 100m.

 

The 100m is the recommend max for perfect conditions - try and stick your little switch half-way if possible (Not at 100m and then another run of 50).

 

As others have said - little switches do lockup - so bear that in mind. :(

 

regards

Si

 

PS Might be worth looking into pre-terminated fibre to see if its cost effective for you as that goes a lot further

Posted
I don't think this is true (as the whole internet is made up of quite a lot of switches connected together and that works a lot of the time :) )
I think you'll find they're called routers, and the reason for this segmentation is to reduce collisions on the network by creating smaller broadcast domains. Switches don't do this.

 

The 100m limit per segment is due to the time it takes the signal to zip up and down the cable and the inability to detect collisions.

The reason 100m is the limit is due to signal degradation over the distance. Same theory as USB.
Posted
I think you'll find they're called routers, and the reason for this segmentation is to reduce collisions on the network by creating smaller broadcast domains. Switches don't do this.

I think your words are better than mine on this :)

 

The reason 100m is the limit is due to signal degradation over the distance.

 

But I'll go the full half-hour on this one :)

 

Its basically down to the packet-size and the signals delays in xxBaseT cable from end to the other.

 

E.g A shouts a message - waits - doesn't hear anyone complaining that they are using the line and so carries on shouting. If B is more than 100M away and yells -Hey, I'm using the line - shutup - A won't hear it in time and carries on shouting. :)

 

If it was down to signal degradation you could just add amplifiers at each end to overcome this :)

 

regards

Simon

Posted
I think you'll find they're called routers, and the reason for this segmentation is to reduce collisions on the network by creating smaller broadcast domains. Switches don't do this.

 

The reason 100m is the limit is due to signal degradation over the distance. Same theory as USB.

 

switches do eliminate collisions and create smaller broadcast domains through microsegmentation and vlans on the up links respectively, that's my understanding anyway .

 

but i suppose the problem is that's fine as far as the switch level, but not on the uplinks where you can't microsegment every communication passing through.

Posted
switches do eliminate collisions and create smaller broadcast domains through microsegmentation and vlans on the up links respectively, that's my understanding anyway .

 

Switches eliminate collisions by having a single lan RX and TX pair for each link, this however does nothing for broadcast traffic as broadcast traffic is pushed out to all ports by the switch. You need to use VLANs or seporate switches to segment broadcast traffic and use routers to communicate between each of these isolated areas by filtering out broadcasts and directing traffic where it needs to go.

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