When we had our extension built recently, I took the opportunity to install a Cat5 LAN. Well, to be more accurate, the electrician ran the cabling in but said he didn't do network wiring so the tails sat there for a while until eldest son got his new laptop. I got a friend who is an experienced network engineer with his crimping tool to install the face plates for the network points.
A diagram of the network is here:
formatting link
engineer had a wee gizmo that he plugged into the individual points and then another into the 4-gang which lit up to show that the wires were correctly connected. Everything seemed fine and dandy and, as I say, he's an experienced engineer.
Unfortunately the network doesn't work. A laptop plugged into any of the individual 1-gang outlets can't see the network. However, if it's plugged directly into the back of the router, all is fine.
Anyone any thoughts? I bought the cable from work (we do network installations, though I'm a software engineer myself) - it's unshielded twisted pair, and it's what we have in our work LAN.
When you plugged the laptop into the router direct, did you use one of the patch leads or another cable? Just a check to make sure you haven't got "cross-over" cable by mistake for the patch leads.
(But by posting here, I'm guessing that might not be an option!)
As others have said it might be that you're used cross-over cables, however every router I've seen recently has auto cross-over ports now, so it's unlikely that would cause a problem.
There are 2 "standards" for wiring cat-5 cable though - maybe he's using one and your patch leads use the other?
In addition to what the others have said ( incorrect patch cables ); can you unscrew the face-plates, and either take a picture or describe what wires have been punched down into which terminals?
I'd expect it to be:
1 Orange / White
2 Solid Orange
3 Green / White
4 Solid Blue
5 Blue / White
6 Solid Green
7 Brown / White
8 Solid Brown
( The Orange twisted pair may be swapped withthe Green twisted pair on some installations, that's OK )
What's important it the twisted pairs. One pair ( usually orange ) is used for pins 1+2. Another pair ( usually green ) is used for pins 3+6. This is critical. The blue pair and brown pair are only used on gigabit and / or PoE systems, but these are becoming commonplace, and should be wired up correctly too.
A common wiring error is to use one pair for 1+2, another for 3+4, another for 5+6, another for 7+8. This will not work properly.
It is essential that one twisted pair is used for 3+6, as described above.
That doesn't matter. So long as the wiring within a cable is the same at either end, then you can mix A and B patch leads and fixed wiring. A patch-lead or fixed wiring terminated using A at one end and B at the other will be a crossover cable.
The only diff is that the TX will be carried on the orange pair over one section, and the green pair over the next. And the RX will be carried over the green pair on one section, and the orange pair over the next.
The electrons are colour-blind.
So long as 1+2 are a twisted pair, and 3+6 are a twised pair, the actual colours used are irrelevant.
It would be interesting to know the make and model of the router. Others have suggested this might be due to the use of a crossover lead but most recent models should automatically compensate for transposed Tx and Rx lines. If this is the case then it wouldn't matter of one lead was a crossover anyway.
When you connect over the LAN there's 2 fly leads involved, one from the laptop to the individual faceplate and and another from the 4 gang faceplate to the router. Have you tested each lead individually, i.e. connect the laptop directly to the router with each one in turn.
Yes, I've tested each lead individually. Well, I've swapped them around and they all allow the laptop to connect directly to the router. I don't know if they're crossover patch cables or not - one says "CAT 5 PATCH CABLE UTP", the other says, amongst other things, "VERIFIED TIA/EIA 568A CAT 5 PATCH"
The router is a Netgear ADSL Firewall Router DG834. DCHP is on, natch.
A photograph of the back of one of the 1-gangs is here:
If the laptop works plugged directly into any of the router ports I'd get the wiring and socket outlets checked again. You can make a cheap test kit by cutting a patch cable in two and shorting out each twisted pair. Plug it in and stick the other half in the appropriate socket and use a continuity tester on each twisted pair on that cable. Either you have faulty wiring connections or the sockets are duff. That does happen. I have two needing replacement ATM because the RJ45 plug waggles about in them.
The router is in one room, connected to the 4-gang. The individual 1- gangs are in various other rooms on various levels in the house. The way I look at it (as a layman in the network game) is that the wire from the back of the router, via the patch cable, to the 4-gang and thence to the 1-gang is just a big extension lead.
Could have been much simpler to simply run a single wire from the router to a network switch which these days are cheap as chips for an 8 port. Unless of course there was nowhere to plug a network switch in where you have the connection box.
When I plug my laptop directly into the router, the patch cable carries the signal directly along the cable according to how the patch cable is wired.
However, if I plug the patch cable into the 4-gang wall socket, and an identical patch cable from the destination 1-gang socket into my laptop, surely the colour of the wires between the 4-gang and the 1- gang is irrelevant, provided that the two sockets are wired the same?
See this diagram that will probably only confuse the issue
No it really does matter. The signals are very small and they need protection from interference. Its done by twisting the two wires carrying the signal together. If you use one wire from one twisted pair and another from a different pair for a signal there is a lot of interference and it doesn't work This is what appears to have been done here.
2 should be orange and 1 should be orange and white as indicated by the colours on the socket.
In fact the brown + brown and white appears to be the only correctly wired pair.
The tester will still show it as correct BTW as it doesn't actually check the pairs are pairs.
snipped-for-privacy@hotmail.com coughed up some electrons that declared:
It's effectively a router without the routing part.
Which sounds assanine, until you get some base definitions:
hub - boost/cleanup of electrical layer signal, does not understand any protocol - no one really uses these anymore
router - is an IP endpoint for more than one network (ie it has 2 or more IP addresses of its own). It can "route" or transfer packets between networks using a rules table (aka "routing table") - the Internet is made of these.
switch - in between a hub and a router. Does no need an IP address (but may have one so you can manage it). If part of a network, knows or learns how to get different devices to talk to each other. Is actually a router at the ethernet frame layer (uses MAC addresses as base addresses, not IP addresses). Some switches have ability to make intelligent decisions about where to send packets (or not) by looking into the protocol and seeing if it's something they've been programmed to understand (eg HTTP, which is based off TCP which is based off IP which is based of many things, one of which is ethernet).
Fancy switches, like the big expensive ones made by Extreme and Cisco blur the distinction between router and switch and general implement functionality from both camps.
The long and the short of it is:
you generally have to set up a router, and you have a router as your incoming end of your broadband connection - there's one the other end, and maybe lots more between that and the news server you just read this message off.
you generally don't need to set up a switch for it to be useful, but you might if you're being fancy.
you don't set up hubs as a rule, but they're crap because for every packet you bang into one, it sends the same packet out all its ports. A switch learns the correct port to use, so is more efficient.
That may or may not be as clear as mud (blame the pear cider I just had).
When I plug my laptop directly into the router, the patch cable carries the signal directly along the cable according to how the patch cable is wired.
However, if I plug the patch cable into the 4-gang wall socket, and an identical patch cable from the destination 1-gang socket into my laptop, surely the colour of the wires between the 4-gang and the 1- gang is irrelevant, provided that the two sockets are wired the same?
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NO. You mis-understand a cruicial point.
The colours do not matter, ( the electrons are colour-blind) but the fact that the pairs are twisted do. Pins 1+3 MUST be from one twisted pair ( usually orng / orng-wht, but could be any colour ). Pins 3+6 MUST be from another twisted pair. ( usually grn / grn-wht, but again, could be any colour. )
This is absolutely crucial.
Also, the arangement of pins on the outlets varies from brand to brand. So you also need to take care of that. You need to read the pin numbers on the faceplates and punch the wires down using the colour-codes we have shown.
You just need to do what we say. Make the wiring at BOTH ends compliant with the standard we have indicated. Honestly.
I've installed these things more times than I can recount.
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