Gigabit Cabling and Auto-MDIX Problems

Hi, I am currently attempting to upgrade from 100BaseT, with CAT5 at home and adding a new link with CAT7 cable, that I want to use for Gigabit Ethernet. I Bought two Telegaertner double AMJ45 sockets. For a first test I just cabled the two of them together straight through.

1 White/Orange 2 Orange 3 White/Green 4 Blue 5 White/Blue 6 Green 7 White Brown 8 Brown

At one end is a PC with an Intel 1000 MT Pro NIC, and the other end a new D-Link DGS-10008D, 8 Port Gigabit switch with Auto-MDIX. SO I have a patch cable from the switch to the first socket,then the cable run, then a short patch cable, then the PC. The switch has 3 other PCs connected,

2 at 100BaseT and 1 with the same Intel NIC again. All connected by short patch cables. The three PCs on the switch can communicate OK. I get a cable fault shown by the Switch when starting for the new cable run. I was the opinion that AUTO-MDIX would sort out any problems, at least with any patch cables. It certainly doesn't work at all.

Here is a link to the sockets I am using.

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The datasheet with the sockets shows two ways to connect them:

B:

1 White/Orange 2 Orange 3 White/Green 4 Blue 5 White/Blue 6 Green 7 White Brown 8 Brown

and A:

1 White/Green 2 Green 3 White/Orange 4 Blue 5 White/Blue 6 Orange 7 White/Brown 8 Brown

I guess this looks like a cross over. But shouldn't the AUTO-MDIX sort this out for me? I would be very gratefull for any insights, I want to add a few new sockets in the house and plan to use these sockets and this cable (its the same price as CAT5. Cheers Brian

Reply to
Brian
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Well it looks like the short patch cable to the NIC is bad. But I would appreciate knowing how exactly I should cable between the sockets, straight through in every case? Cheers Brian

Reply to
Brian

Yes, jack-to-jack connections should always be straight-through. If you need any conversion done, such as cross-over of any kind, it has to be done with an external cable (cord). It will make sense if you think about it: what if you need another cross-over, not 100Base-TX? You will need to re-wire the jacks, and more of the time they'll be inside the wall. So, by leaving any non-standard stuff outside the wall you'll do yourself a huge favor comes re-configuration time.

BTW, here are couple links for your reference:

10/100-Base-T crossover:
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Ethernet crossover:
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Reply to
Dmitri(Cabling-Design.com

Dmitri, OK, thanks for the reply. Yes it does make sense. Whats about the Auto-MDIX though, shouldn't it at least sort any cross-over vs. straight-through problems out? No doubt knowing what I am doing, and getting it correct from the start is better than letting some automatic feature try to sort it out for me. I assumed MDIX would at least free me from worrying about straight-through and cross-over patch cables.

Cheers Brian

Reply to
Brian

Well, it does take care of the conversion, but on the lower-end equipment you only have it on the uplink port, NOT on every port of the switch. On older equipment you don't have it at all, so it is better to stick with straight jack-to-jack connections just in case.

Good luck!

Reply to
Dmitri(Cabling-Design.com

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