Cat 5 hardware.

I was at Greybar (electronic supplier) to buy some connectors and rj45's. I am using them on an Ethernet cat5 network. My question is what is the difference in a regular rj45 and a cat5 rj45 beside the price? They look the same to me.

 

Good question. Have installed many networking cables n had the same question. As you know anytime a connection is made it can become a problem. Doesn't matter if telephone, network or anything else. Connections are a sore spot. Apparently most CAT 5 connectors come gold plated to avoid corrosion. So do some regular RJ45's. Check to make sure it's gold plated. That's the only difference, which doesn't always exist-- so check.

Else it's just a solid wire connecting 2 things.

 

That is the first thing I checked. Both Cat5 and telephone were cold plated, the connector and the jack.

 

RJ45 is a physical connector
Cat 5 is an ANSI standard for data transmission across twisted pair cable.

Phones use a RJ11 connector between the phone and the wall. Ethernet uses an RJ45 connector to hook computers, hubs, routers etc.

You can place an RJ45 connector on any 8 wire cable, but that doesn't make it a cat 5 cable. Only cable that can support 100 Mbps is designated Cat 5. The different categories are listed here. Any ethernet cable you buy today should be Cat 5 or better.

In my experience, gold plating makes little difference on ethernet cables.

ICE

 

RJ45 is 8 or 10 conductor connector and jack. RJ11 is 2,4, or 6 conductor connector or jack. They are for two different things. On the telephone side RJ45 is used for Merlin, ISDN, and several other applications where Cat5 wire is not required. Whereas Cat5 is used in Ethernet networks and uses only 6 conductors on the 8 conductor wire but the standard connector for Cat5 has become RJ45 connector and jack. My question is why should I pay twice as much for a RJ45 connector rated for Cat5 when the regular RJ45 connector appears identical?

 

I interpreted your original question as referring to cable and connector rather than just connector....now that I know you are referring to only a the connector I'll say this....

Of all the places I've bought RJ45 connectors I've never noticed or bothered with a Cat. reference. My entire house is networked with self installed cable runs, jacks and connectors and I honestly couldn't tell you if my RJ45's meet any sort of CAT spec. I've never had trouble with any of them.

Since all the connector does is interface the cable to a pin, I suspect the quality of the connector itself is more important than any sort of CAT rating. As I browse the web I do see some RJ45s advertised as Cat 5, Cat 6. Can't tell you what the difference is, maybe someone else knows...I'd be intereseted to find out myself. I'll also ask around at work tomorrow.

Cheers,

ICE

 

Hey Ice: I followed that link you provided, and see the Cat1 cable for POTS delivering 1mbps. Which raises this question:

My computer and two others here are wired to a DSL Modem with a Cat5 cable.

The DSL Modem is wired to a POTS jack with Cat1 cable.

The computer is connected at 100mbps (per Windows) and the modem is connected with a Cat1 to the local telephone service at 1mbps.

If the signal is coming in at 1mbps, how could the modem be delivering 100mbps to the computers?

I'm sure there is probably a simple explanation, something I am missing?

Martin

 

I would assume that you probably have a hub, switch, router etc. My theory is that windows is reporting the connection speed between your machine and the hub.

Your two machines can have 100 Mbps when talking together, but any transmission through the DSL modem is limited to the 1Mbps cap on your DSL line.

For example, My 1Mbps DSL connection hooks to my Linksys router and 5 other machines. The traffic within my network runs at 100 Mbps (in theory, anyway) but traffic going through my DSL line is limited to the 1 Mbps that I have.

Cheers,

ICE

 

martinr121, my understanding of DSL over the phone line is that the 1mps is an analog measurement. Regular telephone works on analog but DSL is a digital signal over top of the analog. For this reason the 1mps does not apply. 100mps on Cat5 wire is also an analog measurement. This is also true of cable, although coax can transmit analog at a much faster rate than wire, up to a point, then you need to get optical fiber. The modem (DSL or Cable) converts the digital signal to analog.

 

This was original discussion about connectors-but-since it's expanded will toss in a nickel worth of thoughts over cables.

Always always buy shielded cables. They cost a bit more but well worth it. Otherwise a screwy fish tank pump (to say nothing of florescent lights n ballast resistors) may cause all kindsa intermittent problems if cable too near them.

You can buy cat 5,6 cables both sheilded n unshielded. Get the shielded.

Shielded cables for twisted pairs is standard and a LOT less expensive if simply go to a cable manufacturer n buy them there rather then a computer store. Just match up the gauge of wire.

That assumes you're terminating the cables yourself n have the tools. If just doing a bit of home networking a computer store is easier n quicker.

 

Well,

I enlisted the brain trust at work and suffice to say they have no clear definition of the difference between a plain RJ45 and a 'CAT 5' RJ45.

Through searching and examination of varius RJ45 connectors we have noticed only one significant difference. Bear in mind this is entirely speculation.

It appears that on 'CAT 5' connectors the area where the connector crimps to the cable jackect is slightly rounded. Other RJ45s have a flat crimping surface.

The theory is the 'CAT 5' connectors are curved to accomodate the rounder shape of a CAT 5 cable, while the other connectors are flat to accomodate the flat 8 wire cable that phone systems and ISDN may use. One might suppose that the 'CAT 5" connector's round crimp point serves to limit the crushing effect of the crimp on the cable.

Of course, this enitre theory could be complete garbage. But it's all I've found so far. None of my N+ books mention any difference between RJ45 connectors.

Cheers,

ICE.