2 network questions! is the T568A Diagram necessary? Exchange 2007, rpc over http

[finbarqs]

I'm making some cables, and my friend tells me that as long as the cable matches up on both ends, it shouldn't matter what order they go in. Online, it says that you should follow the T568A, or use the T568B diagrams when making your cables.

Now I know all I need to do is to make the ends match up. But why does the diagram exist? why would we need to follow them? What benefits do we have using the T568x vs. just matching up at the end?

Another question is on my exchange server, I would like to use it over http. I don't have a SSL certificate, and I'm using outlook 2010. On my mobile devices, everything works great. But on PC's, it's like it wont work/connect. I'm using Exchange 2007. Anybody have any advice on this?

 

[Crusty]

YES it does matter. Split open a cable and look at the twist rates of the different pairs, they are different. Do NOT wire anything that is not standards compliant.

 

[RebateMonger]

There's a FAQ at the top of this Forum:
http://forums.anandtech.com/showthread.php?t=2053136

I don't know what kind of cables you are building, but consider what the FAQ says about crimping cables.

 

[drebo]

Orange-White, Orange, Green-white, Blue, Blue-white, Green, Brown-white, Brown.

 

[DnetMHZ]

Orange-White, Orange, Green-white, Blue, Blue-white, Green, Brown-white, Brown.

I hear that in my sleep sometimes..

 

[ScottMac]

Absolutely follow the EIA/TIA, your friend is an Idiot (at least for cabling).

Be advised there are "rules" beyond pair-ordering ... most significant are things like not exposing more than 1/2", and not untwisting more than 1/2" (the same half-inch for both, MAX) for Cat5, and 5E. At Cat 6, the 1/2" shrinks to 3/8" MAX.

There are specs for minimum bend radius (usually no less than 2" radius), pulling tension (varies with the cable, generally ~ 10-15 pounds of pulling strength), jacket compression (like no cables in tight bondage ... if you compress the sheath of the cable, it's "technically" out of spec), and proximity to noise sources, types of noise sources, proximity to metallic objects ... there's more, but you get the idea.

Maintaining the twist, no kinks/bend radius, and no stretching are probably the most critical. If you use staples to hold the cabling on a stuff, use staples that don't compress the jacket ("U" staples).

Good Luck

 

[finbarqs]

Why would the "just matching end to end" work then? what are the issues he may run into?

 

[spidey07]

Why would the "just matching end to end" work then? what are the issues he may run into?

It can "work", but the twisted pair is split and performance will be for shit. Forget about gigabit ethernet.

 

[Binky]

I've seen lots of cables that were crimped randomly so that they just matched at each end.

They always worked, somewhat. They never worked very well at higher speeds. Like spidey07 said above me, forget about gigabit performance on randomly-crimped cables.

Don't crimp if you can avoid it. If you must, crimp using an accepted standard (586B seems to be defacto).

 

[imagoon]

When you can buy 7ft machine crimped cables for 82 cents, why would you bother crimping at all?

Hell 30ft is $4.29

 

[spidey07]

When you can buy 7ft machine crimped cables for 82 cents, why would you bother crimping at all?

Hell 30ft is $4.29

There's that as well. There just isn't any reason at all to crimp cables. None.

 

[imagoon]

There's that as well. There just isn't any reason at all to crimp cables. None.

Basically. My RJ45 crimper has been in the box for a year. I use it only to crimp T1 stuff because our phone company decided to demarc on to RJ45 rather than 110 blocks for some reason.

 

[airdata]

white orange
orange
white green
blue
white blue
green
white brown
brown

 

[spidey07]

Basically. My RJ45 crimper has been in the box for a year. I use it only to crimp T1 stuff because our phone company decided to demarc on to RJ45 rather than 110 blocks for some reason.

You mean RJ48

<---runs

 

[imagoon]

You mean RJ48

<---runs

Nope, seriously RJ45. There is no loop back shunts in that panel nor provisions for shielded cable. Also need to pull off the "wrong pins."

 

[spidey07]

Nope, seriously RJ45. There is no loop back shunts in that panel nor provisions for shielded cable. Also need to pull off the "wrong pins."

Tell your phone company about bellcore. They need to learn it.

 

[imagoon]

Tell your phone company about bellcore. They need to learn it.

Yeah... if it "works" they won't touch it. Phone companies are spawn of whatever you find unholy.

 

[drebo]

Another question is on my exchange server, I would like to use it over http. I don't have a SSL certificate, and I'm using outlook 2010. On my mobile devices, everything works great. But on PC's, it's like it wont work/connect. I'm using Exchange 2007. Anybody have any advice on this?

Because the certificate was generated by an untrusted source, you need to add that certificate provider to the client manually. You then need to add the certificate to the client manually as well. There are docs for how to do this.

Tip: go buy a $14.99/yr SBS Instant SSL certificate...way easier.

 

[JackMDS]

There's that as well. There just isn't any reason at all to crimp cables. None.

Well in the last decade, the trust of our society changed from being enterprising people to Whiners that operate on the excuses principle.

As a result doing things that would eventually will cause trouble is a good thing.

That ensures constant source for Whining.

 

[arch113]

white orange
orange
white green
blue
white blue
green
white brown
brown

For some reason we use:

white green
green
white orange
blue
white blue
orange
white brown
brown

 

[spidey07]

For some reason we use:

white green
green
white orange
blue
white blue
orange
white brown
brown

That's 568a, normally used outside the US. US uses 568b.

 

[arch113]

That's 568a, normally used outside the US. US uses 568b.

Interesting... I am not outside the US, just what I was taught when I started here 12 years ago