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cat6 cables not working with cameras

post #1 of 26
Thread Starter 
I have an interesting problem, I made about 60-70 feet long Cat6 cables to use with PoE cameras. When I test the cables, the tester shows everything is perfect. When I connect the camera using this cable, it has the power (so PoE is working) but router does not see the camera. I used the same cable to attach my computer to the network, this case router sees the computer and I get an IP address.

I bought 100 ft ready to go cable and tried the same camera, it works without a problem. Does anyone know what am I missing? Are the cameras communicate different than computers so the computer gets an IP but camera is invisible to network using the same cable.

Thanks
post #2 of 26
Are you using EZ-RJ45 ends? If so, switch them out for regular ends.
post #3 of 26
Thread Starter 
Thanks for speedy response. Hmm, I think I am using regular RJ45 with a regular crimping tool. To be sure though, how is the easy one different? How can I know mine is not the easy one?
post #4 of 26
EZ crimp connectors allow you to pass the individual wires through the connector completely so you can see the colors more easily. Then, when you crimp the connector onto the cable, it also cuts off the strands that passed through the RJ45 connector so it is properly flush.

The problem with them, is they aren't as good as normal RJ45 connectors.

I would just reterminate the RJ45 connectors and ensure that every position is properly seated and that you are using the 568b wiring standard on both ends.

The is what an EZ45 looks like:
post #5 of 26
Thread Starter 
Mine are definitely the painful regular RJ45s. I did re-do the ends but I am not using the 568b, I just make pass through cable. Does that make a difference? Is there a performance/purpose difference between different coloured wires?

By the way thank you very much for your time.
post #6 of 26
Oh yeah - you MUST use 568b wiring for proper results! The cables are all paired a bit differently and they have different twists to them which affects performance.

Both ends should be wired just like this and that should take care of the issue:

post #7 of 26
Thread Starter 
Perfect, I will re-terminate them and see as soon as I can.
post #8 of 26
Thread Starter 
Done, re-terminated with 568b and cameras working perfect. Thanks a lot everyone.
post #9 of 26
Or 568A
post #10 of 26
Quote:
Originally Posted by fcwilt View Post

Or 568A
Interestingly, while this will work all the time with networks, it is not always the case with video connections, though I would expect it to be fine with security cameras.

I know at the high end with some HD-Base-T based products, there is a requirement to follow 568b standards. This is because the cable skew differences with the different types of cables are compensated for within the transmitters and receivers. They are looking for specific tolerances on very specific connectors, so the manufacturer specifies the 568b termination.

This is not universally required, but when a specific termination type is requested, it has always been 568b in my experience, so I recommend that people just follow 568b and not go with 568a in case reliability issues do arise with a specific product.
post #11 of 26
Well I'm no expert but what I have been able to find is that the TIA/EIA-568-B spec states that the T568A termination is the preferred but T568B can be used if needed (T568B matches a AT&T spec). Moreover the TIA/EIA-568-C is supposed to have deprecated the T568B termination.

Now video products like HD-Base-T are a whole different beast and I WOULD follow the manufactures recommendations.
post #12 of 26
Quote:
Originally Posted by AV_Integrated View Post

I know at the high end with some HD-Base-T based products, there is a requirement to follow 568b standards. This is because the cable skew differences with the different types of cables are compensated for within the transmitters and receivers. They are looking for specific tolerances on very specific connectors, so the manufacturer specifies the 568b termination.
Some HDBaseT products specify T568B, some T568A, and some T568A or T568B. IIRC a Category 6 cable can have up to 45 ns delay skew for networking purposes. This is much worse than the 1.78 ns max for a Category 2 HDMI cable. So, the receiver has to deskew, regardless of which channels it is between. It really doesn't matter which of the two standards you terminate to. I think most manufacturers pick one of the two in their literature to avoid having to field questions about which is the best way, and because of historical use in their markets. That said, if the manufacturer says a specific way, I would do it that way.
post #13 of 26
Quote:
Originally Posted by Colm View Post

Some HDBaseT products specify T568B, some T568A, and some T568A or T568B. IIRC a Category 6 cable can have up to 45 ns delay skew for networking purposes. This is much worse than the 1.78 ns max for a Category 2 HDMI cable. So, the receiver has to deskew, regardless of which channels it is between. It really doesn't matter which of the two standards you terminate to. I think most manufacturers pick one of the two in their literature to avoid having to field questions about which is the best way, and because of historical use in their markets. That said, if the manufacturer says a specific way, I would do it that way.

Interesting information! We know that the basic difference between T568A and T568B is just the orange and green pairs swapped. So electrically, they are identical - right?

But It seems that in CAT 6 the pair twist ratio between the green and orange pairs is slightly different which for Ethernet is a non-issue but can be a problem for HDbaseT?

It makes sense to me.
post #14 of 26
Quote:
Originally Posted by Glimmie View Post

Interesting information! We know that the basic difference between T568A and T568B is just the orange and green pairs swapped. So electrically, they are identical - right?

But It seems that in CAT 6 the pair twist ratio between the green and orange pairs is slightly different which for Ethernet is a non-issue but can be a problem for HDbaseT?

It makes sense to me.
The twist ratio affects the actual length of the wire inside the jacket. Each pair is twisted slightly differently, which doesn't affect Ethernet, but creates data skew which can (and does) affect HD-Base-T or similar technologies.

The green pair has 65.2 twists per meter.
The blue pair has 64.8 twists per meter.
The orange pair has 56.2 twists per meter.
The brown pair has 51.7 twists per meter.
(from Wikipedia)

I personally haven't seen anything call out 568A at this point, but I'm not disputing that some devices may call for it. I have never heard of 568C before. But, it appears to be unrelated to the actual termination. TIA-EIA-568-C is about standardizing a bunch of stuff related to cabling, but it does not (at this time) revise the T568A or T568B termination standards, so there is not a T568C termination standard that I am aware of.

Decent read here: http://en.wikipedia.org/wiki/TIA/EIA-568
post #15 of 26
Quote:
Originally Posted by AV_Integrated View Post

Each pair is twisted slightly differently, which doesn't affect Ethernet, but creates data skew which can (and does) affect HD-Base-T or similar technologies.
Yes, it does affect Ethernet. The signal is deskewed by the receiver. Works equally well whether the cable is terminated to T568A or T568B. HDBaseT is based on similar technology and of similar sophistication, and does the same thing. Lesser technology may not.
Quote:
The green pair has 65.2 twists per meter.
The blue pair has 64.8 twists per meter.
The orange pair has 56.2 twists per meter.
The brown pair has 51.7 twists per meter.
In what cable? The main difference between Category 5e and Category 6 is the tighter twist of the later required to achieve better cross talk numbers.
post #16 of 26
It seems to get the true answers to some of these questions someone will have to buy the standards documents.

I have read that the twists per inch are not part of the standard and that manufactures are free to use whatever they determine will provide the required performance.

I have read in several places that the T568B termination scheme is now deprecated.
post #17 of 26
Some older KVM extenders I used once specified CAT5 and specifically not to use CA5TE cable. But this was analog KVM and that's understandable. There are also a few companies that make or sell uniform twist CAT wire for analog video applications.

http://www.extron.com/product/product.aspx?id=enskfravutp&subtype=234&s=4

Of course this does not mean this cable is good for HDMI extenders as they may have built in delays and assume use of standard CAT5 or 6 cable.
post #18 of 26
Some Extenders (rare these days as the Installers had a freak) require that you leave the ‘pairs’ as is – this configuration is also discussed by Jeff Boccaccio on his HDMI training seminars as the preferred option but again very few, if any, current products go with it!

Our kit will do 568A or B as long as you stick with the same at both ends – not always the case going by some of the Tech support calls we receive!

We also get calls where folk just ram the cores into an RJ45 and crimp it with no thoughts about which cores are going where!!!

Joe
post #19 of 26
Quote:
Originally Posted by Colm View Post

Yes, it does affect Ethernet. The signal is deskewed by the receiver. Works equally well whether the cable is terminated to T568A or T568B.
I didn't know Ethernet receivers had skew compensators built in. I thought it was more about packet receive/error correction. But, I'm certainly not an expert. I definitely have seen products which require skew free cable, which have mostly been replaced by those which can use standard cat5/6 cabling.
Quote:
Originally Posted by Colm View Post

In what cable? The main difference between Category 5e and Category 6 is the tighter twist of the later required to achieve better cross talk numbers.
Sorry, was quoting from the cat5e article on Wiki...
http://en.wikipedia.org/wiki/Cat5e
post #20 of 26
Also- when you use cat5/6 cable for POE- you're locked in at 100mbs max throughput from two pairs because to achieve gb speed over Ethernet- all 4 pairs are used.
post #21 of 26
Quote:
Originally Posted by replayrob View Post

Also- when you use cat5/6 cable for POE- you're locked in at 100mbs max throughput from two pairs because to achieve gb speed over Ethernet- all 4 pairs are used.

No, PoE can be used with Gigabit Ethernet, as the power can be applied to the data wires (Ethernet operates as a differential signal above the DC voltage in that case). In 10/100 implementations, the PoE would have been on the spare pairs as you said, but that's not a limitation going forward...
post #22 of 26
Quote:
Originally Posted by Joe Fernand View Post

Some Extenders (rare these days as the Installers had a freak) require that you leave the ‘pairs’ as is – this configuration is also discussed by Jeff Boccaccio on his HDMI training seminars as the preferred option but again very few, if any, current products go with it!

Joe

Well what does "as is" mean? Here in the US we have T568A, T568B and USOC for CAT cables. They are all official standards so which one is considered correct? USOC is not used for networking but that still leaves T568A and T568B.
post #23 of 26
Quote:
Originally Posted by fcwilt View Post

It seems to get the true answers to some of these questions someone will have to buy the standards documents.
This? Don't have a link for the latest version. But the relevant information has not changed.
Quote:
I have read that the twists per inch are not part of the standard and that manufactures are free to use whatever they determine will provide the required performance.
That would agree with 4.3.3.2 in the link.
Quote:
I have read in several places that the T568B termination scheme is now deprecated.
I have, too. But I have read the opposite as well. Whether it is or not in the standard, it is going to be in use for the foreseable future.
post #24 of 26
10 zillion cat5/6 keystone jacks with labeling on them for 568A & 568B and not a lot of complaints from consumers... Yeah, this isn't likely to be changing anytime soon.

What I've heard is that generally residential setups go with 568B and commercial often uses 568A. I just don't know how much of a difference it really makes except in cases of companies which are using some legacy product.

I think that 568B got the nod for residential is because traditionally the green pair is used for line 2 in a home phone setup, but I'm totally going by what I remember hearing years ago, so any experienced knowledge on this I would love to hear about.

I haven't really heard about either 568A or 568B being deprecated at all. They both have their 'place' of use. I just know that when I read the A/V specifications for HD-Base-T products, or more often HDMI over cat-x extenders, they often call out specifically for a 568B termination. I've yet to see a call out for a 568A termination. I have seen many more which are just agnostic about it.

For example, Extron (who I would consider a major player in commercial A/V) uses an example of 568B in their terminations...
http://media.extron.com/download/files/userman/68-2370-50_A.pdf

But, their FAQ indicates that they are neutral on usage:
http://www.extron.com/product/faq.aspx?faqcat=13

Crestron indicates neutrality on this...

But, Monoprice specifically calls out 568B on their HD-Base-T extender (not sure if this is true or not for actual use!)...
http://www.monoprice.com/products/product.asp?c_id=109&cp_id=10110&cs_id=1011012&p_id=8122&seq=1&format=2
post #25 of 26
Quote:
Originally Posted by jautor View Post

No, PoE can be used with Gigabit Ethernet, as the power can be applied to the data wires (Ethernet operates as a differential signal above the DC voltage in that case). In 10/100 implementations, the PoE would have been on the spare pairs as you said, but that's not a limitation going forward...
Thanks for that info!
In this case I'm glad to be misinformed. I can see a need for a Gigabit switch with POE at my job- was kind of concerned about what I was going to do about it.... now I can rest easy.
post #26 of 26
Quote:
Originally Posted by Colm View Post

This? Don't have a link for the latest version. But the relevant information has not changed.
That would agree with 4.3.3.2 in the link.
I have, too. But I have read the opposite as well. Whether it is or not in the standard, it is going to be in use for the foreseable future.

Thanks for the link.

Supposedly it is the -C version that contains the reference to deprecating the T568B termination.

But as you point out folks are still going to use it.
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