Testing cable performance with a PC & loopback 2

[Slonarch]

Dear All,

I work in a harness manufacturing facility, and a client requested us to run a "connectivity test at 10 Mbit minimum" on a particular harness component which is a Cat5e cable. My understanding is that such tests are usually done with certification testers, but investing in one will probably eat half of our margin for the project.

Instead I ran a SpeedTest by RaccoonWorks having one PC as a server and another as a client, the whole set up successfully tested at 89 Mb/s (I didn't expect to get a 100). However, when I connected a loopback to the cable end and tested a much shorter patch cable using the same computer as both the server and the client, I only got 540 Kb/s. I am not an IT professional and can only speculate that the same processor/ethernet adapter has to switch between sending and receiving tasks.

Is there anything I can do to make the loopback test work as fast as the test with 2 computers?

Thanks!

 

[alamtnman]

What if instead of a loop back you tried a small mini hub so it was talking to an active device
To me there is no good substitute for a proper testing and certification. yes the testers are expensive and may eat up your margin but in the long run if there are problem's I would rather have the Proper test results and certifications to back up and guarantee my work.
how long will you be running the product and need to test,
Several places have leasing options and if you only need it a month or two that may be a solution to buying.
You might also just try to call some of you local cabling vendors with things as slow as they are in some area's a company might have a tester and even a person to operate cheaply just to give them something to do.
If this is a long term contract with chances to repeat and renew I would go ahead and bit the bullet and get the tester.


T.R.
RCDD

Honest officer,I know I've been thinking but i ain't thunk yet

 

[Servamatic]

If the client is asking for an application test, i.e. 10 Mb/s then a Test-um unit or some other validation tester will accomplish this for you.
While I strongly recommend actual certification in all cases, which is required for any manufactueres warranty, if the client only wants application validation, then the less expensive validation tester will meet your needs.

Richard S. Anderson, RCDD

http://www.servamatic.net

 

[oldtimerbob]

The expense for a good quality certification tester is more than worth the cost when spread over several jobs.
1. You can include a cable certification test cost in your esitmates, or charge a small fee ( we charge $5.00 per cable tested ).
2.They are good for troubleshooting any client's existing cabling and patch cords ( with any failing you can charge for the fixing or replacing).
3. The results on tests can be used for other problems that may happen in the future since most other trades always seem to blame the cabling for any of their failures.

Having one will also show to your clients that your company is professional in it's commitment to quality for the services provided.

Good Luck,

Has been in the cabling business for about twenty years and is now the Sr PM for a cabling company located in the Los Angeles area.

http://www.globusinc.net

Also a General Class Amatuer Radio Operator.

 

[Slonarch]

Dear All,

Thank you very much for the opinions. Based on the feedback, we decided to get a certification tester. We may get into building some fiber-optic assemblies as well, and it looks like a lot of testers nowadays have the capability to test fiber connections.

I tried to do some research on the best model and am extremely confused by the range of models on the market. Most don't seem to have much difference in functionality, but prices vary up to 8 times, the only correlation seems to be the brand. Can you please recommend an inexpensive line that does all the certification basics (we don't need to perform any network analysis or interact with any network devices - just test the cables)? Will Test-Um Validator/Validator Pro work?

Thanks again!

 

[Servamatic]

A validator is NOT a certification machine, validator are cheap for a reason, limited functionality.
Please do not confuse the validators and certification machines.
If it is not at least a Level III piece of test equipment it will not certify most of today’s requirements, i.e. Cat6.
While some call their tester a certifier, beware.
Fluke, Ideal, and Agilent make certifiers. Test-um does not. Certifiers are not inexpensive, but they are worth the money if you are in the cabling business. Any project that I manage you would be ineligible to bid on with owning at least a Level III certifying machine.


Richard S. Anderson, RCDD

http://www.servamatic.net

 

[SYQUEST]

Servamaic,

Please elaborate on what this Level III designation is, what is means, or provide a source for more information in order to understand its meaning and how it applies to test equipment. (Myself, I have never heard of test gear with a rating like this.)

....JIM....

 

[SYQUEST]

TEST-UM was acquired by JDSU in 2006. They have revamped the product line. The VALIDATOR™ series devices are "Certifiers" and there are more models available. If the product specifications are lying, they have a lot of explaining to do! Check it out here:

http://www.jdsu.com/products/communications-test-measurement/products/network-enterprise-test.html

....JIM....

 

[SYQUEST]

Sorry about the spelling, Servamatic! I wish Tek-Tips would add post editing!

....JIM....

 

[Servamatic]

Not a single one of the Test-um or JDSU devices is a Standards compliant certifier! They claim they can "speed certify" that is not the same thing as a TIA standards compliant certification.
For information about cable testing, try Flukes web site.

http://www.flukenetworks.com/fnet/en-us/learnAbout/Cable+Testing.htm

Again, if your client only wants to know that a cable is validated, you can use a validator such as JDSU, if your contract requires certification and a manufacturers warranty then they will not cut it.


Richard S. Anderson, RCDD

http://www.servamatic.net

 

[dagwoodsystems]

I'm sympathetic to your concerns about the cost of a certifier. You're not alone, which is why companies like Advanced Test Equipment and RENTELCO exist. They rent the kind of professional testers (including the Fluke brand) that may make sense for your short-term needs.

Tim Alberstein

http://www.dagwoodsystems.com

 

[SYQUEST]

Well, I guess Seramatic is right. JDSU Test-um division is not TIA/EIA certified! They base their measurement standards on IEEE 802.XXX requirements, but they don't print that or any standards reference in their data sheets yhat makes any sense! I called tech support @ JDSU and talked to a support person that sounded like he was reading from a script! He could not tell me why they don't use the TIA/EIA certification requirements for their products.

If you want the real thing, you spend $4K+ or whatever! (or rent one)

Well, from my perspective and the little research I did, it looks like a lot of "SNAKE OIL" is being sold in the form of test equipment that may or may not tell you any thing other than continuity or cable lengths. As the saying goes CAVET EMPTOR!

Do your homework!

....JIM....

 

[oldtimerbob]

For your information:

Agilent made the Wirescope but has ceased doing so, and will not give support for them in another year ( we were notified by them since we own two at this time ( they both test copper and fiber)).

We will more than likely go to the Fluke or Ideal with our next purchases.

Good Luck

Has been in the cabling business for about twenty years and is now the Sr PM for a cabling company located in the Los Angeles area.

http://www.globusinc.net

Also a General Class Amatuer Radio Operator.

 

[Servamatic]

Not good news about the Wirescope, since most contracts require them to be calibrated annually. Once the manufacturer will no longer calibrate them, they become an expensive toy.

Richard S. Anderson, RCDD

http://www.servamatic.net

 

[Slonarch]

Dear All,

I really appreciate everybody's help in figuring this out! It seems that most newer certifiers are designed for high-frequency (Cat6e and higher) applications. Since our client only uses Cat5e, it seems that something like a used Agilent Wirescope 155 or Wavetek IDEAL LT8155 (recalibrated) should be OK for now (the price range is under $1,500 for the unit itself + ? for calibration). By the time we start using Cat6, those testers will probably drop in price to a "less than a car" level.

Servamatic,

"Once the manufacturer will no longer calibrate them, they become an expensive toy."

There are 3-rd parties that claim they can calibrate Wirescopes, is there a lab certification that is typically required to verify the legitimacy of such claims?

 

[SYQUEST]

Yes, there are 3rd party metrology labs that should have the capability to do the same thing the manufacturer does. They just need to follow the certification requirements in the calibration process, and should provide a complete report showing the calibration results in print or whatever hard copy means they provide.

The manufacturer's maintenance manual and documentation should cover the calibration process.

....JIM....

 

[phonesaz]

I also am a fan of rent-as-needed. I use a little Siemons tester to check for problems - I have never had a new data drop pass the Siemons test and fail the Fluke test. My Fluke got stolen and I have only been paid to certify one job since then - rented a unit and it worked well. I was able to rent one from a local cabling buddy, but the ones listed here checked out pretty well. Just another opinion..