not getting 1000MB throughput... dont know why

[mlchris2]

My Gigabit SX fiber transiever in my HP Procurve switch went bad, so I had to improvise and use the 100/1000 copper ports till I get a replacement. I'm not getting 1000 throughput between 2 switches after making the swap. I've dont all the config on the switches that I can, so this leads me to believe its cabling.

I am going from one switch port using CAT5 patch cable to a 66-punch block. I punched down all 4 pairs. From punch block its a 25-pair cable running approx 25ft to another 66-block. I the punch down 4 pair from a CAT5 cable to the other switch port.

My question is is the 66-block causing some sort of loss vs using a straight cable run from switch to switch?



Mark C.

 

[allisland]

Cat5 is not rated for gigabit to start, then what kind of cable is between the 66 blocks Cat3?
If it's that close buy a 80 or 100ft Cat6 patch cord as a temp run.

 

[mlchris2]

It might not be rated for gigabit but I've used CAT5 to connect switches together and get still get gigabit connectivity... but those cables were only 3ft long. But you are correct... CAT5 is not rated for gigabit.

IDK what the specs are on the 66-block cable. Just know its 25-pair, amphenol-style cable.

So it sounds like my assumptions were correct...



Mark C.

 

[lerdalt]

I know you can get gig over cat5 for very short distances. I'd bet you have cat3 running off of the 66 block.

 

[wires]

is the 66-block causing some sort of loss vs using a straight cable run from switch to switch?"

Yes.

You could try a cat6 or possibly a cat5e patch cable that would reach from one switch to the other. Should work.

Another issue is if you used a stranded "CAT5 patch cable to a 66-punch block" you should realize that punchdowns are designed for solid cable. Using stranded can result in all sorts of intermittent failures.

 

[SYQUEST]

A 66 type connecting block is NOT designed for RF signals, and that is basically what you have with hi-frequency data channels like Ethernet transmission. Using the arrangement you describe, you have completely UNbalalnced the transmission channel for the proper integrity of the signal. There is probably so much signal reflection and cancellation it isn't funny! That is why it does not work!

....JIM....

 

[mlchris2]

Great info from everyone. Thanks, I had a feeling the current "band-aid" was the cause.

Mark C.

 

[wires]

RF signals, and that is basically what you have with hi-frequency data channels like Ethernet transmission"

No.

Even at gigabit speeds ethernet is not RF since by definition radio signals are AC. Actually the symbol rate of 1000Base-T is the same as 100Base-T. The additional speed is gained by using all 4 pairs and coding.

http://en.wikipedia.org/wiki/Gigabit_Ethernet

 

[SYQUEST]

It is only a simplified analogy!! Put an antenna on it with enough power and you have RF!!!!!!!

....JIM....