Thursday, January 17, 2008

CAT5e vs CAT5E vs CAT6 vs CAT6a

After much research, it appears that CAT 5E (big E) is a marketing ploy and doesn’t comply to any standards. It’s rumored to support 350MHz of bandwidth but I couldn’t find any real facts. Here are the actual standards:

  • Cat 5: Currently unrecognized by TIA/EIA. Provided performance of up to 100 MHz, and was frequently used on 100 Mbit/s ethernet networks. May be unsuitable for 1000BASE-T gigabit ethernet.

  • Cat 5e: Currently defined in a
    TIA/EIA-568-B. Provides performance of up to 100 MHz, and is frequently used for both 100 Mbit/s and gigabit ethernet networks.

  • Cat 6: Currently defined in TIA/EIA-568-B. It provides performance of up to 250 MHz, more than double category 5 and 5e.

  • Cat 6a: Future specification for 10 Gbit/s applications.

  • Cat 7: An informal name applied to ISO/IEC 11801 Class F cabling. This standard specifies four individually-shielded pairs (STP) inside an overall shield. Designed for transmission at frequencies up to 600 MHz.

This leads us to a question of price.

1000’ Cable (Plenum rated)$326.00$183.00
RJ-45 (Stranded)$0.73$0.25
Wall jack$6.39$3.20

Generally you can expect about 2x the price but will support 10x the speed (10GB). These prices are from a few sites on the internet and aren't by any means representative of all pricing. The general feeling from newsgroups and forums was that the expensive part was the labor so installing Cat6 was still the better choice if you have a new installation.

1 comment:

  1. A few facts about CAT5e...
    We have noted that CAT5e cable lengths can exceed the 300 foot limit and still maintain the throughput specifications... when the full 100 Mbps throughput was not required (50 Mbps or so) then it is prudent to note that we have used 450 feet successfully.
    Initially the CAT3 and CAT5 classifications related to the number of twists in the wire pairs per inch yet presently I note that they use differing twists for various pairs... some reversed and some not so tight.