CAT5e vs. CAT6

[Neoeclectic]

Does anyone have a link to a site that will show me benchmark performance ratings for CAT5e, CAT6, CAT6a, and CAT6e?

Thanks.

[KenB]

Quite a bit of info here: http://searchnetworking.techtarget.i..._Cablaggio.pdf

Ken

[tom]

Most of the datacenters use cat5 cable or cat6 cable nowdays?

[Neoeclectic]

Thanks for the doc link, Keith. That's exactly what I was looking for.

Tom,

CAT6 is considered to be the standard, but most data centers I've seen are still actively using CAT5e.

[Neoeclectic]

Hmm, I just read on this site that CAT6 has an operating limit of 220m, but other documentation I've read limits CAT6 to just 100m like CAT5.

Can anyone confirm/deny this?

[backpackets]

normally in data centre, we use cat 5e to patch devices(PDU,in row) connect to main switches.

for cat 6 ..we normally run from IDF to carriers rack/customer racks for VLAN/internet connection.

[Zitibake]

Originally Posted by alevin46

Hello Friends...........

Category 5e or Cat-5e cable is the evolution of the commonly used Cat-5 cable standard used to transmit data between electronic devices. ...
Category 6 or Cat-6 cable is the further evolution of Cat-5e cable. It is certified for use at gigabit (1,000 megabits) speeds

The way my old datacenter manager described it:
- Gigabit Ethernet was designed to work over the pre-existing Cat5 cable plant.
- There were some cases where Cat5 didn't work for GigE, especially at distances over 80 meters, and with many bends in the cable... extreme cases, but still within spec for a Cat5.
- The Cat5E standard was created in order to "fix" this, and a Cat5E cable plant will support Gigabit Ethernet at the full 100 meter distance, through any Cat5E standards-compliant cable pathway (basically, not too many bends, and not too tight).

...then people started dreaming about 10G...

- Cat6 was created with the goal of carrying the future 10G Ethernet standard.
- The 10G Ethernet standard came out, but it would not work properly on Cat6, except for short distances (such as inside a server cabinet).
- Cat6A was created, to successfully carry 10G to the full distance of 100 meters.

So:
- Cat3 is sufficient for T1 and 10mbps Ethernet
- Cat5 is sufficient for 100mbps Ethernet
- Cat5E is sufficient for 1gbps Ethernet
- Cat6A is sufficient for 10gbps Ethernet

...and Cat6 is left-out, being more than what is required for GigE, but less than what is needed for 10GigE. There may be some benefit from using Cat6 versus Cat5E, if you abuse your cables (tight bends, cable pinched in doors or between servers, etc.) And if you're doing 10G for short distances (inside a cabinet), then it may work. But it is an "orphan standard". Cat6 cables fill-up cable trays faster than Cat5E, without supporting any additional GigE standard. If you route your cables properly, there's no need for it on GigE. And people doing 10GE move to Cat6A instead of Cat6.

Feel free to correct me; this is just what I was told. For what it's worth, the cable manufacturers figured-out how to make Cat6 cable almost as thin as Cat5E cable (no "spine"); and some cable sellers quit carrying the bulk Cat5E cable altogether. So I often use Cat6 for 1gig Ethernet. But as far as I can tell, Cat6 has a very limited window of usefulness on technical merit. If you are trying to maximize the square inches in your cable trays, I believe that Cat5E is sufficient for 1GE.

[Zitibake]

Originally Posted by Zitibake

- The Cat5E standard was created in order to "fix" this, and a Cat5E cable plant will support Gigabit Ethernet at the full 100 meter distance.

I read through the Siemon brochure. It states:

Category 5e ...address the additional... performance ... required by ...1000BASE-T ... The Standard added headroom to category 5 ... required for support of Gigabit Ethernet over a worst case ...

.

...so that seems to support my old manager's assertion, that Cat5E was the "oops" release, to support GigE at "worst case" cable path. And that Cat6 is not (technically) needed to support GigE at all.

Another fun bit in the Siemon PDF was the opening assertion. It claims that the cable "category" standard (ANSI/TIA) always comes first; and then the IEEE Ethernet standard comes second, using the TIA Category as its basis. This argument was used in standards document TIA-942 to justify requiring Cat6 for all structured cabling within the datacenter. The claim was that it would "future-proof" your datacenter, enabling you to run protocols which were not invented yet. But what we've seen is that Cat6 was transitory, not future-proof. When 10GE was standardized, Cat6 was bypassed. And the fact that Cat6, which can't support 10GE, but is not needed by 1GE, somehow made it into the TIA-942 as a datacenter requirement, is evidence of the faith TIA has in cabling manufacturers, over IEEE. This is not healthy for the datacenter: how much money was spent globally, installing Cat6 structured cable plant, which was either not needed for GigE, or will soon be replaced to support 10GigE?