Most of the markings on ethernet cables refer to safety certifications, standards bodies ratings, and similar things that won't much help much. The few things you might want to look for include:
Useful Markings
Category: CAT.5
, CAT.5e
, CAT.6
etc
As others have mentioned, the category listing is going to give you the most information. For modern data networking, you want at least CAT5e.
Be highly suspicious if there's no category listing.
More on categories below.
Category class: ENHANCED
This is sometimes used to indicate CAT.5e.
Pairs: 4PR
, 4PAIR
, 2PR
Indicates the number of pairs of wires. Modern ethernet cables are 4 pair (8 wires) but I have come across a CAT5e 2PR that was slowing down a network.
Shielding: UTP
, STP
, FTP
, S/UTP
, F/UTP
, S/UTP
Indicates the type of shielding, which can protect from interference. Unshielded (UTP) is fine unless the cable will be run through a particularly high interference environment like through the walls.
More on shielding below.
Wire Gauge: 24AWG
, 26AWG
, 28AWG
, 30AWG
, etc
Indicates the thickness of the individual wires. (Thicker wire = Smaller number.) 24AWG and 26AWG seem to be standard. A thicker wire might indicate higher bandwidth / speed capabilities as well as greater durability. I'd look somewhat askance at 28AWG/30AWG.
Speed: 350MHz
, 500MHz
, etc
Indicates manufacturer claims as to bandwidth performance. Should be taken with a grain of salt, as they're not always tested.
Cable Categories
Below is a summary of the ethernet cable categories and the preformance standards and bodies that apply to each.
Note, the bandwidth ratings per EIA/TIA are specified as up to the number listed. (As a range from 1 to x MHz.) However, they are in fact the minimum requirement for each class. I find this confusing, but there you go.
category bandwidth shielding speed EIA/TIA IEEE ISO/IEC 11801 use/notes
(MHz) (Mbps) (BASE-T)
CAT3 16 UTP 10 568B 10 Class C voice only
CAT4 20 UTP 16 10/100 obsolete
CAT5 100 UTP 10/100 568A 10/100 obsolete (-> 5e)
CAT5e 100 UTP 10/100/1000 568B2 1000 Class D networking minimum
CAT6 250 UTP/STP 10/100/1000 568B2-1 10GB Class E
CAT6a 500 STP 10,000 568C.1 10GB Class E-A
CAT7 600 S/FTP 10,000 10G Class F
CAT7a 1,000 S/FTP 10,000 10G Class F-A
CAT8.1 2,000 U/FTP, F/UTP 40,000 568-C.2-1 25G/40G Class I data centers
CAT8.2 2,000 F/FTP, S/FTP 40,000 568-C.2-1 25G/40G Class II data centers
CAT8.1 and CAT8.2 standards are under development.
Shielding Codes
These codes indicate shielding material to reduce electromagnetic interference. If present a screen is wrapped around each individual wire and/or the whole bundle of wires.
code meaning wrapping wrapping
(all wires) (each wire)
UTP Unshielded Twisted Pairs none none
FTP Foil Twisted Pairs none foil
STP Shielded Twisted Pairs none braid
S/UTP Screened Unshielded Twisted Pair braid none
F/UTP Foiled Unshielded Twisted Pair foil foil
S/FTP Screened Foiled Twisted Pair braid foil
Markings, Decoded
Here are some of the markings on cables I had laying around and their meanings.
E21220 Я⅃ AWM 2835 24AWG 60°C 30V TIA/EIA 268B.2 UTP CAT.6 RAPID CONN
Я⅃ AWM 2835 28 AWG/2PR 60°C 30V VW-1 ETL VERIFIED TIA/EIA-568B.2 CAT5.E UTP
ЯU
: UL (Underwriters Laborites) Recognized Component Mark
AWM 2835
: UL AWM Style "Multi-conductor, thermoplastic insulation and jacket"
28 AWG/2PR
28 gauge wire / 2 pairs of wires (4 wires total)
60°C
: temperature rating
30V
: voltage rating
VW-1
: UL Vertical Wire Flame Test (UL 1581)
ETL VERIFIED
: Preformance Certification from Intertek
TIA/EIA 568B.2
: ANSI/TIA/EIA Telecommunications Standard
CAT.5E
: Cable category 5E
UTP
: Unshielded Twisted Pairs
ENHANCED CAT.5 UTP 350MHZ CM 75°C 4PR 24AWG VERIFIED (UL) E201403 CSALL109448 ETL VERIFIED TO TIA/EIA 568-A PATCH CABLE
ENHANCED CAT.5
: Cable category CAT5e
UTP
: Unshielded Twisted Pairs
350MHZ
: Bandwidth
CM
: [Cable meeting UL 1581, Sec. 1160 (Vertical-Tray)][CM]
75°C
: temperature rating
4PR
: 4 pairs of wires (8 total)
24AWG
: 24 gauge wire
VERIFIED (UL) E201403 CSALL109448
: not sure, probably a UL standard
ETL VERIFIED
: Preformance Certification from Intertek
TO TIA/EIA 568-A
: ANSI/TIA/EIA Telecommunications Standard
PATCH CABLE
: ethernet cables are a subcategory of patch cables
I'm not an expert in this field, I just spent a bunch of time googling. Errors are entirely possible.
Google E244650 + cable, EN50173 + cable, and so on. If this is for home usage, I don't think it would matter anyway. If you're building a server farm, throw them all away and buy new ones. – Noam Kremen – 2011-09-18T21:06:08.753