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As I have understood Cat5E FTP (STP) cables support up to 1000mbps transmission rate. But I have seen them in stores that describe them of being capable of only 155mbps trx. Do both kinds exist? Or 1000mbps is only theoretical description? (given respective network hardware supports 1000mpbs communication)

Regarding '155mpbs':

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I edited your question to say UTP (Unshielded Twisted Pair) instead of FTP (File Transfer Protocol). There's no such thing as an "FTP cable". – Spiff Feb 24 '14 at 18:07
@Spiff FTP in cabling means Foiled twisted pair, where shield is foil. – astralmaster Feb 24 '14 at 18:21
@Spiff also referred to as STP (shielded twisted pair) – astralmaster Feb 24 '14 at 18:22
Can you post a picture or link to the cables you saw? My bet is that it's just a typo or confusion on the part of the manufacturer or whoever made the label and they meant 155 MHz. – David Schwartz Feb 24 '14 at 18:38
Yep, check my original post – astralmaster Feb 24 '14 at 18:40
up vote 4 down vote accepted

First, Cat5e is a UTP (Unshielded Twisted Pair) spec, not an FTP (foiled) or STP (shielded) spec

Gigabit Ethernet, IEEE 802.3 1000BASE-T, supports 1,000,000,000 bits per second signaling over Cat5 and better (5e, 6, etc. ) UTP cabling. After overhead, good software can get 941Mbps of TCP throughput out of that.

Sometimes cables talk about what frequencies they're rated for, like "200MHz". That rating is meaningless as long as it truly meets or exceeds the Cat5 specification.

It may be worth noting that network speeds are traditionally measured in 1,000's of bits per second (kilobits, megabits, gigabits), whereas disk and file I/O speeds are traditionally measured in 1,024's of 8-bit Bytes per second (KibiBytes, MebiBytes, GibiBytes). So 941Mb/s is roughly 112 MiB/s.

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Roger that, can there be a Cat5e cable that is 100BASE-T ? – astralmaster Feb 24 '14 at 18:24
@astralmaster A Cat5e cable is a Cat5e cable no matter what signals you run on it. You could use it as a POTS analog telephone line if you wanted. You can run 100BASE-TX over two pairs of Cat5 or better, whereas 1000BASE-T requires four pairs of Cat5 or better. – Spiff Feb 24 '14 at 19:11

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