A label with a lot to say
Look at the print on a drum of data cable. It says Cat 6a, a number in megahertz and the letters of a standard. Each part answers a question: how fast, how far and how noisy.
This lesson teaches you to read that print. The core course introduced the categories; here you read the whole table.
Key words
| Word | What it means |
|---|---|
| Category | a grade of twisted pair cable, such as Cat 5e or Cat 6a |
| Frequency | how fast a signal changes each second, in megahertz (MHz) |
| Data rate | how many bits a link can carry each second, such as 1 Gbit/s |
| Ethernet | the common way to join wired devices in an office |
| Deployment standard | the name of an Ethernet speed and cable type, such as 1000BASE-T |
| Mbit/s and Gbit/s | millions and thousands of millions of bits each second |
| Coaxial | a cable with a copper core and a braid screen |
| Standard | an agreed set of rules for how work is done |
The cells students fill in are left blank in this preview.
By the end of this lesson
Note
I can read a copper cable table and match each category to its frequency, length, speed and Ethernet name.
Starter: copper
Have a go
Starter: copper
3 questionsYour answers are marked here and are not kept. A college account keeps every student’s marks.
The copper table
| Category | Rated to (MHz) | Longest channel | Data rate | Ethernet name |
|---|---|---|---|---|
| Cat 3 | 16 | 100 m | 10 Mbit/s | 10BASE-T |
| Cat 5 | 100 | 100 m | 100 Mbit/s | 100BASE-TX |
| Cat 5e | 100 | 100 m | 1 Gbit/s | 1000BASE-T |
| Cat 6 | 250 | 100 m | 1 Gbit/s. 10 Gbit/s on a short run | 1000BASE-T, or 10GBASE-T when short |
| Cat 6a | 500 | 100 m | 10 Gbit/s | 10GBASE-T |
| Cat 7 | 600 | 100 m | 10 Gbit/s | 10GBASE-T |
The cells students fill in are left blank in this preview.
Decoding an Ethernet name
Take 1000BASE-T. 1000 is the speed in Mbit/s, so 1 Gbit/s. BASE means the signal uses the whole cable on its own. T means twisted pair. In 10GBASE-T the 10G is 10 Gbit/s.
So the name tells you the speed and the cable at once.
Coaxial in the table
Two coaxial types appear in older tables. RG59 is a thin coaxial cable used for CCTV and short video runs. RG6 is thicker, with less loss, and is used for TV, satellite and cable broadband.
Coaxial is not used for new office data. The distance it can reach depends on the signal sent, so always check the maker's sheet.