Network Categories Explained

A quick guide about different category standards

Network cables (also known as twisted pair data cables) come in different standards and classes. It's important to know which cables are needed for the appropriate application.

There are often misunderstandings in which category is needed, or "which is better" than the other.

 

We'll have a quick look at the following category (CAT) standards:

 

  • CAT5E
  • CAT6
  • CAT6A
  • CAT7/7A

CAT5E (also known as "Class D")

Earlier known as "CAT5", the Category 5E standard is used in domestic and commercial structured cabling networks.

The "E" stands for extended (which was added in 2001) as internal cross talk between pairs improved. You might come across a "CAT5" cable but in almost every case, it will meet CAT5E specifications.

 

Specifications

  • Frequency: 100Mhz
  • Bandwidth: 1Gbps over 100m (as required by the standard)

 

Application

  • Domestic and commercial networks
  • VoIP and basic telecommunication
  • Low bandwidth IP cameras
  • Digital audio transmission
  • DMX

 

Examples

CAT6 (also known as Class E)

The Category 6 standard was brought to life for transferring 1Gbps at 250Mhz, so double the frequency of the CAT5E standard.

Again, CAT6 is mostly used in commercial data networks but can also be used for video. Category 6 cabling is now pretty much the standard in all new constructions and building networks.

The main difference between CAT5E and CAT6 lies in the greater bandwidth and higher data transfer rates: you might be surprised to read that CAT6 also supports 10Gbps over shorter distances (up to 55m)

 

Specifications

  • Frequency: 250Mhz
  • Bandwidth: 1Gbps over 100m (as required by the standard) / 10Gbps over max. 55m

 

Application

  • Future-proof domestic and commercial networks
  • Digital Audio & Video
  • IP Cameras
  • HDBaseT

 

Examples

CAT6A (also known as Class Eᴀ)

Introduced a couple of years ago, the Category 6A standard is mostly used in data centers and applications where 10Gbps is needed over 100m. The transmission frequency has also been bumped up to 500Mhz.

CAT6A cabling is getting more and more standardized in healthcare and education. It also enhances PoE performance (in comparison to earlier categories) due to the higher power requirements for network components.

In many cases for new installations, CAT6A needs to be considered to render the network future-proof.

 

Specifications

  • Frequency: 500Mhz
  • Bandwidth: 10Gbps over 100m (as required by the standard)

 

Application

  • Data centers, high speed links (10Gbps) up to 100m
  • High bandwidth video (e.g. 4K)
  • High resolution IP Cameras
  • Digital Audio & Video

 

Examples

CAT7/7A (also known as Class F and Class Fᴀ)

Now, let's move on to the infamous "Category 7" cables. There are some issues with this standard as you might have noticed during the last years.

The CAT7 standard was brought to life in 2002 for networks to be able to transfer 10Gbps @600Mhz over 100m of copper cable.

People often get confused as they might think that CAT7 is better than CAT6 or CAT6A, the difference though lies in the connectivity: "true" CAT7 connectors (such as the TERA or the GG45) are proprietary connectors and are not compatible with the standard RJ45 foot print.

TERA Cable Connector
TERA Cable Connector
Nexans GG45 connector
Nexans GG45 connector

This means that terminating a CAT7 cable with a standard RJ45 makes no sense at all as you won't get full "CAT7" functionality unless you're using the proprietary TERA or GG45 connectors. Often the customer pays more for a "CAT7" cable but will get exactly the same specifications as a CAT6A link.

That's why in 2008, this CAT6A standard was ratified (almost like a revision of the CAT7 standard) in order to get the 10Gbps link speed over 100m (but at 500Mhz, which proved to be enough given the evolving quality of network components)

Please note that today, the Category 7 standard is not recognized in TIA/EIA.

Same thing goes for the Category 7A: introduced in 2010 for transferring future 40Gbps network speeds at frequencies of up to 1Ghz, it was never recognized by the TIA/EIA standardization. The 40Gbps proved to be working up to 50m.

 

Specifications CAT7

  • Frequency: 600Mhz
  • Bandwidth:
    • 10Gbps over 100m (with the use of TERA or GG45 connectors)

Examples

Specifications CAT7A

  • Frequency: 1000Mhz
  • Bandwidth:
    • 10Gbps over 100m (with the use of TERA or GG45 connectors)
    • 40Gbps over 100m but proved to be not capable (CAT7A)

Examples

Final thoughts

As structured network cabling is never an exact science, it's always difficult to come to a full consensus comprising every aspect of the infrastructure. Nevertheless, the next points should be somewhat helpful choosing your cable:

  • Overall, CAT5E cabling will do exactly what you need it to do for domestic use and office/commercial networks.
  • For new installations, installers should consider upgrading to CAT6 for future-proof purposes. The cost difference between CAT5E and CAT6 has decreased dramatically throughout the last years.
  • If you really want to future-proof your installation like for example the next 10 years, CAT6A should be seriously considered as more and more bandwidth is required to keep up with the growing quantity of data being transferred.
  • CAT6A should always be considered for high speed data links, such as data centers or critical network components demanding great bandwidth.
  • If you come across "CAT7", know you will be more than likely using it as a CAT6A cable, unless you're terminating with TERA or GG45 connectors.