Choosing the right cables for your data center

If you’ve read our top tips for managing data center cables, and let’s face it, you really should have, you’ll know that cabling is very important when it comes to data center infrastructure. Aside from having neat and tidy cabling, it’s also crucial to ensure your data center is using the right cabling.

Choosing the right network cable type is a big part of an effective data center cabling infrastructure, and quantity and quality are key points to consider when choosing. It’s also worth noting that different cables will have different specifications.

Things data center managers should consider before choosing Ethernet cables:

Bandwidth requirements

Manufacturers usually design cables so that the cabling system can carry higher bandwidth whilst avoiding issues arising from noise interference.

Your bandwidth requirements will influence which cables are best for your data center and the cable you’ll need for your applications. For example, Category 5e is made to support 10Base-T, 100Base-T and 1000Base-T (GbE) applications whereas 1000Base-TX applications will need Category 6 equipment. Similarly, if you are running 10GBase-T you’ll need Category 6a cabling, which is a minimum requirement for your data center to be IS0-certified.

Category 5

 

This cable is tested to 100 MHz and is suitable for applications of 10Base-T Ethernet, 100Base-T and 1000Base-T (GbE).
Category 6

 

This cable is tested to 250 MHz and is suitable for applications of 10Base-T Ethernet, 100Base-T and 1000Base-T/1000Base-TX (GbE).
Category 6A

 

This cable is tested to 500 MHz and is suitable for applications of 10Base-T Ethernet, 100Base-T, 1000Base-T/1000Base-TX (GbE), and 10GBase-T (10 GbE).

If you are opting for Category 5e, it normally offers a minimally compliant Gigabit Ethernet solution. They can be less expensive compared to other categories such as 6 and 6A but data center applications will seldom use 5e due to the essential performance requirements.

In contrast, Category 6 cable can manage voice, data and video simultaneously and works well with power transmission in Power over Ethernet (PoE) applications. They also have over twice the bandwidth and a tenth of the cross talk of Category 5e cabling.

Category 6A surpasses the performance of Category 5e and Category 6 cables with 10 GbE speeds but its larger cable diameter can create cooling issues if it blocks air flow. When planning to use 10 GbE network gear, make sure that the cabling solution is compatible with the network.

Your application requirements

Your cabling system may need to transmit concurrent multimedia signals. Your cabling requirements may also be influenced by the switching infrastructure. Usually this is designed to process application requirements so your cabling selection will be determined by the specified network infrastructure.

Physical space and port density

When choosing cables for your data center, be sure to consider port density. Nowadays, it is relatively cost-effective to configure your servers with four or more network connections and this has vastly increased the port density of each cabinet. Therefore, if you are a data center manager then it is a good idea to gauge your cabinet selection and cable management system as it will indicate whether you have enough space for Category 6a cabling.

Choosing fiber distribution methods

Whilst copper cabling is most prevalent in server-to-switch connections, fiber optic cable is better suited for backbone and long-haul applications.

Modern data centers increasingly have a higher amount of fiber cabling than they did previously. In fact, some data center managers prefer fiber-only networks as it can free up space, save on energy costs and can often provide management flexibility in large data facilities.

Speed and distance limitations for optical fiber cable can depend based upon the transceivers used on the cable ends.

Single Mode Fiber (SMF) Multi-Mode Fiber Cables

 

Gigabit up to 5Km with 1000Base-LX transceivers

10G is supported up to 40Km with 10GBASE-E transceivers

40G is supported up to 10Km with 40GBASE-LR4 transceivers

100G is supported up to 10Km with 100GBASE-LR4 transceivers

 

 

 

 

 

 

 

OM1 & OM2 Grade Cables

Gigabit up to 550m with 1000Base-LX modules.

10G is supported up to 300m with 10GBASE-LX4 modules.

OM3 Grade cables

Gigabit up to 550m with 1000Base-LX modules.

10G is supported up to 300m with 10GBASE-LX4 modules.

40G is supported up to 100m with 40GBASE-SR4 modules.

100G is supported up to 100m with 100GBASE-SR10 modules.

 OM4 Grade cables

Gigabit up to 550m with 1000Base-LX modules.

100G is supported up to 125m with 100GBASE-SR10 modules

10G is supported up to 300m with 10GBASE-LX4 modules.

40G is supported up to 125m with 40GBASE-SR4 modules.

 

Single Mode Fiber can often be seen as future-proof and can be reused for many years, so it can be an option for long-term data center planning.

When choosing cables it is important to choose cabling that can support future growth aspirations as replacing switches or modules on both ends of a link is an easy enough task but running new cabling when upgrading can be very labor-intensive and costly.

Summary

There isn’t really a perfect cable for everything and some will be better than others for various reasons, depending on your requirements.

In order to make wise cabling decisions for your data center’s next installation, try to consider what types of application will be running, your bandwidth requirements for them, your specified switching infrastructure, requirements for port density and of course your physical space restrictions.

Keeping these in mind will ensure you find the right balance between capabilities, suitability, and growth capacity to guarantee you choose the right cables to meet your needs.