Cat6 Cables for Data Center Applications

The trend in network has always been leaning towards the higher bandwidth. Upgrading to a Cat6 cables (including Cat6a) system can ensure transmission speed and sustained performance for processing needs. Especially for data centers, investing into a higher-grade system will increase the network’s capacity and performance.

Cat6 Cables Overview

Conformed with EIA/TIA/IEEE standards, Cat6 cabling system includes patch cables, pre-terminated trunk cables, and bulk cables. For most first-class suppliers, their Cat6 Ethernet cables, involving Cat6a ethernet cables have 100% passed the Fluke Test, and deliver a specified testing report. Generally, Cat6 network cables adopt oxygen-free copper conductor with high electrical conductivity and low signal transmission attenuation. Being backward compatible with all the previous categories, cable UTP Cat6 and cable SFTP Cat6 both can be used to support up to 10 Gigabit Ethernet speed, and operate at up to 250MHz (Cat6a at 500MHz).

Cat6 Patch Cables

 

Cat6 Ethernet patch cables consist of Cat6, Cat6a, and slim Cat6 patch cables. According to length like 100ft Cat6 Ethernet cable, color, cable jacket, and shielding type, different Cat6 can be found in the market. Usually, the conductor of Cat6a and Cat6 shielded cable is 26AWG. The Cat6 unshielded cable is 24AWG, and the slim Cat6 is 28AWG. With a transmission distance up to 100m, Cat6 patch cables are widely used in data centers, network cabinets, offices to connect any data transmission equipment, such as PoE switches.

Cat6 Patch Cables

Figure 1: Cat6 Patch Cables

Cat6 Pre-terminated Trunk Cables

 

For Pre-terminated trunk cable, UTP Cat6 and SFTP Cat6a are available. Altogether, there are plug to plug type and jack to jack type can be found in the market. Generally, the conductor of jack to jack type is 23 AWG, while the plug to plug type is 26AWG. When it comes to the Cat6 cable price per meter, the plug to plug Cat6 cable price and Cat6a cable price are much higher than jack to jack types like jack to jack Cat6 UTP price. As for applications, Cat6 pre-terminated trunk cable assemblies are used to improve efficiency and reduce labor cost and waste in large infrastructures with high-density cross-connection and patching systems.

Cat6 Pre-terminated Trunk Cables

Figure 2: Cat6 Pre-terminated Trunk Cables

Cat6 Bulk Cables

 

Complied with IEEE 802.3af and IEEE 802.3at for PoE applications, most Cat6 bulk cables (including Cat6a) are about 1000ft (305m) lengths with spools. Their conductors are about 23 AWG. This Cat6 cable type is premium cabling designed for Cat6 or Cat6a applications, such as connecting an Ethernet wall jack to a router, patch panel or switch. With fast transmission and excellent signal quality, it ensures peak performance through your LAN.

Cat6 Bulk Cable

Figure 3: Cat6 Bulk Cable

Cat6 Cabling Application in Data Center

As we mentioned in the previous part, Cat6 cables consist of patch cables, pre-terminated trunk cables, and bulk cables. Each Cat6 cable type has its own features, which can be deployed into different scenarios. Here, we will take the integrated cabling of Cat6 pre-terminated trunk cable and Cat6 Ethernet patch cable types as a case to demonstrate its application in data center.

Cat6 Cabling Solution Case:

 

Cat6 Cables Data Center Application

Figure 4: Cat6 Cables Data Center Application

As the Cat6 wiring diagram shown above, we can find in this scenario, there are two racks in this data center needed to do cabling. And in each side, there is one FS S3900-24T4S switch. In that case, the first thing you need to do is to consider how to do Cat6 wiring and what’s the Cat6 wire order. Firstly, for the switch connection, the regular Cat6 patch cables will be used undoubtedly. As for connecting the two racks, the jack to jack trunk cable is suggested to use to do cross-connection. After that, cable managers and cable ties are recommended to deploy to keep the cables organized effectively. For suggested products list, you can refer to the following chart.

Suggested Products:

 

 Products List

Figure 5: Products List

Conclusion

As a cost-effective solution, Cat6 cables have been widely applied in all kinds of 1G/10G networks, especially in data centers. How to have a flexible and economically cabling system matters a lot to data center users. Hope this article can give you some inspirations.

10G SFP+ and 25G SFP28 Compatibility Analysis

In recent years, data centers are expanding at an unprecedented pace to drive the need for increasing bandwidth between the server and switches. 10GbE is not adequate bandwidth for today’s networks. There’s a tendency that 25GbE (based on SFP28) is on route to displace 10GbE (based on SFP+) from its leading role as the work horse in networking construction. As this transition takes place, questions about SFP+ and SFP28 compatibility arise for anyone who’s planning to upgrade the 10GbE to the higher and faster 25GbE. This post will provide a thorough presentation to 25GbE and clarify the compatibility issues between 10G SFP+ and 25G SFP28.

What Is 25G and Why Do We Need It?

25G Ethernet was based on the IEEE 802.3by standard and released in 2016. 25GbE specification makes use of single-lane 25 Gbps Ethernet links, providing a simpler path to future Ethernet speeds of 50 Gbps, 100 Gbps and beyond. By offering the advantages listed below, 25GbE is gained more and more momentum among service providers and data centers.

Backward Compatibility With 10GbE

The high performance 25G chips use single-lane 25G serdes technology similar in operation to 10GbE, supporting technology advancements from 10G in packaging and silicon. 25GbE allows existing switch architectures to support link speeds faster than 10G with no increase in cable/ trace interconnect.

Faster Network Performance

The 25G Ethernet based on the SFP28 form factor delivers 2.5 times more performance and bandwidth compared to 10G speeds. It also provides easy migration path to 50GE (2x25GE) & 100GE (4x25G), laying a path to higher networking speeds like 200G and 400G.

Significant Cost Benefits

25GbE delivers 2.5 times more data vs. 10GbE, thus reducing the power and cost per gigabit significantly. This power savings will in turn result in lower cooling requirements and operational expenditure for data center operators.

Available 25G Optical Modules and Cables

Every new Ethernet speed has gone through multiple pluggable form factor migrations to achieve higher density and lower power consumption goals. For instance, 10G moved successively to the X2 and XFP form factors before finally converging on the SFP+ form factor that allows for up to 48 ports per 1U. Similar form factor transitions happened for 40G (CFP to QSFP) and 100G (CFP, CFP2, CFP4 and QSFP), in achieving the highest density and lowest power. With the release of the 25GbE specification, 25 Gigabit Ethernet equipment is available on the market using the SFP28 form factors. For optical modules, FS offers cost-effective 25GBASE-SR, 25GBASE-LR, and 25G CWDM SFP28 transceivers to cut your hardware costs. For short-haul transmission, 25G SFP28 DAC (direct attach cable) and 100G QSFP28 to 4x SFP28 AOC (active optical cable) in various lengths are also available for all needs and specifications.

25G SFP28 DAC and AOC

10G SFP+ and 25G SFP28 Compatibility

With 10G and 25G Ethernet equipment coexisting on the market today, we may frequently encounter the compatibility issues related to SFP+ and SFP28 form factors. Anyway, the newer 25GbE technologies are backward compatible with 10GbE, allowing customers to build and cross-connect a heterogeneous-speed Ethernet network. Here we list the frequently asked questions coming through average customers.

1.What is the difference between SFP28 and SFP+?

The pinouts of SFP28 and SFP+ connectors are mating compatible. However, SFP+ is designed to operate at speed up to 10 Gb/s whereas SFP28 can handle 25Gbps, 10Gbps and even 1Gbps. SFP28 has increased bandwidth, superior impedance control and less crosstalk than the SFP+ solution. Besides, the SFP28 copper cable has significantly greater bandwidth and lower loss compared to the SFP+ version.

2.Can the SFP28 be used in SFP+ slot, and what speed will I get?

Theoretically, plugging an SFP28 transceiver or cable into the 10G interface is feasible for certain devices to get 10Gb/s data rate, but this solution is not recommended, because it would be limited by the NIC and switch port that you have. Only when your SFP28 module is 100% compatible with your server or switch can you ensure that the links can go seamlessly and efficiently.

3.Can the SFP+ be used in SFP28 slot, and what speed will I get?

Theoretically, plugging an SFP+ transceiver or cable into the 25G SFP28 slot is feasible. But you also need to make sure ensure that your existing modules will be compatible with your switch gear. That is to say, although a switch that accepts the SFP28 form factor can physically accept a SFP+ connector in the same port, it doesn’t mean that your SFP+ modules will work on your equipment.

Note: When shopping for new 25G leaf switches, if you have SFP+ modules you want to use, look for switches that accept the SFP28 form factor, which is physically capable of taking existing SFP+ modules. The same holds true for QSFP+ modules and QSFP28 ports. Carefully read the product specs to ensure that your existing modules will work with your new equipment.

Conclusion

As the majority of 25G switches and network interface cards offer backward compatibility to 10G, there is lots of flexibility to manage a gradual migration to higher speed servers and mix and match port speeds. Theoretically, all SFP28 based 25G ports on switches and 25G NICs can be used at 10G speed via port self-negotiation, but the premise should be that your existing modules are compatible with the NIC and switch port that you have. With a minimal premium for 25G based systems compared to 10G systems, it becomes a wise choice to deploy 25G capable systems to realize the performance advantages for migrations & future proofing initiatives.

Related Article:
10G – 25G – 100G Network Upgrade: An Inevitable Roadmap for Future Data Centers
FS 25G Portfolio for Data Center 25G/100G Leaf-Spine Network

How to Upgrade Cumulus Linux on N-Series Switches?

In the previous posts, we have introduced lots of details about Cumulus Linux, a network operating system. Also, we have talked about how to install Cumulus Linux on FS N-series switches like the 100GbE switch. In this post, we will solve another Cumulus Linux related question concerned by most of our users: how to upgrade Cumulus Linux on an N-series network switch?

Before Upgrading Cumulus Linux

Before any update, you should consider the migration and backup of some important data or files in case of any accident or emergency. In that way, being clear about the location of your configuration data is crucial before updating Cumulus Linux. Just like other Linux operating system distributions, the /etc directory is the primary location for all configuration data in Cumulus Linux. In the following figures, we list some files and as well as their directories that you are likely to do the backup.

Cumulus Linux Network Configuration Files

Figure 1: Cumulus Linux Network Configuration Files

Additional Commonly Used Files

Figure 2: Additional Commonly Used Files

Note: If you are using the root user account, consider including /root/. If you have custom user accounts, consider including /home//.

Upgrading Processes

Basically, there are two methods to upgrade Cumulus Linux: disk image install and package upgrade. According to different environment and preferences, the upgrade can be achieved in different ways. In this part, we will guide you on how to use these two ways one by one. By the way, if you are using MLAG to dual connect two switches in your environment, there are additional steps to follow. You can refer to the guide:Upgrade Switches in an MLAG Pair.

Solution 1: Installing A Disk Image

When you are performing a rolling upgrade in a production environment and using up-to-date and comprehensive automation scripts, the disk image installation will be recommended. It enables you to choose the exact release to which you want to upgrade. Moreover, it is the only method available to upgrade your switch like a 10GbE switch to a new release train (for example, from 2.5.6 to 3.7.0) or from a release earlier than 3.6.2.
To apply this upgrade, you need to use ONIE (open network install environment), which allows the installation of network operating systems (NOS) on a bare metal switch. FS N-series switches all include an ONIE installer. There are mainly six steps you can follow with:

1. Back up the configurations off the switch.

2. Download the Cumulus Linux image you want to install.

3. Install the disk image with the onie-install -a -i command, which boots the switch into ONIE. There are various ways to install the disk image, such as using FTP, a local file, or a USB drive. In figure 3, we demonstrate how to install image from a web server as your reference. After disk image installed, the switch can be rebooted.

Disk Image Install

Figure 3: Disk Image Install

4. Restore the configuration files to the new release—ideally with automation.

5. Verify correct operation with the old configurations on the new release.

6. Re-install third-party applications and associated configurations.

Solution 2: Upgrading Packages

Package upgrade is recommended if you are upgrading from Cumulus Linux 3.6.2 or later, or if you use third-party applications (package upgrade does not replace or remove third-party applications, unlike disk image install). When upgrading, configuration data stays in place. If the new release updates a configuration file that you changed previously, you are prompted for the version you want to use or if you want to evaluate the differences. Altogether, there are six steps as follows:

1. Back up the configurations from the switch.

2. Apply the following command to fetch the latest update metadata from the repository.

Command for the Latest Update Metadata

3. Review potential upgrade issues (in some cases, upgrading new packages might also upgrade additional existing packages due to dependencies). Run the following command to see the additional packages that will be installed or upgraded.

Command for Additional Packages

4. Upgrade all the packages to the latest distribution.

Command to the Latest Distribution

5. Reboot the switch if the upgrade messages indicate that a system restart is required.

Command to Reboot the Switch

6. Verify correct operation with the old configurations on the new version.

Questions & Answers

Besides the procedures to upgrade Cumulus Linux, we also list some questions concerned most by our FS customers.

1. How to Deal With Upgrade Failures?

Even the most well planned and tested upgrades can result in unforeseen problems. If you fail to upgrade Cumulus Linux, sometimes the best solution is to roll back to the previous state. You can refer to the following three techniques:

  • Back out individual packages: If you identify the problematic package, you can downgrade the affected package directly. In rare cases, you might need to restore the configuration files from backup or edit to back out any changes made automatically by the upgrade package.
  • Flatten and rebuild: use orchestration tools to re-install the previous OS release from scratch and then rebuild the configuration automatically.
  • Backup and restore: restore to a previous state, using a backup captured before the upgrade.
2. Will Future Software Updates for Cumulus Linux Be Free?

For FS N-series switches, the default validity of Cumulus Linux is one year. If Cumulus Linux OS is upgraded after 1 year, the customer can’t upgrade it for free and needs to renew the software support. Even if the software support service has been expired, you are allowed to use your current software as usual. By the way, we also provide a three-year software support fee option and a five-year software support fee option. The longer for OS support you choose, the more economical the switch will be.

3. Who Will Cover Technical Support?

FS will provide five-year tech support for the hardware. As for the problems about Cumulus Linux, FS and Cumulus will solve it together. Moreover, as one of the Linux distributions, the source code of Cumulus Linux is also freely available to everyone to use, modify or share such as GitHub. Just like the above question about the software update, the default validity of technical support for Cumulus Linux is one year. One year later, you can renew the support term.

Summary

In this post, we mainly focus on how to upgrade the Cumulus Linux on FS N-series switches. In addition, we list three after-sales related questions frequently asked by our FS customers.

Why 25G Ethernet Switches Are Still Necessary?

It has been about five years since the arrival of 25G Ethernet in 2014. For those years, the 25G Ethernet market has been filled with ups and downs. Facing with the broad adoption for 100G Ethernet and the upcoming new connection speeds of 200G/400G, the use of 25G devices, like the 25G switches, has been in doubt.

A Review of 25G Ethernet

25G Ethernet is one of the standards for Ethernet connectivity in a data center environment, developed by IEEE 802.3 task force P802.3by. Before 25G Ethernet was proposed, the next speed upgrade for data centers was expected to be 40G Ethernet (using four lanes of 10G) with a path to 100G defined as using 10 lanes of 10G. Now, with the 25G Ethernet standard, it supports to have four 25 Gbps lanes to achieve the speed of 100G Ethernet. In that way, it is said that 25G has paved the road for 100G.

25G Ethernet VS 40G Ethernet

Figure 1: 25G Ethernet VS 40G Ethernet

25G Ethernet Switch

With the 25G standard carried out, in 2016, its matching equipment was also available on the market, such as 25G SFP28 transceiver, DAC cable, 25G adapter, and 25GbE switch. Among those devices, the 25G Ethernet switch is the most representative one. Nowadays, the 25G switch market is mainly led by some branded vendors such as 25G Dell, Cisco, Juniper, Arista, and Mellanox switches. Usually, the 25G 48-port switch is the most popular type. Most 25G switches today offer two types of 25GbE interface form factors: QSFP28 that can support 4x25Gbps and SFP28 that can support 1x25Gbps. No matter for TOR (Top of Rack) switch or as the switch to deploy spine-leaf architecture, 25GbE switches will be the good choices.

Figure 2: FS 25G Ethernet Switch N8500-48B6C

Figure 2: FS 25G Ethernet Switch N8500-48B6C

Why Still Need 25G Ethernet Switches?

Switch Compatibility

The majority of 25G Ethernet switches in the market support backward compatibility. Because most of their matched optical transceivers are SFP28. And SFP28 is regarded as the enhanced version of SFP+, which is designed for 25G signal transmission. SFP28 utilizes the same form factor as SFP+, but the electrical interface is upgraded to handle 25Gbps per lane. As SFP28 adopts the same form factor as SFP+, SFP28 can connect with SFP+ ports and SFP+ transceiver can also connect with SFP28 ports. SFP28 is compatible with existing data center fiber cabling. Thus, you can greatly reduce the cost of re-architecture data centers and gain great flexibility in creating higher bandwidth during migration. To some extent, it can be both CapEx and OpEx savings.

Port and System Density

The 25G technology is similar to 10G, but the performance is increased by 2.5 times, thus reducing the power and cost per gigabit significantly. 25G Ethernet provides higher port and system density. For example, four 25 Gb/s data streams can be used to produce a 100G path over copper or fiber cable within a compact form factor. This approach also saves on energy consumption and requires fewer top-of-rack (ToR) switches and cables, which cuts much operational expenditure for data center operators in the end.

Price and Performance
Price Comparison by Connection Speed

Figure 3: Price Comparison by Connection Speed

As we can see in the Crehan forecast in figure 3, 25G delivers on both fronts with better price and performance. While 25G Ethernet is slightly more expensive than the 10G pricing, when valued with price and performance it is much cheaper on a per Gbit/s of bandwidth.

In fact, the 25GbE pricing is very competitive, with only a 30%-40% premium over 10GbE and this premium is expected to come down over time. To achieve these competitive pricing levels requires devices that are optimized to support 25GbE. In that case, deploy 25G devices, such as 25G Ethernet switches are necessary.

Summary

With the trend for higher Ethernet bandwidth, the demand for 10G Ethernet has been in decline. Before the 200G/400G Ethernet becomes mature, 25G shares lots of incomparable strengths to be considered as the proper choice to prepare for the upcoming migrations. In the context of that, 25G devices, such as 25 Ethernet switches are playing indispensable roles.

What Are the Commonalities of Switches Supporting Cumulus Linux

As the first full-featured Linux based operating system (OS), Cumulus Linux has injected great possibilities and new vitality in networking field in these two years. Due to its great effort in open networking, Cumulus Linux has been one of the three leading OSs in the market. The another two are IP Infusion OcNOS and Pica8 PICOS. Recently, the collaboration between FS and Cumulus Networks has been made. The N-series open switches from FS will be pre-installed the latest Cumulus Linux OS to customers. At the moment of their joint effort in achieving open networking, we are going to make an analysis of the similar features of the open manageable switch supported by Cumulus Linux.

FS Collaborates with Cumulus Networks

Figure 1: FS Collaborates with Cumulus Networks

An Overview of Cumulus Linux

Cumulus Linux is a flexible open network operating system, which can be installed on various open switches, including the layer 2 switch and layer 3 switches. The code used to build Linux is free and available for users to view or edit. Therefore, it looks like the world’s largest data center that allows users to automate, customize and scale using web-scale principles. After the installation of the Cumulus Linux OS, the open switch can act as a Linux server.

Cumulus Linux

Figure 2: Cumulus Linux

Similarities of Open Switches Supporting Cumulus Linux

Featured with supporting a broad partner ecosystem, the Cumulus Linux gives customers more options and flexibility in data center networking regarding switch type, CPU, chip type, and supported transceivers.

Switch Type

Generally, open switches that support Cumulus Linux are bare mental switches coming with open network install environment (ONIE). In that case, no matter you have a brite box switch like Cisco switch, or a white box switch like FS switch, Cumulus Linux can be accessible to them. Nowadays, in the market of open switches, the 32-port and 48-port switches with 40G/100G transmission speed are commonly applied by enterprise users. Considering their high-density and greater agility needs for networking, the open switches are mostly layer 3 switches so as to achieve spine-leaf or overlay architectures.

CPU

The open switch CPU that supports Cumulus Linux OS usually comes in three types: ARMv7, PowerPC, and x86_64. Among these three types, x86_64 is the most popular one, adopted by most vendors, such as Dell, HPE, Mellanox, and FS.

Chip Type
Chips of Open Switches

Figure 3: Chips of Open Switches

Currently, Broadcom chip and Mellanox chip are the major roles of switch chip. The Mellanox type is usually used by Mellanox itself or Penguin. Therefore, the Broadcom type dominates the largest switch chip market share, installed by the most brand vendors or the third party suppliers.

Supported Transceivers

Since most open switches support high-speed transmissions, the matching transceivers are QSFP28, QSFP+, and SFP28. Only some 10G and 1G open switches will need to use SFP+ and SFP transceivers. By the way, viewing the trend, you will find 25G Ethernet has been deployed by many enterprise users in recent years for high bandwidth need. Accordingly, the 25G open switch has been a more economical and efficient choice than 1G or 10G switches. Also, the 25G switch will be the best solution to pave the road for the upcoming 100G/400G Ethernet in the future.

Summary

Just like the agility and simplicity the Cumulus Linux has advocated, it brings a truly economical and open network environment for users. With so many choices for open switch type, CPU, chip, and supported transceivers, it liberates the choices for open switches, which begets an open networking market in the end.