Author Archives: Chloe Wang

How to Select Transceivers for White Box Switches?


White box switches, also known as bare-metal switches, have gained popularity in data centers. Because they provide high performance switching and enable users a broader choice in software and hardware purchase at the same time. However, it’s the openness of white box switches that leads to other problems: is there any limitation on the use of optic modules for white box switches? How to choose an optical transceiver for white box switches?

white box switches

Considerations When Selecting Transceiver for White Box Switches

As we know, white box switch vendors usually sell switches either as bare-metal devices or preloaded with any compatible operating system, as requested by the purchaser. And there are many hardware and software vendors on the market. In order to achieve the desired performance with white box switches, some users may purchase hardware and software from different vendors. For example, one network operator may buy a white box switch from Dell, FS or HPE, but he will get a network operating system from Cumulus Linux. There is no fault of this action, but it will bring another problem—which type of optical transceivers can be used for the switch?

optical transceiver

According to the situation of white box switches on the market, there are two considerations should be taken into account when choosing an optical transceiver for white box switches.

The first one is the operating system (OS) of the switch. It’s known to us that there are various OS vendors like Cumulus Linux, Pica8 and HPE. They develop their own OS for their white box switches to get more market shares. Some of these companies also have their own optical transceiver production line. And some of them do not preclude the use of any industry-standard transceiver, which provide a freely choice for users to source standard components directly from manufacturers or from a broad range of re-sellers. Therefore, the transceivers from the corresponding OS vendor can be used for their white box switches.

Another one is the optical transceiver itself. Not all white box switch vendors can provide transceivers for their switches. And some brand OEMs add enhancements to their standardized optic modules, which increases more cost on optics. However, some white box switch vendors look forward to seeing an open standard without vendor lock-in. Therefore, cost-effective compatible optical transceivers that follow MSA SFF specification is another choice for white box switches. Among these compatible optical modules, most generic optical transceivers on the market can be used for white box switches.

Optical Transceiver Solution for White Box Switches

White box switches have been the way for web-scale data center operators who are able to drive down the cost and drive up efficiency and flexibility of their IT infrastructure, especially in some big companies like Facebook, Google or Amazon. And there is a growing group of companies that also want the same level of efficiency web-scale operators have achieved. How to realize this? More white box switches are required without question.

Under this situation, providers like FS.COM supplies several types of 10G, 25G, 40G and 100G network switches preloaded with FS OS or Cumulus OS for small and medium size networks or data centers. And all the generic optical transceivers in FS.COM are available for white box network switches.

Connectivity Options Comparison for 10G Servers/Switches Networking

Much of the enterprise market is still running on 1GbE speeds and will be looking to migrate to 10GbE over the next several years. As we know, usually there are three types of connections between switches and servers in 10G networking—SFP+ DAC, fiber cables with SFP+ optics, and 10GBASE-T. And in theses connections, network interface card (NIC), also called network adapter, plays an paramount role. In this post, three connections that upgrade to 10G networking will be explored in details.

Connectivity Options

Today, IT managers can select 10GbE interconnect and switch options based on specific intended uses—using copper or fiber cables. Each has advantages and disadvantages. Here are the three connection options.

Fiber Cables with SFP+ Transceiver

Fiber optic connections are well suitable for areas that have heavy traffic aggregations like EoR (End of Row) switches. In these connections, SFP+ modules are used together with fiber patch cables, just like the following picture shows. In some SFP+ connections, SFP+ NIC is also needed to link servers and switches such as in MoR (Middle of Row) or EoR (End of Row) connections. Though cabling with fiber is great for latency and distance (up to 300m), it also costs more.


SFP+ Direct Attach Copper Cable (DAC)

Connections with DACs are a good choice for deploying 10GbE within blade server enclosures or racks over short distances. But its reach is limited to 7m and it is not backwards-compatible with existing GbE switches. Of course, an add-in 10GBASE NIC is required for these connections.


10GBASE-T NIC (Network Interface Card)

Nowadays, IT managers have 10GBase-T as a third option for either ToR switch or EoR usage models. 10GBASE-T with Cat 6a UTP cabling makes 10GbE available to a much broader market at a lower cost. It offers the most flexible solution for more data center 10GbE networking applications. Besides, 10G SFP+ copper transceiver also uses Cat 6a or Cat 7 copper cables, but it only supports link length of 30 meters.



As have mentioned above, 10G connections between servers and switches can be realized with both fiber and copper cables. Here is a simple comparison chart.

10G network

No matter fiber cable, 10G SFP+ copper cable or 10GBASE-T NIC, they can be used in ToR, EoR and MoR connections. Apart from the difference listed in the chart, another factor that should be considered is the cost. Even if the fiber cable has advantages on distance and latency, the use of SFP+ transceiver can add up to 30%-40% to server, switch and storage interface costs. And more SFP+ connections mean more add-in network adapters, which add cost and maintenance overhead.

While the raw cost of the 10GBASE-T is far less than either optical fiber or direct attach twinax copper cables. Cat 6a cable is easy to install and maintain, allowing for customized length, and it can be field installed. The most important point is that Cat 6a cable is compatible with existing 1GbE switches. Many networks today already have Cat 6 or Cat 6a cabling in place, so they are 10GBase-T ready. And today’s 10GBase-T network adapters are also cost-effective, enhancing the adoption of 10GBASE-T NIC.


10G Ethernet is no longer limited to fiber optic media. DAC cable is a popular choice for short distances; 10GBASE-T allows for more economical and easier deployment than ever before. With the price of 10GbE network getting more affordable than ever, many IT managers are sizing the opportunity to upgrade their networks and keep pace with these increasing bandwidth demands. After reading this post, fiber or copper, which would you choose?

Still Have Problems with Quanta LB4M and LB6M 10G Switches?

With the growth of virtualization, cloud-based services and applications like VoIP, video streaming and IP surveillance, various 10G switches with diverse functions spring out on the market. Quanta LB4M and LB6M 10G switches are two types popular 10G switches among them. However, there is few user manuals on the Internet, which brings inconveniences for users. This post intends to give a simple introduction to Quanta LB4M and LB6M 10G switches and some solutions for the common problems that may arise in their operating process.

Basis of Quanta LB4M and LB6M 10G Switches

The Quanta LB4M is a modular Gigabit Ethernet backbone switch designed for adaptability and scalability. This switch supports up to 48 Gigabit Ethernet ports to function as a central distribution hub for other switches, switch groups, or routers. And it offers 2 SFP+ interfaces for 10G port on the daughter board. While the Quanta LB6M switch provides 24 10GbE SFP+ ports and 4 1000BASE-T ports, which makes it more popular than LB4M. For these two switches, many users think highly of its performance. But there are also some passive remarks due to the limited documentation.

quanta lb4m & lb6m

Problem & Solution

If you have searched on the Internet, you will find that there are so many questions about Quanta LB4M and LB6M switches in all aspects like lack of instructive manuals, the operating issues, IP setup problems, etc. Here is a collection of several popular ones in discussion forums and blogs. Hope it will help you.

Quanta LB4M MAC Entry Problem

Use the LB4M in an active/passive configuration for SAN (Storage Area Networking). The two SAN nodes of the user have HA (fail over) and for that it uses a virtual IP which is moved between the two head nodes in case of failure. But the virtual IP MAC is missing from the LB4M switches “mac-addr-table”, which in turn leads to this virtual IP to be mirrored to all ports on that vlan.

Solution: right MAC (Media Access Control) mapping is the core of Ethernet switches. The first choice is to determine whether the MAC address of the switches is valid. Then pick a random address with the same 3-byte prefix as one of your physical MAC addresses and see if the switch accepts it. Another choice is to check the port security where the switch only accepts traffic from a single MAC address, either hard-coded in the config or the first one “seen” on that port.

LB4M Ports Are Deactivated and Backup Image Is Corrupt

Bought a Quanta LB4M and configured a management IP for the Web interface. After rebooting the switch as told, the screen showed that the crc-checksum for both the first and the backup image are corrupt, and another image is needed via the modem.

Solution: try to get upload an image via the modem to fix the problem. And then test it to check if the switch works.

Connect Dell 2848 with SFP to Quanta LB6M?

Dell 2848 switch has four SFP ports, while the Quanta LB6M has 24 10GbE SFP+ ports and 4 1000BASE-T ports. And other devices also need to be connected with. Then how to connect Dell 2848 with Quanta LB6M? The data center is currently running on a 1Gb Cat 6 cables.

Solution: using 10Gb SFP+ LC modules for the Quanta LB6M, 1Gb SFP LC modules for the Dell 2848 and then run MM fiber. Since SFP+ and SFP ports are not compatible, OEM services are another choice to solve this type of problem. FS.COM offers various kinds of customized service to meet customers’ different demands.

How to Avoid the Problems Mentioned Above?

It is undeniable that the Quanta LB4M and LB6M 10G switches are popular among users, which can be seen from the remarks in some forums. But since there is few instructive documents to describe these two types of switches, it will be difficult to solve the problems met in the operating process immediately. FS.COM supplies various kinds of 10G switches to meet the demand of Gigabit access or aggregation for enterprise networks and operators customers. Other 10G optics like 10G transceiver and 10G DAC & AOC are also available. Welcome to visit our website for more information.