Tag Archives: network interface card

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 gigabit 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?

What’s the Difference Between HBA, NIC and CNA?

HBA, NIC and CNA are three types adapters used in computer networking system. All perform to connect servers to switches, then what’s the differences between them? In this blog, knowledge of HBA, NIC and CNA will be provided.

HBA – Host Bus Adapter
Host bus adapter is a hardware device, such as a circuit board or integrated circuit adapter, that provides I/O processing and physical connectivity between a host system, such as a server, and a storage device. The HBA transmits data between the host device and the storage system in a SAN and relieves the host microprocessor of the tasks of storing data and retrieving data. The result of which is to improve server performance. HBAs are most commonly used in Fibre Channel (FC) SAN environments and are also used for connecting SCSI and SATA devices.

what is hba

NIC – Network Interface Card
Short for Network Interface Card, the NIC is also referred to as an Ethernet card and network adapter. It is an expansion card that enables a computer to connect to a network. Most new computers have either Ethernet capabilities integrated into the motherboard chipset, or use an inexpensive dedicated Ethernet chip connected through the PCI or PCI Express bus. A separate NIC is generally no longer needed. If the card or controller is not integrated into the motherboard, it may be an integrated component in a router, printer interface or USB device.


CNA – Converged Network Adapter
A converged network adapter (CNA), also called a converged network interface controller (C-NIC), is a computer input/output device that combines the functionality of a host bus adapter (HBA) with a network interface controller (NIC). In other words, it “converges” access to, respectively, a storage area network and a general-purpose computer network. The CNA connects to the server via a PCI Express (PCIe) interface. The server sends both FC SAN and LAN and traffic to an Ethernet port on a converged switch using the Fiber Channel over Ethernet (FCoE) protocol for the FC SAN data and the Ethernet protocol for LAN data. The converged switch converts the FCoE traffic to FC and sends it to the FC SAN. The Ethernet traffic is sent directly to the LAN.


What’s the Difference Between HBA, NIC and CNA?
In large enterprise companies, main servers usually have (at least) two adapters – FC HBA and Ethernet NIC to connect to the storage network (Fiber Channel) and computer network (Ethernet). CNAs converge the functionality of both the adapters into one.

As you can see from the picture below, with the set up in the first diagram, two separate adapters are required on the server to connect to Ethernet based Computer Network and FC based Storage Network respectively. But the set up in the second diagram requires just one adapter (Converged Network Adapter – CNA) which carries both Ethernet traffic as well as FCOE traffic in a single cable. This cable connects to one of the Ethernet ports in the Converged Switch that has both Ethernet as well as Fiber Channel ports. This Converged Switch converts the FCOE traffic in to Fiber Channel traffic to be sent to the FC SAN over the Fiber Channel Network. The computer network traffic is directly sent to the LAN over the Ethernet Network.

Compared to use both HBA and NIC, using a single CNA to connect servers to storage and networks reduces costs by requiring fewer adapter cards, cables, switch ports, and PCIe slots. Besides, CNAs also reduce the complexity of administration because there is only one connection and cable to manage. To connect CNAs to your ToR or EoR switches can over both SFP+ SR (optical) or SFP+ direct attach copper cable. To connect CNAs to your servers can over Cat6 cables. All these cabling solutions can be provided in FS.COM. All at low price and high quality!

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