Difference Between HBA, NIC and CNA

NADDOD Edward NIC Kit Engineer Jan 18, 2023

Fibre Channel host bus adapters (HBAs), Ethernet network interface cards (NICs) and converged network adapters (CNAs) are three types of adapters commonly used in computer and storage networks, and all three are designed to connect host systems to storage or network devices. So what are the differences between them?

What is HBA?

HBA stands for Host Bus Adapter, which is a board or integrated circuit adapter that provides the physical connection and input/output (I/O) processing between a server and a storage device. The use of HBA cards can greatly reduce the burden of data storage and data retrieval by the host microprocessor. Today HBA cards are used in a wide variety of interconnections, most commonly based on Fibre Channel, iSCSI and SAS protocols. there are different types of HBA cards depending on the supported protocols, such as FC HBA cards, iSCSI HBA cards and SAS HBA cards.

What is NIC?

NIC card is a network card, which is short for Network Interface Card, also known as LAN card or network adapter. It is an expansion board that connects a network device (such as a computer) to a server.

What is CNA?

CNA stands for converged network adapter, which is a converged network adapter, also called converged network port controller, or C-NIC for short. as the name suggests, this hardware component can combine the functions of an HBA with a NIC. On the one hand, CNA is equipped with PCIe interface that can provide connectivity and data transfer between storage devices or servers and FC SAN, and on the other hand it can directly transfer Ethernet traffic from the same network device to the LAN.


What is the Difference Between HBA, NIC and CNA?

The three different types of boards, HBA, NIC and CNA, all provide data processing and physical connectivity for network devices. However, they have unique functions and operating modes, and their application areas differ.

HBA: As mentioned above, different types of HBA cards have different transmission protocols. FC HBA cards are usually installed on HBA servers and connected to fiber optic switches via fiber optic patch cables; when FC SAN networking is used, FC HBA cards are required in most cases; iSCSI HBAs are usually used in IP SANs that use the iSCSI protocol and send data to storage devices on remote servers via TCP/IP networks. Send SCSI commands to the storage device on the remote server. iSCSI HBAs have RJ45 ports or optical ports, which can be connected to twisted pair or fiber optic patch cables. As for SAS HBA cards, they use SCSI command sets to connect SATA or SAS-compatible devices and are very popular in SCSI-enabled DAS networks.

NIC: Ethernet network interface cards work based on IP with two categories of optical ports or electrical ports. nic cards are usually connected to Ethernet switches via fiber optic patch cords or twisted pair cables. Most of the traditional NICs on the market today use iSCSI and NAS protocols and can be used in IP SAN and NAS networks, respectively.

CNA: Converged network adapter combines the functions of the previous two adapters into one, supporting both Fibre Channel (FC) and Ethernet protocols on a single port. Typically Ethernet is used for TCP/IP networks and Fibre Channel is used for storage networks. When using a CNA card, Fibre Channel is transmitted directly over Ethernet to the FCoE-enabled switch Ethernet port. The converged switch then converts the FCoE traffic to FC traffic and transmits it to the FC SAN, and the Ethernet traffic is transmitted to the LAN.


However, as shown above, if a network does not have a CNA card, the server must have at least two adapters - an FC HBA to connect the server to the storage network and an Ethernet NIC to connect the server to the LAN. therefore, in a data center SAN, a CNA card is preferred, which reduces the need for adapter cards, cables, and switch ports thereby reducing costs. Especially in high-density networks, CNAs can reduce multiple lines to one, greatly simplifying management.


In summary, it is easy to see that HBAs, NICs and CNAs all have their own characteristics and applications. The type of card you choose is not only related to the supported protocols, but will also depend on your network environment and budget.