Remote Direct Memory Access (RDMA) is network technology which allows data transfers with a very low CPU load on the participants system. RDMA over Converged Ethernet version 2 (RoCEv2) protocol is standardized as part of the InfiniBand Architecture Specification. It defines the InfiniBand Architecture over the Ethernet infrastructure, replacing the InfiniBand physical and link layer with Ethernet and UDP/IP. RoCEv2 offers hardware-offloaded, zero-copy data transfers with the following main characteristics:

High performance and efficiency
- Fully hardware-offloaded transport protocol
- Kernel bypassing technology with DMA
Reliability and data consistency
- Guaranteed packet delivery
- In-order packet and buffer delivery
- GigE Vision packet resend is not needed any more
Low latency
- UDP based
- Optional retransmissions handled in hardware, minimizing delays
Scalability
- Fully Ethernet speed agnostic
- Performance and efficiency scales with link rate
Industry proven standard
- Deployed in data centers and high-performance computing for years
- Adopted and supported by all major NIC vendors
- NIC vendor-independent standardized software APIs

RoCEv2 support and libraries on different Operating Systems:

Operating System	RoCEv2 Support	API/Library	Deployment
Windows	yes	NetworkDirect Service Provider Interface (NDSPI)	Network Service Provider Interface Interface is part of Windows OS Network Service Provider library must be supplied by manufacturer of the RDMA capable Ethernet adapter
Linux	yes	IBVerbs	Must be installed on Host by customer Major Linux distributions provide ibverbs and rdma_cm through their package management

Tested RDMA (RoCEv2) capable Ethernet adapters and appropriate drivers for different operating systems.

Vendor	Type	Linux Ubuntu 22.04	Windows 10 22H2 Client
Nvidia/Mellanox	ConnectX-4	MLNX_OFED_LINUX-24.04-0.7.0.0	MLNX_WinOF2-24_1_50000
Nvidia/Mellanox	ConnectX-5	MLNX_OFED_LINUX-24.04-0.7.0.0	MLNX_WinOF2-24_1_50000
Nvidia/Mellanox	ConnectX-6	MLNX_OFED_LINUX-24.04-0.7.0.0	MLNX_WinOF2-24_1_50000
Broadcom	P150P	ibverbs & rdma_cm from OS package management	231.0.158.0

The GigE Vision™ specification version 3.0 allows stream transmitters and stream receivers to use the RDMA technology in conjunction with the RoCEv2 protocol. Devices may support the conventional GigE Vision™ Streaming Protocol (GVSP) and/or RDMA streaming.

Note: The BVS CA-GT1 product family do support RoCEv2 streaming technology. Therefore a special firmware must be installed on the device, which will enable RDMA functionality and conventional GigE Vision™ streaming protocol will be disabled. If the host system and its Ethernet adapters are capable of RoCEv2, and a BVS CA-GT1 is running a RoCEv2 firmware, then the Impact Acquire host driver will automatically use the device's RoCEv2 functionality. Please contact https://www.balluff.com/go/contact, if you are interested in BVS CA-GT1 products supporting the RoCEv2 streaming technology.

You may verify the used streaming technology of a BVS CA-GT1 by opening the device in ImpactControlCenter and check the mvStreamDriverTechnology property which must show RDMA API.

RDMA API is shown in mvStreamDriverTechnology