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
The following table contains the minimum Impact Acquire versions needed to use Balluff camera devices with RoCEv2 functionality:
| Windows® 64-bit | Linux x86_64 | |
|---|---|---|
| Supported | 3.5.0 | 3.5.0 |
RoCEv2 support and libraries on different Operating Systems:
| Operating System | RoCEv2 Support | API/Library | Deployment |
|---|---|---|---|
| Windows | yes | NetworkDirect Service Provider Interface (NDSPI) |
|
| Linux | yes | IBVerbs |
|
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 |
| Broadcom | P225P | ibverbs & rdma_cm from OS package management | 231.0.158.0 |
- Attention
- For Broadcom Ethernet Adapters the support for RDMA may be disabled by default. In these cases, support for the RDMA protocol must be explicitly enabled in the NVRAM of the network card using Broadcom's NICCLI command-line tool (see Enabling RDMA in the NVRAM via NICCLI or Modifying RoCE NVM Configuration Using NICCLI in the Broadcom Ethernet Network Adapter User Guide.
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 RDMA capable device by opening the device in ImpactControlCenter and check the mvStreamDriverTechnology property which must show RDMA (RoCEv2).
