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RoCEv2 and Testing Disaggregated Storage Ethernet

2021-04-08  |  5 min read 

Pretend she is in a lab testing network gear and not building an unshielded cryptomining rig. #stockphotography #nofilter

Demand for data, and in particular storage for that data, is ever growing. One way that organizations have been trying to cope with these ever-growing needs, RoCEv2, RDMA over Converged Ethernet version 2, is a routable, internet layer protocol that works over either converged or traditional Ethernet networks. RDMA, remote direct memory access, enables data transfer directly to or from the wire and application memory. This is useful in that it reduces load on the CPU while reducing latency – key to greater overall performance, particularly in storage networks. There are other ways to implement RDMA, including InfiniBand (RoCE is actually encapsulated InfiniBand), Virtual Interface Architecture and iWARP, but we’ll stick to RoCEv2 here. RoCEv2 runs over UDP/IPv4 and UDP/IPv6 (port 479).

One of the first things you might ask is what is the difference between RoCE and RoCEv2. Probably the biggest difference is in routability and thus scalability. RoCE is not routable – all communications must remain in the same broadcast domain. RoCEv2 is routable and benefits from all the advantages in scalability that come with it.

Testing RoCEv2

Two of the biggest considerations for RoCEv2 are realism and performance.

Realism

Testing RoCEv2, like most other forms of network testing, is improved by running more realistic tests. The closer your tests resemble real network use patterns, the more meaningful your test results will be.

Performance

RoCEv2 is a stateful protocol. It requires significant processing power to generate line rate traffic. Additionally the congestion control mechanisms in RoCEv2 require very fast replies to control packets.

Ideal Test Solution

With these things in mind, the ideal test solution would be one that would combine both realism and performance and that is where IxLoad and the Data Center Storage load module for the XGS Chassis come in.

IxLoad

IxLoad is Keysight’s L4-7 performance testing software for multiplay services, application delivery platforms and network security appliances. It is IxLoad that brings the realism to the test.

Data Center Storage load module

With a generous helping of multi-core, multi-threaded CPU to address the need for stateful line rate traffic and FPGAs to address the need for fast replies to control packets, the Data Center Storage load module provides the computational speed and power in order to make testing RoCEv2 at scale a possibility.

But will it scale?

The answer is yes. A fully loaded XGS12 chassis with 12 Data Center Storage 1000GE load modules can generate up to 1.2 terabits of mixed RoCEv2 and HTTP Traffic. Congestion control is implemented in hardware for low latency

The Big Picture

The data center and with it the underlaying network are in a state of constant flux and evolution. Demands for more data, more bandwidth and less latency are not going to go away anytime soon. In order to stay on top of these demands, you need test solutions that map to the latest and greatest application. In some cases software updates to platforms like IxLoad are sufficient, in other cases for best possible results you are going to want to look at specialized load modules like the Data Center Storage load module as well.

May your DUTs exceed expectations. Thanks for reading.

Further Reading:

Data Center Storage 100GE Test Load Module:

IxLoad Overview – Converged Multiplay Service Validation

Video: Data Center Storage Switch Fabric Testing