Knowledge

The pre-terminated wiring site only needs to be laid and plugged in. The three links that are most likely to overturn are path, traction and polarity. This article gives the three checks before deployment, the key points of traction control, and the segment-by-section insertion loss test method, which is suitable for the construction of the backbone of the data center.

The key points of ODF patch panel selection are explained clearly from the three dimensions of capacity estimation, fiber bending radius, and fixed and pull-out structures, helping computer room projects avoid two common pitfalls: insufficient ports and pigtail compression during the procurement stage.

The applicable boundaries of the three access methods of DAC, AOC and optical module plus jumper are divided according to the speed and transmission distance, and the selection logic of the number of server network card ports and chip compatibility is explained.

The characteristics of parameter synchronization and data set reading in the GPU training cluster are disassembled, and the architectural key points of separation of parameter network and storage network, access rate alignment and lossless mechanism activation are given.

It provides an assessment of whether 400G signals are really needed, a coarse-to-fine upgrade path, as well as transition points such as packaging compatibility, wiring accounting, and cutover sequence to avoid having to start over at once.

Explain the source of RDMA's sensitivity to packet loss, sort out the division of labor, configuration sequence and common misunderstandings between ECN early warning and PFC final analysis, and help build RoCEv2 lossless Ethernet.

Explain the definition and calculation caliber of the convergence ratio, give recommended values ​​of 1:1 to 3:1 according to three scenarios: storage, general virtualization, and AI training, and explain how the uplink ports are evenly allocated to each spine.

Compare the differences in latency, east-west bandwidth, and scalability between the traditional three-layer architecture and the Spine-Leaf two-layer architecture, and provide a basis for judging what scale should retain three layers and what signals should upgrade two layers.

The construction of 100G links between buildings is easy, but the activation is error-prone. This article gives a three-step method for commissioning: first make an attenuation budget based on the measured channels, then standardize termination and cleaning, and finally run a 24-hour error baking machine and file records to help the project start up at once and save rework.

There are still many 40G QSFP+ ports and modules in the current network. This article explains the common types of 40G modules, the key points of the breakout connection method when split into four 10G modules, and the route judgment for smooth upgrade to 100G, helping you to use the 40G in your hands wisely.