Question 1

Which statement best describes the primary function of an InfiniBand router in a high-performance computing (HPC) environment?

Options :

A : The InfiniBand router connects different InfiniBand subnets, allowing for communication between devices across multiple subnets.

B : The InfiniBand router aggregates traffic from multiple endpoints and directs it to external networks, such as Ethernet or Fibre Channel.

C : The InfiniBand router controls congestion within a subnet by distributing traffic across multiple links based on load.

D : The InfiniBand router functions as a load balancer, distributing data streams evenly across endpoints within the same subnet.

Answer: A

Question 2

Which feature of InfiniBand makes it particularly suitable for applications like artificial intelligence (AI) and machine learning (ML) workloads?

Options :

A : Remote Direct Memory Access (RDMA) for reduced CPU load and fast data transfer

B : High compatibility with legacy Ethernet switches

C : Support for Quality of Service (QoS) to prioritize traffic

D : Built-in firewall and network security features

Answer: A

Question 3

Your organization has deployed an InfiniBand fabric for a data center, but recently you have been experiencing intermittent latency spikes and congestion issues. The InfiniBand fabric is used for both storage traffic (NVMe-oF) and computational workloads (GPU training). You suspect that the congestion is caused by unbalanced traffic patterns and insufficient congestion control mechanisms. Which of the following best practices should be implemented to address congestion and latency issues in your InfiniBand deployment?

Options :

A : Increase the MTU size for all links to reduce the number of packets traversing the fabric, reducing congestion.

B : Implement Congestion Control (CC) and use ECN (Explicit Congestion Notification) to reduce latency and balance traffic loads.

C : Use copper cables with built-in flow control mechanisms to improve resilience against congestion.

D : Enable Virtual Lane (VL) arbitration and configure lossless Ethernet to ensure priority for storage traffic.

Answer: B

Question 4

A financial services company is using RDMA over InfiniBand to accelerate the processing of real-time market data between servers. The application employs zero-copy techniques to avoid unnecessary data copies during communication. However, after switching to this configuration, the company observes that CPU utilization is still relatively high during data transfers, and performance gains are less than expected. What could be the most likely reason for the suboptimal performance?

Options :

A : Zero-copy requires additional software-based data serialization, which increases CPU overhead

B : The InfiniBand adapters are not using DMA (Direct Memory Access) for data transfers

C : The application is not properly registering memory regions for RDMA operations.

D : The zero-copy mechanism only applies to small data transfers, not to larger ones

Answer: C

Question 5

In an InfiniBand fabric, you are tasked with designing a QoS policy using Virtual Lanes (VLs) to segregate traffic types. Which of the following best describes how VLs should be configured for optimal traffic management?

Options :

A : Use only two Virtual Lanes: one for high-priority traffic and one for low-priority traffic, as InfiniBand guarantees low latency for all traffic.

B : Assign a separate VL for each traffic type, ensuring that critical traffic such as management traffic is isolated from application data traffic.

C : Use a single Virtual Lane (VL) for all traffic types to reduce configuration overhead and complexity.

D : Assign bandwidth-heavy traffic and latency-sensitive traffic to the same VL to maximize network resource utilization.

Answer: B