TCB

Transient Capture Buffer (TCB) is a buffer technology used to capture and store temporary data, commonly found in high-performance computing and data processing systems. It enhances network visibility by capturing critical data related to packet drops, enabling network operators to diagnose and troubleshoot rare and unexpected packet loss incidents. TCB plays a crucial role in storing and managing high-speed data for analysis and debugging. The key difference between TCB and traditional buffers lies in its ability to handle high-speed data flows more efficiently and provide short-term storage for transient data. Traditional buffers are generally used for more routine data transfer and storage tasks with longer buffering delays. In contrast, TCB focuses on capturing data in short time windows for quick response to network anomalies.

TCB is widely used when data integrity and efficient transmission are crucial, such as in telecommunications, data centers, and cloud computing environments. In these high-demand settings, TCB ensures stable data transmission under extreme throughput and low-latency conditions, safeguarding the reliability and performance of the network during critical moments.

The TCB system consists of two key buffers that work together to provide comprehensive diagnostics:

TCB Buffer (Circular Buffer): The TCB Buffer is a circular buffer used to capture transactions around the vicinity of a specific packet drop event. Unlike traditional linear buffers, a circular buffer overwrites older data as new data arrives, ensuring that the most recent transactions are always available for analysis. The TCB Buffer is responsible for storing two main categories of data:

• Packet metadata (source/destination port, timestamp, Unicast queue number, Unicast queue depth, service pool depth...)

• Raw packet data (80 bytes from the start of the packet)

Event buffer (FIFO buffer): The Event Buffer operates as a first-in, first-out (FIFO) buffer, meaning that data is processed in the order it was received, with the earliest data being the first to be retrieved. The Event Buffer plays a crucial role in recording and understanding the cause of packet drops by capturing essential metadata and analysis data.

The TCB state machine works as follows:

Idle State: TCB is enabled but not actively capturing data.

Pre-Trigger State: System captures packets using the pre-sample rate when the queue length exceeds the start threshold value.

Post-Trigger State: When packet drops occur in the queue, the state machine transitions from the pre-trigger to the post-trigger state..

Transition Back to Idle State: System stops capturing packets and returns to idle state when queue length drops below the stop threshold value.

Frozen State: When the number of captured packets reaches the frozen number or the capture timer expires, the state machine transitions from the post-trigger to the frozen state. The state machine analyzes the drop reason and dropped packet characteristics and sends the data report to the gRPC module, which reports them to an NMS. Finally, it returns to the idle state

In high-performance networking, ensuring data integrity and efficient transmission is crucial. The TCB plays a key role in capturing, processing, and managing data flows, helping to prevent packet loss, mitigate traffic bursts, and optimize overall network performance. Below are the core functions of TCB and how it enhances data handling in modern networks.

Data Capture: TCB temporarily stores data during transmission, ensuring that no data is lost or omitted. Acting as a buffer, it preserves critical packet information, allowing for accurate monitoring and analysis of network events.

Data Processing: The data stored in the buffer can be further processed or analyzed, enhancing the system's data handling capabilities and efficiency. This allows for in-depth diagnostics, performance optimization, and troubleshooting of network issues.

Mitigating Data Bursts: TCB helps manage sudden bursts of traffic by buffering transient data spikes. This prevents network congestion and overload, ensuring stable and efficient data flow without packet loss.

Data Transmission: During transmission, TCB serves as an intermediate storage area, maintaining the continuity and integrity of data. This ensures smooth and reliable data transfer, particularly in high-performance network environments.