This read-create INTEGER, in bytes, sets the committed burst size allowed by the simple port rate limiter before the CIR rate is strictly enforced, and is not applicable when the rate limit is disabled. An admin tunes this to permit brief bursts through the rate limiter without immediate penalty, balancing strict enforcement against real-world bursty traffic patterns. For example, an admin rate-limiting a port to a steady average rate might still set a modest burst size here so short bursts from normal application behavior are not immediately clamped.