This sets the flow-control buffer size, in bytes up to a maximum of 12,288, used by this FCIP link to manage the pacing of data between the local and remote Fibre Channel fabrics over the IP transport. Sizing this buffer appropriately for the link's bandwidth-delay product matters because an undersized buffer on a high-latency, high-bandwidth FCIP link will bottleneck throughput regardless of how fast the underlying IP circuit actually is. A high-latency transcontinental FCIP link might need this buffer sized close to its 12,288-byte ceiling to keep the pipe full, whereas a short metro-area FCIP link could perform fine with a much smaller buffer.