text: Figure 11-97 Scaling of host I/O 
  
  The equation that can describe the approximate minimum bandwidth that is required 
  between two systems with < 5 ms round-trip time and errorless link follows: 
  
  Minimum intersite link bandwidth in Mbps > Required Background Copy in Mbps + 
  Maximum Host I/O in Mbps + 1 Mbps heartbeat traffic 
  
  Increasing latency and errors results in a higher requirement for minimum bandwidth. 