[Pvfs2-developers] BMI send implemtations

[Scott Atchley]

Hi all,

What is the purpose of the Request To Send (RTS) and Clear To Send  
(CTS) messages in the IB and other BMI implementations? Is it to  
check if resources are available on the receiver (i.e. to see if a  
matching receive has been posted) or to explicitly tell the receiver  
to post a receive?

 From my discussions with Sam and Murali, they mentioned that in any  
exchange the first message is always unexpected. These messages are  
guaranteed to below a preset size (determined by the BMI method). Any  
expected message should then find a matching receive on the peer. If  
so, why use the RTS and CTS messages?

Scott