03-23-2016 06:31 AM
Hi. Can anyone explain how that feature works?
I found some description of it in Admin guide but it does not say anything more than:
Buffer credit recovery allows links to recover after buffer credits are lost when the buffer credit recovery
logic is enabled. The buffer credit recovery feature also maintains performance. If a credit is lost, a
recovery attempt is initiated. During link reset, the frame and credit loss counters are reset without
I just wonder what means "credit is lost" and how will transmitting side get the understanding of it?
And what exactly the mechanism of recovery? If there were 8 bb credits on port and after sending 8 frames to connected device they did not receive any single R_RDY, will credit buffers be restores to 8 bb credits again? how soon?
03-24-2016 11:59 AM - edited 05-06-2016 06:26 AM
While we still encourage the community to assist with your post, I wanted to let you know that we have started a pilot program with TAC to help with some of the questions being asked and yours has been handed off to our TAC technicians. They will be reaching out to you shortly to gather some more information so we can get you in touch with the right engineer . I encourage you to continue to post in the community and let me know if there is any way I can help. Once your post is resolved, we will make sure to post the resolution back to the community to help other members.
04-20-2016 01:00 AM
You might want to have a look here:
There are also a lot of other articles on there which show fabric behaviour etc....
04-27-2016 01:00 PM
The reason for the lost credit could be:
There are 2 methods to resolve such issues:
But how sender or receiver could recognize these errors? To achive this there are additional counters and primitives:
Each port maintains a count between successive occurrences of BB_SCs and BB_SCr. Thus if port receives less frames between the BB_SCs and less R_RDY between the BB_SCr then it will know that something went wrong.
The recovery mechanism for FOS below the 7.0 level is Link Reset. FOS 7.0 and beyond counts the number of “missing” R_RDYs and adds the number back to the BB credit counter.