Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 
Community Member

Explanation of TxWaitCount in FC Interface Monitor Protocol

The FC Interface Monitor Protocol lists "TxWaitCount" as "The number of times the FC-port waited due to lack of transmit credits.". Can someone plz point me to a more complete explaination of this counter? We have a couple of ports on our DS-X9032 that have very high values for TxWaitCount. What would typically cause this? TIA.

Cisco Employee

Re: Explanation of TxWaitCount in FC Interface Monitor Protocol

So, what it is that an device has sent frames to the destination. The switch now has the frame and wants to send it to the destination but the receiving device has not given the switch a buffer credit and thus, the switch has to wait to transmit. Flow control in fibre channel is based upon having a buffer-buffer credit available. This is caused when more data is destined to a device than has BB credits to accept it all.

CreatePlease to create content