Symptom:
Timeout discards(drops) are not being counted as output discards on the fc interface. The "discards" counter will not include any frames discarded due to them reaching the congestion-drop threshold.
Example:
<pre>
5548-2# show int fc2/1
fc2/1 is up
    Hardware is Fibre Channel, SFP is short wave laser w/o OFC (SN)
    Port WWN is 20:41:54:7f:ee:d9:4c:80
    Admin port mode is F, trunk mode is off
...
      800 frames output, 1703820 bytes
        0 discards, 0 errors                       <<<<< Output discards are listed as 0
      0 input OLS, 0 LRR, 0 NOS, 0 loop inits
      1 output OLS, 1 LRR, 0 NOS, 0 loop inits
    last clearing of "show interface" counters never
      16 receive B2B credit remaining
      66 transmit B2B credit remaining
      0 low priority transmit B2B credit remaining
    Interface last changed at Thu Aug  9 23:59:58 2018
</pre>

Conditions:
Applies to NX-OS 7.x releases and above.