Meaning of the output values in "ovs-ofctl dump-ports"

Issue

• Would you have any good material that explains the meaning of the parameters in the "ovs-ofctl dump-ports" output?

• For instance, what does the following in the output means:

   - errs 
   - frame
   - over 
   - crc  
   - coll 

• ovs-ofctl dump-ports br-ex returns something similar to this:

[root@overcloud-controller-0 ~]# ovs-ofctl dump-ports br-ex
OFPST_PORT reply (xid=0x2): 7 ports
  port  "phy-br-ex": rx pkts=459, bytes=27336, drop=?, errs=?, frame=?, over=?, crc=?
           tx pkts=187252, bytes=7883420, drop=?, errs=?, coll=?
  port  vlan203: rx pkts=130708149, bytes=13030270734, drop=0, errs=0, frame=0, over=0, crc=0
           tx pkts=130695256, bytes=14885947966, drop=0, errs=0, coll=0
  port LOCAL: rx pkts=12770730, bytes=35315553279, drop=0, errs=0, frame=0, over=0, crc=0
           tx pkts=12435328, bytes=1437425172, drop=0, errs=0, coll=0
  port  eth0: rx pkts=644161587, bytes=119706214417, drop=0, errs=0, frame=0, over=0, crc=0
           tx pkts=655881264, bytes=105916785455, drop=0, errs=0, coll=0
  port  vlan204: rx pkts=271, bytes=23880, drop=0, errs=0, frame=0, over=0, crc=0
           tx pkts=1407, bytes=147376, drop=0, errs=0, coll=0
  port  vlan201: rx pkts=489993276, bytes=58963083249, drop=0, errs=0, frame=0, over=0, crc=0
           tx pkts=502549642, bytes=86064992592, drop=0, errs=0, coll=0
  port  vlan202: rx pkts=10178933, bytes=836033054, drop=0, errs=0, frame=0, over=0, crc=0
           tx pkts=10199602, bytes=954487817, drop=0, errs=0, coll=0