Acknowledgments aren't required, since the data coming back is an implied acknowledgment that the command was received. If data is not received within a certain amount of time, then the command is re-sent. Since the original command packet contained a DLC CRC error, the receiving Ethernet adapter discards the packet, since the data inside the packet can't be trusted. So the seven CRC packets in our analysis were adding a 3.5 second delay to the file transfer for every 100 KB of data transferred. Since this re-try is very fast, in the tens of microseconds, very little degradation is noticed.
Errors are always relative to the workstation and network.
For example, a network-wide three percent collision rate is more than tolerable, provided the collisions are randomly dispersed. We examined all the components in the system between the suspect workstation and the hub, and everything checked out, including the adapter and all the wiring up to the hub. Then we discovered that the hub was in turn connected to a multiport 10BaseT card plugged into a hub tha t housed a multiport bridge card. As it turned out, the CRC errors were occurring between the multiport 10BaseT card and the suspect station that was attached to the hub. Once again, the wiring for this connection checked out.