There are a few things I would like to point out that may be of interest to NCP implementers. This has been the case almost every time I have looked at these statistics. It suggests that the RFNMs are not being lost but are rather delayed beyond the NCP timeout interval, which I believe is 30 seconds. Perhaps longer timeouts are in order. I believe this reflects differences in allocation strategies among various hosts.
Many hosts appear to send out an allocate for every data message received.
While this is reasonable for connections such as FTP data transfer connections, it imposes considerable extra traffic in the case of the single character messages that seem to be the most common on the network. The effect of this strategy is to significantly reduce the number of allocates returned for a given number of small messages received. This reduces both network traffic and control message overhead at the other end. The strategy has no effect on FTP data messages, since each message is usually large enough to reduce outstanding allocation by at least half at a single blow. Most of these seem to be piggy-backed onto other control messages, so the situation is not as awful as the figures would indicate.