Hello,

I've run into an problem with ARQ sessions with a connection bandwidth of 200. Although in these cases the connection is established, the subsequent transfer of data frames between the stations is severely degraded. Zero, one or two data frames are transferred, then the process stalls until l the connection times out. I often see in the exception log of the server station a stream of these:

This is true only for a requested connection bandwidth of 200. The strange thing is that with exactly the same hardware and software setup, ARQ connections with a bandwidth of 500 or 2500 work fine, whether negotiation is used or not. Here's a table:

Client 2500 --> Server 2500 good
Client 500 --> Server 2500 good (negotiatebw=true of necessity)
Client 200 --> Server 2500 bad (negotiatebw=true of necessity)
Client 500 --> Server 500 good
Client 200 --> Server 500 bad (negotiatebw=true of necessity)
Client 200 --> Server 200 bad

This is repeatable here, in a test bed consisting of 2 Win10 (v1709) PCs running ARDOP_2Win 2.0.4 and ARIM 2.1, connected by 2 back-to-back USB sound cards. Connections are established and then a file listing request is made by one station to the other (it fails either way).

Below are debug and exception log excerpts from client and server TNCs for a typical case where bw=200. Immediately thereafter, success is achieved if I simply switch to a configuration using arqbw 500 or 2500, or a combination thereof, by issuing the ARQBW command to the TNCs with the new values.

Is any one else having trouble like this? I'll be happy to do more testing and send logs as time permits.

73,
Bob NW8L

Client station debug log
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