Subj : Re: Question for telnet/BBS gurus.
To   : Rob Swindell
From : Mark Hofmann
Date : Tue Jun 23 2020 01:40 pm

RS> No, Telnet binary mode only affects the interpretation of the CR/LF and
RS> CR/NUL byte pairs, which most definitely are likely to be contained in
RS> many/most file transfers and thus need to have binary mode enabled to be
RS> received correctly (e.g. for chksum/crc validation purposes, if nothing
RS> else).

That appears to be what is happening in the case of the nested telnets when doing a file transfer (other than Mystic->Mystic).  

The transfer will start, get CRC errors, and eventually abort.

Mystic->Syncronet, Mystic->WWIV, GameSrv(TelnetDoor)->WWIV seem to suffer from this when doing file transfers.  What is likely happening is the "enable binary mode" is only going to the nested telnet and not both the nested and the original one. 
- Mark

--- WWIVToss v.1.52 
 * Origin:  http://www.weather-station.org * Bel Air, MD -USA (1:261/1304.0)

.