serial1=nullmodem server:208.109.9.123 port:8001 transparent:1

1) the documentation (if any) isn't quite clear on the actual meaning of 'transparent' nor on wether it's parameter should be :1 or :true or whatever but it seems that with that turned on it doesn't send the extra
bytes at the start 😉 - maybe add stuff to the documentation in that matter.

2) the actual suggestion:
turns out that if you bring down the server dosbox doesn't reconnect by itself. there is no mention of an option to force it to retry/persist. basically it just keeps running. just that it's not connected anymore and will never connect again. 😜
maybe not such an issue for games. but it is for data communications software.

tcpconnect(){
while(1){
if(sock!=-1)close(sock)
if socket()==-1 continue
if connect()==-1{sleep(1);continue}; //mind the 1 second delay to keep it from hammering targets that are rejecting
break
}

main():
sock=-1;
tcpconnect();

select/read/write: if(bytes)==0 || select==-1 (invalid file descriptors in set) -> tcpconnect()

other than the 'not reconnecting in case of server or network failure' stuff it works fine. also with somewhat more complex stuff 😉
(in this case ax.25 kiss over tcp from older dos programs thinking they talk to a serial tnc... no issues protocol wise. just needs some sort of reconnect to 'keep running'. always. 😉