Dropping every 16th byte of data sent from VM to host via pipe emulating com1...

situation:

we attempting dial modem vm using standard windows dialer connected "real" com1 on host. seems connected fine, modem responding, expected "sounds" heard when dialing. however, every 16th byte dropped seen software in host reading pipe. result, our user name , password junk , fail authentication. after loss of 16th byte, data received pipe reader expected.

hypothesis:

we must somehow overrunning "virtual uart"?

context:

windows 2012 server r2 (host)

windows 2012 server r2 (vm)

com1 in vm "redirected" named pipe serviced host software connected , forwarding data *real* com1 connected modem.

all relevant bauds set @ 9600, have experimented both high , low without success.

send/receive buffers set max size (com1, advanced settings in vm).

all different flavors of flow control have been attempted in vm (xon/xoff, hw, none).

the pipe reader not lolly-gagging....logs show *extremely* responsive in reading data.

we have disabled logging in event being adversely impacted.

requested support:

has experienced such trouble? in addition experimentation flow control, baud rates, drivers, , name it, have begun pursue chants , waving of chicken bone necklaces honor both our host , vm computers.

thanks.

alex

             

hi alex,

>>however, every 16th byte dropped seen software in host reading pipe.

do mean device or vm dropping packet?

according description, using application implement com-over-network?

if yes, hyper-v virtual switch , virtual nic not drop traffic, unless using vlan , vlan id doesn't match. 

i suppose check configuration of application.

best regards,

leo

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